ArticlePDF AvailableLiterature Review

The Relative Health Benefits of Different Sexual Activities

April 2010
Journal of Sexual Medicine 7(4 Pt 1):1336-61

DOI:10.1111/j.1743-6109.2009.01677.x

Source
PubMed

Authors:

Although many studies examine purported risks associated with sexual activities, few examine potential physical and mental health benefits, and even fewer incorporate the scientifically essential differentiation of specific sexual behaviors. This review provides an overview of studies examining potential health benefits of various sexual activities, with a focus on the effects of different sexual activities. Review of peer-reviewed literature. Findings on the associations between distinct sexual activities and various indices of psychological and physical function. A wide range of better psychological and physiological health indices are associated specifically with penile-vaginal intercourse. Other sexual activities have weaker, no, or (in the cases of masturbation and anal intercourse) inverse associations with health indices. Condom use appears to impair some benefits of penile-vaginal intercourse. Only a few of the research designs allow for causal inferences. The health benefits associated with specifically penile-vaginal intercourse should inform a new evidence-based approach to sexual medicine, sex education, and a broad range of medical and psychological consultations.

Psychological and psychophysiological health aspects of different sexual behaviors

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Physiological health aspects of different sexual behaviors

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REVIEW

The Relative Health Beneﬁts of Different Sexual Activitiesjsm_16771336..1361

Stuart Brody, PhD

University of the West of Scotland, School of Social Sciences, Paisley, UK

DOI: 10.1111/j.1743-6109.2009.01677.x

ABSTRACT

Introduction. Although many studies examine purported risks associated with sexual activities, few examine poten-

tial physical and mental health beneﬁts, and even fewer incorporate the scientiﬁcally essential differentiation of

speciﬁc sexual behaviors.

Aims. This review provides an overview of studies examining potential health beneﬁts of various sexual activities,

with a focus on the effects of different sexual activities.

Methods. Review of peer-reviewed literature.

Main Outcome Measures. Findings on the associations between distinct sexual activities and various indices of

psychological and physical function.

Results. A wide range of better psychological and physiological health indices are associated speciﬁcally with

penile–vaginal intercourse. Other sexual activities have weaker, no, or (in the cases of masturbation and anal

intercourse) inverse associations with health indices. Condom use appears to impair some beneﬁts of penile–vaginal

intercourse. Only a few of the research designs allow for causal inferences.

Conclusions. The health beneﬁts associated with speciﬁcally penile–vaginal intercourse should inform a new

evidence-based approach to sexual medicine, sex education, and a broad range of medical and psychological

consultations. Brody S. The relative health beneﬁts of different sexual activities. J Sex Med 2010;7:1336–1361.

Key Words. Sexual Intercourse; Health Behaviors; Masturbation

Introduction

Many studies have examined purported health

risks associated with sexual activities, but few

studies have examined the potential physical and

mental health beneﬁts of sexual activities. Even

fewer studies have incorporated the scientiﬁcally

essential differentiation of speciﬁc sexual behaviors.

Sexual medicine should be concerned not only with

the treatment of ill sexual health, but the speciﬁc

evidence-based promotion of positive health.

An overview of the empirical evidence on psy-

chological and physiological differences between

sexual behaviors should inform the practice of

sexual medicine, as well as other ﬁelds, including

general medical practice, sex education, psycho-

therapy (both sexuality topics as well as sexuality as

an aspect of character), and research in physiology

and psychology.

Aim

This review aims to provide an overview of studies

examining potential psychological and physiologi-

cal health beneﬁts or correlates of various sexual

activities, with a primary focus on studies differen-

tiating the effects of distinct sexual activities. An

additional aim is a discussion of implications for

education, research, and clinical assessment and

practice.

Methods and Main Outcome Measures

Studies were identiﬁed from various sources,

including those studies conducted in the laborato-

ries of the author and colleagues, previous briefer

overview papers incorporating some aspects of

health beneﬁts associated with sexual behaviors

[1–3], and searches in PubMed and PsycInfo. The

1336

present review differs from those earlier reviews in

its breadth and (with the exception of one [1])

greater attention to differences between sexual

behaviors. There is also more discussion of

methodological issues, as well as a discussion of

implications for education, research, and clinical

assessment and treatment. The presentation is

organized largely by the nature of the health topics,

which are found under the major headings of Psy-

chological and Physiological factors (some topics,

such as pain, could have arguably been placed under

either major heading). The topics range from “soft”

variables such as relationship quality to “hard” vari-

ables such as biochemical measures. The nature of

the research designs varies greatly. Although

experimental designs generally are viewed as offer-

ing ﬁrmer evidence than correlational or risk-factor

epidemiological designs, the reader is advised to

look for convergent evidence using differing

samples and methods, optimally with examination

of some potential confounding variables.

A few studies noted in this review adjust for the

tendency of some people to underreport behaviors

that they consider to be socially undesirable.

Although it might be conjectured that elevated

social desirability response scores might measure a

propensity to actually behave in a socially desirable

manner, there is some evidence to the contrary:

social desirability scores were higher than norma-

tive values in large groups of men and women

convicted of intimate partner abuse [4]. Social

desirability response bias scores have been found

to mask the ability of greater life stress and poorer

psychological coping skills to predict athletic inju-

ries [5]. Social desirability response bias scores

predict discrepancies between (indirectly) mea-

sured and self-reported caloric consumption [6–8].

However, social desirability responding varies

between individuals and situations, and as such, is

not always a confounding factor. Interestingly,

social desirability responding might itself be asso-

ciated with predictors of poorer physical health

outcomes [9,10].

Most cross-sectional studies that focus on

inﬁrm populations have been excluded, because of

the risk of reverse causality (inability to engage in

some sexual behavior because of the inﬁrmity). In

contrast, the review includes studies that ﬁnd

sexual behavior differences in healthy adults with

regard to subtle but important longitudinal predic-

tors of future morbidity or mortality (such as heart

rate variability, and blood pressure stress reactiv-

ity). However, the issue of causal direction (includ-

ing bi-directional causality, as in vicious or

virtuous circles) needs to be pondered in any cor-

relational or risk-factor epidemiological research

design. Retrospective case-control studies might

be subject to biased recall and/or insufﬁcient

matching of cases and controls. Associations can

also be a result of a shared unmeasured third factor

(such as genetic inﬂuence) that affects both the

nominal outcome variable and the nominal predic-

tor variable. These issues apply to risk-factor epi-

demiological studies in general, not only to studies

with potentially controversial ﬁndings.

Differences between health aspects of speciﬁc

sexual behaviors (e.g., penile–vaginal intercourse

[PVI], masturbation, sex with a partner other than

PVI) are highlighted. Some of the studies examine

whether one has engaged at all in a sexual behavior

in a given time period, others examine frequency,

others examine combinations of sexual repertoires,

others examine manner of orgasm elicitation, and

others examine gross modiﬁcation of the nominal

sexual behavior (e.g., condom use or clitoral mas-

turbation during PVI).

The discussion will address the compatibility

of the observed results with both evolutionary

and early psychoanalytic theories. These two

approaches to understanding human behavior

focus respectively on which characteristics have

been most adaptive in the course of human evolu-

tion (in the sense of increasing the likelihood of

transmitting one’s genes), and the mental opera-

tions (many out of awareness) that motivate behav-

ior and are rooted in problems of childhood

psychosexual development (with implications

for chronological adults). The discussion also

describes some physiological and other possible

bases for the observed effects.

Results

Psychological Factors

Satisfaction with One’s Mental Health

In a large representative sample of the Swedish

population, PVI frequency was a signiﬁcant pre-

dictor of both men’s and women’s greater satisfac-

tion with their mental health [11]. In contrast,

masturbation was inversely associated with mental

health satisfaction in the multivariate analyses that

controlled for other sexual behavior frequencies,

and partnered sexual behaviors other than PVI

were uncorrelated with mental health satisfaction

[11]. The same large Swedish survey also revealed

that women who had experienced vaginal orgasm

(deﬁned quite conservatively as having “had an

orgasm solely through the movement of the penis

Healthy Sex 1337

J Sex Med 2010;7:1336–1361

in the vagina”) were more satisﬁed with their

mental health than the minority of women who

had only experienced orgasms through direct cli-

toral manipulation [12]. The Swedish survey used

in those studies was reported to not be affected by

social desirability response bias [13,14].

Intimate Relationship Quality

In a small study of Portuguese women, frequency

of PVI (FSI) correlated positively with Perceived

Relationship Quality Components (PRQC)

Inventory dimensions of satisfaction, intimacy,

trust, passion, and love [15]. In contrast, frequency

of partnered sexual behaviors other than PVI was

uncorrelated with the PRQC dimensions. Mastur-

bation frequency was inversely associated with

love. PVI orgasmic frequency correlated positively

with the PRQC dimensions of satisfaction, inti-

macy, passion, and love. PVI orgasmic consistency

(proportion of PVI occasions resulting in PVI

orgasm) was inversely associated with masturba-

tion frequency. When PVI frequency was con-

trolled in a partial correlation procedure,

noncoital sex frequency was associated with less

global relationship satisfaction, and noncoital

partnered orgasm frequency was associated with

less love. Social desirability scores did not con-

found the associations [15]. These results are fairly

consistent with an American study which found

that 100% of maritally and sexually satisﬁed

wives—but only 68% of the maritally satisﬁed yet

sexually dissatisﬁed wives—had PVI among their

sexual activities in the past week, that masturbating

the male to orgasm was reported by 4% of the

maritally and sexually satisﬁed but 30% of the

maritally and sexually dissatisﬁed women, and that

cunnilingus frequency was unrelated to satisfac-

tion [16]. Although not emphasized in Kinsey’s

writings, Kinsey researchers found that “marital

happiness” was associated with female coital

orgasm [17]. In a large representative sample of

the Swedish population, independent multivariate

predictors of men’s relationship satisfaction were

greater frequency of PVI, but lesser frequencies of

masturbation, anal sex, and oral sex (for women,

the independent multivariate predictors were

simply greater frequency of PVI and lesser fre-

quency of masturbation) [11].

Alexithymia

Alexithymia is a relative inability to perceive, iden-

tify, and express emotions. It is a personality trait

associated with some forms of psychopathology,

associated with the use of immature psychological

defense mechanisms and also associated with the

use of distraction as a coping mechanism [18].

Studies of Swiss and American patients found that

alexithymia was associated with hypoactive sexual

desire [19], sexually dysfunctions, and paraphilias

[20].

FSI (but not frequency of either masturbation

or of partnered sexual activity excluding PVI), as

measured by both sexual behavior diaries and

recall, was associated with less alexithymia (hence,

more emotional integration) as measured by the

Toronto Alexithymia Scale (TAS-20) in a sample

of healthy German women [21]. High social desir-

ability scorers were excluded from the analysis.

In addition to the use of the validated psycho-

metric measure of alexithymia, the association

between habitual sexual behaviors and the labora-

tory measured integration of vaginal responses

into psychological arousal can inform the under-

standing of emotional integration. Research has

revealed that the awareness and integration of

vaginal sensations into women’s subjective sense of

sexual arousal varies as a function of their habitual

orgasm sources.

Several studies have concurrently examined

women’s subjective and vaginal response to erotica

(videotape and/or fantasy), and in contrast to

studies with men, most of the studies showed that

overall, there was poor concordance between

women’s vaginal and subjective sexual arousal

responses. Based on the inference that women who

have PVI orgasms were more likely than coitally

anorgasmic women to successfully integrate their

physical and emotional feelings, it was hypothe-

sized [22] that greater orgasmic consistency during

PVI (but not during other sexual behaviors) would

be associated with better concordance of vaginal

and subjective sexual arousal.

Healthy menopausal Dutch women completed

a questionnaire on their PVI, masturbation, and

noncoital partner sexual frequencies for a 1-month

period, and noted for each occasion whether

orgasm occurred; orgasm consistency was the per-

centage of each sexual event type resulting in

orgasm [22]. In the laboratory, they were exposed

to erotic videotapes, nonerotic (control) video-

tapes, and also asked to engage in epochs of sexual

fantasy. They rated their sexual arousal, and their

vaginal response was measured with a vaginal pho-

toplethysmograph that assesses vaginal vaso-

congestion (the device allowed measurement of

vaginal pulse amplitude). The correlation

(z-transformed) of subjective and vaginal response

was the index of concordance. As hypothesized,

concordance was signiﬁcantly associated with PVI

1338 Brody

J Sex Med 2010;7:1336–1361

orgasm consistency, but not consistency of orgasm

during other sexual activities: women who regu-

larly had PVI orgasms had excellent concordance

of vaginal and subjective arousal, but other women

(even those who orgasmed reliably through means

other than PVI) had a functional disconnection

between their vaginal arousal and their mental

experience. The results were not confounded by

social desirability responding.

Also of note were the ﬁndings that (i) orgasm

consistency rates were similar for PVI and for non-

coital sexual activities, and (ii) PVI and masturba-

tion orgasm consistency were uncorrelated. This

latter ﬁnding implies that most of the coital

orgasms were most likely not masturbatory clitoral

orgasms, but real vaginal orgasms (i.e., female

orgasm induced by penile–vaginal stimulation per

se). The latter ﬁnding also has implications for sex

therapy, as masturbation and intercourse orgasms

are substantially different.

The same pattern and magnitude of vaginal-

subjective arousal concordance results were found

in a replication study [23] involving young Dutch

women (all of whom had current partners; in the

ﬁrst study a few of the women did not have current

partners).

It is speciﬁcally PVI orgasm consistency that is

related to integration of vaginal response into the

appraisal of arousal. An analogy might thus be

made between these ﬁndings and the aforemen-

tioned ones on alexithymia: in both cases an

index of speciﬁcally and exclusively PVI reward

(frequency [21] or orgasm consistency) was

associated with an index of greater awareness

of feeling (vaginal sensation or differentiated

emotions).

Immature Psychological Defense Mechanisms

Psychological defenses are processes, generally

operating outside awareness, that reduce distress

caused by emotional conﬂict. Immature (maladap-

tive) defense mechanisms involve a distortion of

reality and/or impairment of awareness, and they

are associated with a variety of indices of poorer

mental health and relatedness, including psycho-

logical immaturity and lesser ability to relate inti-

mately with the opposite sex [24,25]. Immature

defense mechanisms are associated with a variety

of psychiatric disorders [26–29]. According to

early psychoanalytic theories, psychological

immaturity (psychosexual immaturity, with its

concomitant greater use of immature defense

mechanisms) could lead to inhibition of frequency

and appreciation (including vaginal orgasm) of

PVI in favor of other or no sexual behaviors, with

noxious consequences for mental health and inti-

mate relationships.

In a sample of healthy Portuguese women,

vaginal orgasm (triggered solely by PVI) was asso-

ciated with less use of immature defenses [24].

Defenses were measured with the Defense Style

Questionnaire, a well-validated (including associa-

tion with various psychopathologies) measure of

immature, neurotic, and mature defenses [26,30].

Vaginal orgasm was associated with less overall use

of immature defenses, as well as with less use of the

speciﬁc component immature defenses: somatiza-

tion, dissociation, displacement, autistic fantasy,

devaluation, and isolation of affect. Orgasm from

clitoral stimulation or combined clitoral–

intercourse stimulation was not associated with

less use of immature defenses, and was associated

with more use of some immature defenses (e.g.,

orgasm from noncoital partner activity in the past

month was associated with the defense of dissocia-

tion). In one multivariate analysis, both (i) any

masturbation orgasm in the past month and (ii)

less vaginal orgasm consistency, made independent

contributions to the statistical prediction of imma-

ture defenses. In another regression analysis, (i)

any use of extrinsic clitoral stimulation for inter-

course orgasm and (ii) lack of any vaginal orgasm,

made independent contributions to the statistical

prediction of immature defenses. Vaginally anor-

gasmic women had immature defenses scores com-

parable to those of established (depression, social

anxiety disorder, panic disorder, and obsessive–

compulsive disorder) outpatient psychiatric

groups. Results were not confounded by social

desirability responding [24].

A study of predominantly Scottish women who

completed an anonymous Internet-based survey

[31] provided a cross-cultural replication of the

results obtained in the Portuguese sample. Greater

use of immature psychological defense mechanisms

was associated with lesser vaginal orgasm consis-

tency, with any orgasm from clitoral masturbation

during PVI, and with greater frequency of mastur-

bation orgasm. Immature psychological defense

mechanisms were also associated with greater fre-

quency of masturbation during PVI, and with fre-

quency and orgasm frequency of both anal sex and

vibrator use. Immature psychological defense

mechanisms were also associated with greater

quantity of alcohol consumed before sex [31].

Condoms impair many aspects of PVI, includ-

ing intimacy and sensation [32]. Freud opined that

condom use during PVI, like sexual activities other

Healthy Sex 1339

J Sex Med 2010;7:1336–1361

than PVI, led to a detrimental effect on orgasm

that fueled the neuroses. More psychologically

immature people might prefer condoms for PVI as

a means of reducing intimacy and/or such reduc-

tion might hinder psychological growth. Indeed,

research indicates that condom users do have

poorer relationship quality with their partners

[25,33]. In a study of healthy Portuguese adults,

frequency of PVI with condoms correlated directly

with use of immature defenses. In contrast, fre-

quency of PVI without condoms correlated

inversely with use of both immature and neurotic

defenses. Results were not confounded by rela-

tionship status, age, cohabitation, or social desir-

ability responding. Regression analyses revealed

that immature defenses were independently pre-

dicted by condom use for PVI and by masturba-

tion orgasms (for both sexes). For women,

additional predictors were orgasm from clitoral

masturbation during PVI, and lack of vaginal

orgasm. The results are consistent with condom

use during PVI being associated with psychologi-

cal immaturity and predisposition to poorer

mental health [25].

Depression

Higher masturbation frequency (and even the

desire for more masturbation) is associated with

depression [34–36], and masturbation is associated

with less happiness [37]. The association of mas-

turbation with depression is unlikely to be a result

of simply a lack of PVI, because more masturba-

tion and less PVI make independent contributions

to less satisfaction with relationships, sex life, life

in general, and one’s mental health (the multivari-

ate analyses also examined some partnered sexual

activities other than PVI, and revealed that anal

and oral sex frequency also have independent

inverse associations with some of the satisfaction

indices) [11].

It is likely that only unfettered, real PVI has

important mood-enhancing beneﬁts. A study of

young women in the United States found that not

only did Beck Depression Inventory scores worsen

with increasing time since last PVI (i.e., lower FSI

is associated with more depression), but the use of

condoms obliterated the apparent antidepressant

effects of PVI [38]. Depressive symptoms and

suicide attempts among women who used

condoms were proportional to the consistency of

condom use: more condom use means more

depression and more suicide attempts. The

depression and suicide association with condom

use was not because of confounding by relation-

ship duration, and there were no differences in

depression between those in and not currently in

a relationship. The investigators suggested that

their results (the results were reportedly repli-

cated, but the details of the replication have not yet

been published in detail [39]) might be a result of

intravaginal absorption of seminal prostaglandins

(as well as possibly seminal testosterone, luteiniz-

ing hormone [LH], and oxytocin) improving the

mood of women, but the researchers did not

measure the relevant chemicals in the individual

research participants. Even among women who

rarely or never used condoms, depressive symp-

toms were associated with urinating after inter-

course [39], which the investigators noted would

decrease the quantity of seminal components that

could be absorbed. Compared with women who

did not use condoms at all, consistent condom

users were both more depressed at baseline and

also evidenced a worsening of their mood during a

longitudinal study in the United States [33].

Although there might be a direct chemical antide-

pressant effect of semen absorbed from the vagina,

the large difference in mood and suicidality might

also be a result of intercourse with condoms not

really being intercourse, but something akin to

mutual masturbation with the same latex device.

One group that has both elevated rates of mas-

turbation [40] and of partnered sexual activities

other than PVI is homosexuals. Large representa-

tive surveys have found much higher rates of sui-

cidal ideation, mood disorders, substance use

disorders, and other psychiatric disorders in homo-

sexual men and homosexual women than

in their heterosexual counterparts (including in

studies conducted in what is probably one of the

most pro-homosexual countries: The Netherlands)

[41–43]. Although it was noted that among homo-

sexual men, perceived discrimination was associ-

ated with suicidality [43], it was not made clear that

the defensive process of attributing one’s bad feel-

ings to other people is itself part of the process of

depression for some people [44]. In a large

UK-based survey, 61.7% of homosexual men who

had sex with a man in the past year reported receiv-

ing ejaculate in their mouth (although 97.2%

reported performing fellatio at all) and 42.2%

reported receptive anal intercourse without a

condom in the past year [45] (unfortunately there

was not more precise quantiﬁcation of frequency of

the behaviors, except that in the updated version of

the survey, 24% reported receptive anal intercourse

without a condom in the past month, and an addi-

tional 18.5% reported it over a month but less than

1340 Brody

J Sex Med 2010;7:1336–1361

a year ago [46]). Thus, most homosexual men (who

were active in the past year) appear to have the

opportunity for absorption of seminal components

at some location within the alimentary canal. The

combination of high rates of depression despite the

opportunity for absorption of seminal components

suggests explanations including some combination

of: site-speciﬁc or sex-speciﬁc effects of seminal

component absorption (i.e., vaginal absorption has

important antidepressant effects not afforded by

alimentary absorption), variations in frequency of

seminal exposure, or overwhelming genetic or psy-

chosexual developmental effects linking homo-

sexuality and depression. A recent large twin study

revealed that not only do nonheterosexual men and

women have signiﬁcantly higher neuroticism and

psychoticism scores than heterosexuals (implying

elevated psychiatric risk), but also that there is a

signiﬁcant genetic correlation between nonhetero-

sexuality and both neuroticism and psychoticism,

but no signiﬁcant environmental correlation with

nonheterosexuality. This implies that any common

cause of both nonheterosexuality and psychiatric

risk is likely to be genetic rather than environmen-

tal [47].

Other Psychiatric Disorders

In a study [48] comparing Scottish schizophrenics

with controls of the same age, sex, and postal code,

it was found that the schizophrenic men were

several times more likely to report a zero FSI than

were controls, and less likely to report intercourse

of at least weekly. However, they were not more

likely to report abstaining from masturbation or

masturbating at least once weekly. Similarly,

schizophrenic Scotswomen in the study were more

likely to report a zero FSI than controls, but they

did not differ in their masturbation frequency

from controls.

Although some antipsychotic medications

might cause sexual dysfunction and low desire (for

some, at least in part through prolactinergic

mechanisms) [49], there is also evidence that

untreated schizophrenics have low desire for sex

with a partner, and other studies also indicate that

schizophrenics have low rates of partnered sexual

activity but elevated rates of masturbation [49].

Besides the issue of social skills deﬁcits, the low

PVI frequencies among schizophrenics might be

in part the result of wanting to avoid intimacy.

Apparently the tendency toward anhedonia

(inability to experience pleasure) among schizo-

phrenics does not limit masturbation, only PVI

pleasure. The presence of another person during

sexual activity, particularly for PVI, the most emo-

tionally intimate sexual activity, might be aversive

to many schizophrenics. Failure to develop a stable

integrated self might also impair appreciation of

PVI, particularly PVI orgasm. These aspects of the

schizophrenic situation might be viewed on a con-

tinuum with the rest of the population, such that

there are many nonpsychotics who are would be

overburdened by the emotional intimacy and over-

whelming pleasure that PVI can provide.

Czech female schizophrenics, manic-depressives,

neurotics, anorexics, and a control group of gyneco-

logical spa patients were interviewed regarding

their sexual histories [50]. The manic-depressive

(bipolar) patients did not differ from the control

group in their prevalence of PVI orgasmic

response, but the schizophrenics, neurotics, and

anorexics all had lower rates of coital orgasm. Thus,

it was not only the schizophrenics, but women with

some quite different forms of psychological prob-

lems that were impaired in their ability to orgasm

from intercourse.

Similarly, women with neurotic disorders were

less likely to have PVI orgasms than were a group

of women without neurotic disorders. However,

they were no less likely to have orgasms from

direct clitoral stimulation [51].

A similar pattern was found in a Czechoslovak

study comparing prostitutes with nonprostitutes

[52]. The prostitutes were less likely than the

control group to orgasm during PVI. Prostitutes

(especially street prostitutes) have a high preva-

lence of various forms of psychopathology, includ-

ing antisocial personality disorder, borderline

personality disorder, dissociative disorder, depres-

sion, schizophrenia, and other psychiatric and

personality disorders [53]. This psychopathology,

which includes psychological processes dissociat-

ing the experience of PVI, might contribute to the

high mortality rate of prostitutes [53,54].

Successful nonhormonal treatment of erectile

dysfunction led to an increase in FSI, a concomi-

tant decrease in masturbation frequency, and a

decrease in psychiatric symptoms [55].

Physiological Factors

Analgesia and Pain

Prostatodynia is characterized by urinary symp-

toms and pelvic pain suggestive of prostatitis but

with a nonpathological prostate examination and

without signs of inﬂammation or infection in pro-

static secretions. In a report on prostatodynia [56]

in United Nations peacekeeping forces, the occur-

rence of the disorder was associated with not

Healthy Sex 1341

J Sex Med 2010;7:1336–1361

having PVI, and it resolved with recommence-

ment of PVI. However, masturbation led to either

no improvement or to an exacerbation of pain

symptoms.

Vaginal stimulation has been shown to have

substantial analgesic properties, far greater than

clitoral stimulation [57]. The effects are not attrib-

utable to distraction [58], and appear to not be a

result of an opiate-type process [59]. One risk for

women with some sexual pain disorders is the

learned avoidance of the potentially most analgesic

and psychologically fulﬁlling sexual behavior.

Vaginal and Pelvic Muscle Function

A review of the literature on female genito–genital

reﬂexes concluded that vaginal intercourse helps

to maintain vaginal and pelvic function, including

through penile thrusting triggering reﬂex muscu-

lar contractions that maintain and improve vaginal

function [60]. There were also indications that the

presence of seminal component prostaglandin

PGE1 in the vagina after ejaculation might main-

tain vaginal oxygenation and blood ﬂow. Improv-

ing blood ﬂow could be expected to support sexual

response and vaginal health (and perhaps general

health). Using condoms deprives women of many

beneﬁts, including those blood ﬂow and oxygen-

ation beneﬁts.

Functional Musculoskeletal Disturbance

Some theories of personality and psychotherapy

have proposed a link between chronic muscle

blocks and disturbances of both character and

sexual function [61]. Regardless of whether the

sites of chronic muscle blocks (or chronic muscle

ﬂaccidity) have metaphorical meaning, they might

be both an indicator and mechanism for impaired

function, including sexual function. A study exam-

ined the association of general everyday body

movement with history of vaginal orgasm by

asking healthy young Belgian women with known

histories of either vaginal orgasm or vaginal anor-

gasmia (50% from each group) to be videotaped

walking on the street; their vaginal orgasmic status

was judged by trained (in the Functional-

Sexological school) sexologists blind to their

history [61]. History of vaginal orgasm was diag-

nosable at far better than chance level (81.25%

correct). The gait of the vaginally orgasmic

women was characterized by being physiologically

normal, and manifested ﬂuidity, energy, sensuality,

freedom, and absence of both ﬂaccid and locked

muscles (greater pelvic and vertebral rotation were

characteristic of the vaginally orgasmic women).

Clitoral orgasm history was unrelated to both

vaginal orgasm history and vaginal orgasm rating.

The report also noted previous studies that differ-

entiated homosexual and heterosexual men and

women on the basis of other aspects of gait, and

discussed functional musculoskeletal issues, the

effect of the musculature on sexual function, and

implications for sexual therapy [61].

Metabolism and Nutrition

A study of healthy German adults revealed that a

(physician-measured) slimmer waist (for men and

the sexes combined) and slimmer hips (for men and

women) were each associated with greater PVI

frequency [62]. In contrast, slimmer waist and hips

were associated with lesser masturbation frequency

(men and the sexes combined), and noncoital part-

nered sexual activity had a less consistent associa-

tion with slimness. Waist and hip circumference

were associated inversely with PVI importance for

men. Cohabitation status was an independent pre-

dictor of PVI frequency, and did not confound the

association of slimness with sexual behavior. Of

note, the effects were obtained despite exclusion of

obese and medically unﬁt subjects from the study.

Persons with high social desirability scores were

also excluded from the analyses.

In addition to issues of attractiveness (likely

rooted in evolutionary processes that favor

healthier partners), higher body fat levels are asso-

ciated with lower testosterone levels and with less

brain dopamine activity, and overeating tends to

increase brain serotonergic tone. These factors

might impair sexual desire and/or function, espe-

cially the most complex and evolutionarily relevant

sexual behavior: PVI [62]. Similar differential

sexual behavior associations with slimness have

been observed in other species: when presented

with slim females, both slim and obese male rats

hold the females and lick the vaginal region, but

obese males have a much lower PVI frequency

than the slimmer males [63]. Although in some

human societies, there is a tendency for men to

ﬁnd heavier women more attractive, these societies

tend to be characterized by food scarcity (or

limited food storage), making the issue of energy

storage within the potential fetus bearer more evo-

lutionarily salient than the issue of the various

morbidities associated with overweight (factors

that become more salient when food scarcity is not

a major issue) [64].

In societies in which food scarcity is not a

problem, people who enjoy PVI might make

efforts to remain sexually desirable to partners by

staying slim. Studies have indicated that adults

1342 Brody

J Sex Med 2010;7:1336–1361

who report having been physically or verbally

abused in childhood or adolescence are more likely

than others to be overweight or obese [65]. More

importantly, a review of longitudinal studies

reported that hostility, anger, and depression lon-

gitudinally predict the development of higher

levels of adiposity (and other aspects of the meta-

bolic syndrome) [66]. It would not be surprising if

a history of dissatisfaction with intimate relation-

ships leads to self-destructive and intimacy avoid-

ing behaviors (including speciﬁcally minimizing

PVI frequency).

Ascorbic acid (vitamin C) has many functions

(including reduction of approach anxiety, modula-

tion of brain dopaminergic and noradrenergic

activity, cardiovascular support, oxytocin secre-

tion, and reduction of stress [67,68]), some of

which might support sexual behavior and some of

which might only be manifest at high doses. A

double-blind randomized controlled trial of high-

dose (14 days of 3,000 mg/day sustained release)

ascorbic acid in healthy young German adults led

to the ﬁnding that ascorbic acid caused an increase

in PVI frequency, but not in frequency of mastur-

bation or of partnered sexual behaviors other than

PVI [69]. The ascorbic acid also improved mood.

The results were not confounded by social desir-

ability responding. Exploratory analyses revealed

that the effect was largely a result of the response

of women in the study. However, the seeming sex

difference might be attributed to young women

perhaps being more likely than young men to

fulﬁll rapidly any increased desire (caused by more

optimal nutrition) within the 14-day recording

period.

Cardiovascular Health

Resting heart rate variability (HRV, an index of

autonomic cardiac regulation) reﬂects heart rate

ﬂuctuations in response to subtle homeostatic

demands, including the differing autonomic

effects of inspiration and exhalation. Resting HRV

is driven largely by the parasympathetic nervous

system (particularly the vagus nerve), which also

has a role in sexual arousal. HRV is longitudinally

predictive of lower mortality rates among both

normals and persons with a history of heart disease

[70,71]. Psychophysiological studies found that

greater HRV is associated with indices of better

mood, attention, self-regulation, and responsive-

ness to emotional experience. HRV is also associ-

ated with fewer antisocial personality features, less

sexual dysfunction, and perhaps with pair-bonding

processes [70,71]. In healthy German adults,

greater HRV was associated with greater PVI fre-

quency, but not frequency of either masturbation

or of noncoital partnered sex [71]. HRV was also

associated with greater subjective importance of

PVI. These results were obtained after exclusion

of persons with high social desirability scores. The

results were replicated in a larger healthy German

sample [70] and also found to be unconfounded by

the various candidate variables that were exam-

ined. There were no sex differences in these sta-

tistical relationships. Thus, speciﬁcally PVI but

not other sexual behavior was associated with an

important measure of better homeostasis, better

parasympathetic tone, lower mortality risk, and

better psychological function (including better

relatedness). Of course, given the correlational

design, it is unclear to what extent better HRV

leads to more PVI and appreciation thereof, to

what extent more PVI leads to better HRV, and to

what extent some other factors (such as genetics)

inﬂuence both HRV and PVI.

In the ﬁrst of the two HRV studies [71], but not

the second [70], greater PVI (but not other sexual

behaviors) was also associated with lower resting

diastolic blood pressure. In an Italian study, newly

diagnosed, never treated hypertensive married

men aged 40–49 had an FSI 25% lower than a

control group of men who had blood pressure in

the normotensive range [72].

Blood pressure reactivity to acute stress is a risk

factor for the development of hypertension and

left ventricular hypertrophy, as well as for myocar-

dial infarction or death in susceptible persons. It is

mediated by increased sympathetic and decreased

parasympathetic nervous system activity (the latter

being largely a withdrawal of vagus activity). In a

study of healthy German adults, blood pressure

was recorded at baseline, after being instructed to

prepare a speech, after giving the speech to an

unsupportive audience for 5 minutes (plus 5

minutes of time-pressured verbal arithmetic), and

after a 10-minute recovery period, as per the pro-

tocol of the standardized Trier Social Stressor Test

[73]. The blood pressure responses were analyzed

as a categorical function of whether participant

diaries indicated that they engaged at all (in the

past 14 days) in PVI, masturbation, or partnered

sexual activity in the absence of PVI the same day

[73]. Persons with high social desirability scores

were excluded from the analyses. Persons who

engaged in PVI but no other sexual behaviors

(except partnered sexual activity the same day as

PVI) during the fortnight had not only statistically

signiﬁcantly less, but markedly less, blood pressure

Healthy Sex 1343

J Sex Med 2010;7:1336–1361

increase to the stressor than did persons engaging

in other or no sexual activities. They also had

faster recovery from the stressor (which some

researchers suggest might be even more important

for health than more moderate stress reactivity).

Persons who engaged in PVI but also engaged in

either masturbation or exclusively noncoital part-

nered sexual activity on other days had results

intermediate between the PVI-only group and the

noncoital partnered sexual activity only or mastur-

bation only groups (who did little or no better than

the no-sex group) [73]. Overall, masturbation fre-

quency was correlated with higher (worse) blood

pressure reactivity.

Results were not confounded by any of the

many demographic, physiological, psychological,

or behavioral (including exercise minutes per

week) candidate variables that were evaluated. The

blood pressure reactivity difference between dif-

ferent sexual behavior groups was at least numeri-

cally greater than differences associated with the

many psychological, physiological, social, and

behavioral variables that have been examined in

the sizeable psychophysiological literature on

blood pressure stress reactivity in normals [73].

The pattern of results suggest not only that it

is speciﬁcally PVI (rather than other sexual

behaviors) that is associated with optimal cardio-

vascular “protection” from stress, but also that the

beneﬁts are not simply due to having a partner.

The study indicated that engaging in masturba-

tion or even partnered sexual behavior that

excludes PVI on some days detracts from the ben-

eﬁts of PVI. There are several possible reasons

for this effect, including: (i) partial (rather than

complete) avoidance of PVI in favor of other

sexual activities, (ii) approaching PVI with a psy-

chological set akin to the other sexual activities,

and (iii) the beneﬁcial effects of PVI being par-

tially offset by untoward effects of the other

sexual activities.

A within-subjects laboratory study [74] com-

pared the exercise value (oxygen uptake, and blood

pressure and heart rate stimulation) of men

engaged in: masturbation, masturbation by a

partner, and two intercourse positions (man on top

and woman on top). PVI produced greater dura-

tion of heart rate elevation and substantially

greater oxygen uptake at orgasm than the other

activities [74]. Although the exercise value was

greatest for male on top (probably at least in part

because of greater motor activity), the woman on

top PVI was still superior to either of the manual

forms of penile stimulation.

Pre-Eclampsia

Among the several studies reporting on the asso-

ciation between pre-eclampsia and less (unfet-

tered) PVI is the report concluding that “birth

control methods that prevent sperm exposure may

play a role in the etiology of pre-eclampsia” (p.

3143) [75] and those reporting an odds ratio of

17.1 for pre-eclampsia associated with the combi-

nation of <4 vs. >12 months of “cohabitation” in

combination with barrier contraceptive use [76].

Fellatio is also associated with decreased risk of

pre-eclampsia: 44% of pre-eclamptic women, but

82% of controls reported fellatio before the index

pregnancy [77]; however, that study did not assess

frequency of PVI.

Hormonal and Neurohormonal Effects

In addition to any effects of testosterone levels

supporting PVI frequency, there is evidence of the

causal arrow pointing in the other direction [78].

Successful restoration of erectile function, through

any of a variety of forms of nonhormonal treat-

ment (psychological, surgical, vacuum device,

yohimbine, prostaglandin E1) led to a return of

testosterone levels to the typical range for the

population. Men who responded to treatment with

an FSI of at least 8 per month showed greater

testosterone increases than men who responded

with an FSI of 1–7, who in turn showed greater

testosterone levels than nonresponders [78]. As the

authors noted: “Since the pre-therapy low test-

osterone levels were independent of the aetiology

of impotence, we hypothesize that this hormonal

pattern is related to the loss of sexual activity, as

demonstrated by its normalization with the

resumption of coital activity after different thera-

pies. The corollary is that sexual activity may feed

itself throughout the increase in testosterone

levels” (p. 385). The same research group found

that the FSI response to sildenaﬁl or tadalaﬁl treat-

ment also led to a corresponding decrease in serum

LH [79]. These latter results need to be consid-

ered in light of recent experimental evidence that

chronic administration of sildenaﬁl itself stimu-

lates testosterone secretion in mice [80].

In a randomized trial of coitus (vs. no coitus) for

the treatment of Nigerian women’s menopausal

hot ﬂashes, PVI was found to decrease hot ﬂash

symptoms, an effect perhaps mediated by the

observed changes in LH and follicle-stimulating

hormone (FSH) [81].

German women reporting earlier age at ﬁrst

intercourse (in all cases, postpubertal) had less

intense cortisol increases in response to a stan-

1344 Brody

J Sex Med 2010;7:1336–1361

dardized laboratory stressor (a nonsigniﬁcant

trend in the same direction was observed for

males), and faster recovery from the stressor [82].

In contrast, age at ﬁrst intercourse was unrelated

to the cortisol response to low-dose adrenocorti-

cotropic hormone (ACTH) stimulation. Although

shared genetic factors might inﬂuence both age at

ﬁrst intercourse and cortisol response to stress

(with its many important untoward psychological

and physiological sequelae), cortisol might impair

dopaminergic function, thereby impairing initia-

tion of and response to sexual activity [82].

PVI leads to increases in dopamine levels in the

nucleus accumbens (a region important in at least

attention to reward-related stimuli) of female

hamsters. The brain stimulation effect was absent

in females who were mounted as often by males

but did not manage to have intercourse because of

a hamster chastity belt: tape placed over their

vaginal openings [83]. The chastity belt still

allowed the females whatever beneﬁts are afforded

by being held and having stimulation of their

external genital region by the males mounting

them, but that was insufﬁcient to trigger the brain

stimulation effect provided by PVI. Thus, being

vaginally stimulated by a penis provides substan-

tially greater stimulation of the nucleus accumbens

than that provided by partner masturbation of the

external genital region.

The postorgasmic prolactin surge is associated

with reduction of sexual drive and with some

aspects of sexual satiety (whether directly through

inhibitory central dopaminergic and peripheral

processes, or as a process secondary to dopamin-

ergic effects) [84,85]. Dopaminergic signals from

the hypothalamus are a primary determinant of

prolactin release, and dopaminergic neurons

(including mesolimbic dopaminergic neurons) in

turn can be modulated by prolactin; a lengthier

discussion of these issues and a broader review of

studies of prolactin control of sexual drive is avail-

able elsewhere [84,85]. In an experimental exami-

nation of different sexual activities in the

laboratory by healthy adults, PVI caused both

sexes to manifest a postorgasmic prolactin increase

400% greater than that following masturbation

climax (adjusted for prolactin changes in a non-

sexual control condition) [86]. The results indicate

that PVI is not only more physiologically satisfy-

ing than masturbation, but the greater homeo-

static dopamine modulating effects might be

among the mechanisms involved in the psycho-

logical and physiological beneﬁts associated with

PVI rather than with other sexual activities [86],

and might also underlie differences between the

sexual satisfaction associated with various sexual

activities [11,12,87].

Biochemistry of Ejaculate

In a sample of men with erectile dysfunction,

greater frequency of masturbation was associated

with greater prostate speciﬁc antigen levels (mas-

turbation was also associated with prostate abnor-

malities, including a swollen or tender prostate)

[88].

A comparison of semen ejaculated by the same

men from masturbation and from PVI revealed

that the volume of seminal plasma, sperm count,

sperm motility, and percentage of morphologically

healthy sperm were all greater in the PVI samples

than in the masturbation samples [89]. In addition,

markers of the secretory function of the prostate

were signiﬁcantly better for the PVI samples,

which led the authors to infer that PVI was asso-

ciated with a better prostatic secretory function

than masturbation. Similarly, other researchers

[90] also used a within-subjects design and found

that compared with masturbatory samples of

ejaculate, men’s PVI samples had a larger semen

volume and increased concentrations and total

amounts of prostaglandin E and polyamines

(putrescine, spermidine, and spermine). Thus, PVI

involved better prostate function, larger semen

volume, better quality sperm, as well as elimina-

tion of more waste products.

In another study [91] that found that PVI

yielded far better sperm volume and sperm quality

than did masturbation (an effect which was most

dramatic in men with seminal deﬁciencies), the

authors noted that although the greater sperm

volume in the intercourse samples could be

explained by greater sexual stimulation leading to

“greater loading of the vas deferens prior to ejacu-

lation” (p 192), they could not explain the basis for

the difference in sperm morphology (quality),

which is “determined prior to spermatozoa reach-

ing the tail of the epididymis.” Thus, the organism

appears to anticipate that there will be PVI rather

than merely masturbation, and creates a higher

quality seminal product, among other physical

beneﬁts.

The experimental ﬁnding of better prostate

function being associated with PVI (rather than

masturbation) is consistent with epidemiological

studies linking PVI but not masturbation with

fewer disorders of the prostate. It is also consistent

with psychoanalytic and similar perspectives that

intercourse is more “disburdening” than other

Healthy Sex 1345

J Sex Med 2010;7:1336–1361

sexual behaviors. Although this latter concept was

largely meant to refer to the relief of tension, it

appears to apply to other physiological domains as

well. Rather than being just abstractions, some of

the differences between PVI and other sexual

behaviors can be measured in a test tube.

Prostate Cancer

Several studies have reported an association

between recalled frequency of ejaculation and

lower prostate cancer risk [92,93]. Unfortunately,

some of these studies vitiated the opportunity to

differentiate between protective and nonprotective

ejaculation conditions [94]. A British study found

no association of FSI with subsequent prostate

cancer risk, but did ﬁnd an increased prostate

cancer risk associated with higher masturbation

frequency in the 20s, 30s, and 40s, but the opposite

effect in the 50s. The authors noted that the latter

effect could be a result of, at least in part, reverse

causation [95].

A review of the literature on sexual risk factors

for prostate cancer found that cases had a lower

FSI from age 50 than did age-matched healthy

controls [96]. The cases also had a higher lifetime

prevalence of sexually transmitted disease, more

use of prostitutes, and a higher masturbation fre-

quency [96]. Similarly, another study found that

compared with controls, cases had a lower lifetime

FSI (men who had intercourse more than 3,000

times in their lives had half the risk of those that

did not), more homosexual partners (thus, not

PVI), and more use of prostitutes [97]. The exami-

nation of prostitute contact as a separate category

is important and commendable. It is not only

a proxy for possible exposure to sexually trans-

mitted disease (the usual interpretation), but a

potential indicator of dissociated sexuality by both

participants.

As noted in the section on biochemistry of

ejaculate, there are important differences between

sexual behaviors in markers of prostate function

and quantity of waste products, and these differ-

ences could conceivably impact prostate cancer

risk.

Breast Cancer

In a retrospective case-control study, both low PVI

frequency and greater condom (or withdrawal) use

were identiﬁed as risk factors for the development

of breast cancer [98]. Women with infrequent or

no PVI had thrice the breast cancer risk of the

controls (women who had more frequent PVI) in

the study. In addition, those women who did have

PVI but used a contraceptive method that

decreased pleasure by decreasing the contact of the

vagina with the penis, and decreased the woman’s

vaginal contact with semen (women who used

condoms or coitus interruptus), were at greater risk

for developing breast cancer than women who

used oral contraception or an intrauterine device

[98]. The interactive effect (PVI frequency and not

disrupting PVI by choosing condoms or with-

drawal) was noteworthy: those women who had

PVI (without the disruptive effects of condoms or

withdrawal before ejaculation) for at least 20 years

had one-tenth the breast cancer risk of women

who never had intercourse. Once again, condom

use (or withdrawal) is associated with the promo-

tion of a life-threatening condition.

In addition to that French study, an earlier study

from the United States found a similar association

[99,100]. Women whose men used condoms or

withdrawal (which generally involves the male

switching from intercourse to masturbation for

ejaculation), as well as women not engaging in

intercourse at all, had a breast cancer rate ﬁve

times higher than users of contraceptives that do

not reduce vaginal exposure to semen.

Greater lifetime number of sexual partners was

associated with decreased breast cancer risk [101],

and nuns were found to have very high rates of

breast cancer [102]. As noted in the Introduction,

a variety of methodological factors should be con-

sidered in evaluating risk-factor epidemiological

studies.

Immune Function and HIV

Although space constraints severely limit the pre-

sentation of the breadth of important evidence

related to HIV transmission risks that are gener-

ally ignored, a few key points and references to

review papers will be noted here. Of greatest

importance for the present exposition is the

extremely low risk of HIV transmission through

PVI for healthy persons of reproductive age, the

underestimation of the prevalence and risk associ-

ated with anal intercourse, and the underestima-

tion of the prevalence and risk associated with

punctures, especially those in medical and quasi-

medical settings in sub-Saharan Africa and some

other parts of the developing world [103–128].

Few studies of HIV transmission risks con-

ducted in sub-Saharan Africa have incorporated

adequate measures of unsafe punctures (and other

invasive procedures) in medical settings. Those

that have done so concurrently with measures of

sexual behavior have found that invasive medical

exposures were associated with greatly increased

1346 Brody

J Sex Med 2010;7:1336–1361

HIV incidence or prevalence, but measures of

sexual activity (nominally PVI, as well as lack of

condom use) were not associated with increased

HIV incidence or prevalence [103,114,129].

Mathematical models purported to support the

concept of PVI transmission have been shown to

be dependent on the use of assumptions grossly

inconsistent with reality [130]. The largest study

on mortality in American prostitutes found that

AIDS deaths occurred exclusively in those shown

or inferred to be injecting drug users [54]. In a

large representative American sample [131], con-

trolling for history of homosexual contact and

injection drug use revealed that for non-Hispanic

black men, prevalent HIV infection was not posi-

tively associated with lifetime number of sex part-

ners. The focus on black men is key not only

because they are the most severely affected

demographic (sex by race) group in the United

States, but also because their base rate of HIV

infection is high enough to obtain stable statistical

associations.

Perhaps most importantly, when the vagaries

and potential confounds of risk-factor epidemiol-

ogy are bypassed, laboratory challenge of tissue

under optimal conditions revealed that vaginal and

cervical tissue could not become infected by expo-

sure to HIV [132–134], but rectal tissue was

readily infected under the same conditions

[132,133] (in the cited studies, tissues used

approximated those in natural conditions—none

were chemically abraded to the point of inchoate

disintegration, and viral exposure was restricted to

surfaces relevant to normal organs, rather than

allowing leakage from the sliced edges of the biop-

sies). As one research group noted: “Our data show

that urogenital epithelial cells cannot be infected

with NSI or SI phenotypic isolates of HIV-1” (p.

1208) [132]; this bench science observation was

echoed by another research group: “HIV particles

are not transmitted across the human vaginal

mucosa and Langerhans cells do not increase HIV

transmission” (p. 1263) [134].

In a study that examined immune function in

both female prostitutes and male to female trans-

sexuals (all HIV negative, matched for age, dura-

tion of prostitution, number of clients, and previous

use of antibiotics), receptive anal intercourse was

found to be associated with signiﬁcantly decreased

delayed-type hypersensitivity and CD4/CD8 ratios

[135]. The authors concluded that receptive anal

intercourse results in immunological abnormali-

ties, and posited that the process is a result of rectal

exposure to seminal alloantigens [135]. Similarly,

rectal insemination (but not saline introduced into

the rectum) of male rabbits led to immune suppres-

sion, including the development of immune com-

plexes, sperm antibodies, and antibodies to

peripheral blood lymphocyte antigens; additional

immune effects including impaired humoral

immune response to T lymphocyte-dependent

antigens, keyhole limpet hemocyanin, and sheep

red blood cells [136]. The results provide further

evidence that receptive anal intercourse is immune

suppressive, even in the absence of pathogens.

In contrast, PVI is associated with HIV-relevant

immune beneﬁts that were obliterated by condom

use [137]. The authors concluded: “Unprotected

sexual intercourse might result in alloimmuniza-

tion stimulated by HLA antigens in seminal or

cervicovaginal ﬂuid. Mucosal alloimmunization

may reduce infection by HIV-1” (p. 518).

Life Expectancy

Several longitudinal studies have found that a

greater FSI predicts a longer life expectancy, but

unfortunately most of these studies have not

explicitly contrasted FSI with frequency of other

sexual behaviors.

In a 25-year follow-up study, it was found that

greater FSI predicted a lower annual death rate in

men, whereas enjoyment of intercourse predicted

lower mortality among women [138]. Similarly,

greater FSI was associated with lower age-adjusted

death rates in a 10-year study of British men that

examined and excluded several possible confound-

ing variables [139]. Compared with men reporting

an FSI of at least twice weekly, men reporting an

FSI of less than monthly (as well as men who

declined to answer the question) had twice the

death rate. The beneﬁts associated with greater

FSI were most apparent for reduced coronary

heart disease mortality, which is the major cause of

death in most countries of the First World. The

researchers controlled for baseline coronary heart

disease, as well as for social class, smoking, and

blood pressure, thereby limiting to some degree

the inﬂuence of reverse causality.

International comparisons suggest that national

FSI estimates (as derived from surveys) are

strongly associated with measures of national

development, including life expectancy [140]. Of

course, such ecological-level comparisons are

subject not only to the usual epidemiological

caveats, but to the risk of aggregation bias as well.

According to U.S. government estimates [141]

men using sildenaﬁl are considerably less likely to

die of a myocardial infarction the day that they use

Healthy Sex 1347

J Sex Med 2010;7:1336–1361

the medication than would be expected from the

population base rate of men that age dying from

that major cause of death. One might infer that

most of the men used the medication for inter-

course rather than for masturbation, but this infor-

mation was not provided. The results are not

adjusted for some potentially important factors

(including how healthy the men were the preced-

ing day), and both intercourse itself and perhaps a

direct cardioprotective effect of the medication

might have some life-sustaining beneﬁt. In con-

trast, it has been noted that during general physical

exertion, men are 10 times more likely to have a

myocardial infarction as when at rest [142].

Female crickets that mated repeatedly lived

32% longer than crickets that mated only once.

Because the experimenters controlled the lifestyle

of their subjects, the males provided only copula-

tion (and sperm and seminal ﬂuid) to the females,

but not food or protection, thereby demonstrating

that either the mating process itself or chemical

components of the semen extended female life

[143]. Higher on the phylogenetic scale, male rats

who (for apparently genetic reasons) had a rela-

tively high FSI lived 13% longer than those with a

low or zero FSI [144]. In the latter study, admin-

istration of the Monoamine oxidase B (MAO-B)

inhibitor deprenyl (also known as selegiline, it

slows the degradation of dopamine and may have

neuroprotective effects) increased FSI and the life

span of the rats.

Tabular Summaries

Tabular summaries of the main studies reviewed

herein are provided (Table 1 for psychological and

psychophysiological, and Table 2 for physiological

health aspects of different sexual behaviors).

However, the Tables are not a substitute for the

narrative expositions in the manuscript. The

health beneﬁts in the Tables are all worded such

that a “+” in the last column indicates more health

beneﬁts (including decreased health risks); a “-”in

the last column indicates less health beneﬁts

(including increased health risks); a “0” in the last

column indicates nonsigniﬁcant effects; a combi-

nation of “0” and “-”or“+” indicates mixed results

(often in different analyses); and the inclusion of a

“?” indicates some mixed ambiguous results.

Discussion

The present overview indicates that there are

many psychological and physiological health ben-

eﬁts associated with one speciﬁc sexual activity. It

is speciﬁcally PVI, competently performed and

sensitively experienced, that is associated with (as

indicated by the correlational research designs),

and produces (as indicated by the experimental

research designs) aspects of better mental and

physical health. This is not the case for other

sexual behaviors (masturbation and anal inter-

course are associated with poorer health indices,

effects not attributable simply to lack of PVI). It is

also not the case when PVI is done poorly, psycho-

logically dissociated, or impaired.

The multimethod evidence presented here that

speciﬁcally PVI and the orgasm it produces (rather

than other sexual behaviors and responses) is asso-

ciated with indices of better psychological and

physiological health has several implications.

Before addressing those implications, methodo-

logical issues and possible mechanisms for the

observed effects are discussed.

Experimental, Correlational, and Quasi-Experimental

Research Designs

There were a few experimental studies reviewed

herein, and the potentially higher standard of evi-

dence that they can provide leads to some of the

experimental ﬁndings being noted here again.

In the randomized trial of coitus (vs. no coitus)

for the treatment of menopausal hot ﬂashes, PVI

decreased hot ﬂash symptoms, an effect perhaps

mediated by the observed changes in LH and FSH

[81]. In addition to the speciﬁc health outcome,

the ﬁndings offer support for PVI leading to better

hormonal regulation (and the secondary beneﬁts

thereof).

The randomized controlled trial of high dose

ascorbic acid [69] indicated that better health (in

the form of better nutrition) can lead to greater

frequency of speciﬁcally PVI but not other part-

nered or solitary sexual behaviors (ascorbic acid

also improved mood, so it is unclear if mood

enhancement was part of the causal pathway).

Thus, in addition to effects of speciﬁcally PVI

leading to better health, better health can lead to

greater frequency of speciﬁcally PVI, and this can

be the case even in nominally healthy persons

(rather than only as a consequence of identiﬁed

morbidity). As noted in the Introduction, there can

be bi-directional causality, as in vicious or virtuous

circles of health.

In the laboratory, PVI was shown to produce

greater physiological exercise value than mastur-

bation or masturbation by a partner [74].

In the laboratory, PVI caused both sexes to

manifest a postorgasmic prolactin increase 400%

1348 Brody

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Table 1 Psychological and psychophysiological health aspects of different sexual behaviors

Health aspect Reference Design Participants DV Results

Mental health satisfaction [11] Correlational

(multivariate)

M, W Satisfaction with one’s mental health PVI frequency: +

Masturbation frequency: -

Noncoital sex frequencies: 0

[12] Correlational W Satisfaction with one’s mental health Vaginal orgasm (vs. clitoral orgasm) ever: +

Relationship quality [15] Correlational W Perceived Relationship Quality Components (PRQC)

Inventory dimensions: Satisfaction, Intimacy, Trust,

Passion, and Love

PVI frequency: +

Noncoital sex frequencies: 0/-

Masturbation frequency: -(Love)

PVI orgasmic frequency: +

[16] Correlational W Marital and sexual satisfaction PVI frequency: +

Cunnilingus frequency: 0

Masturbating male to orgasm: -

[17] Correlational W (Kinsey data) Marital happiness PVI orgasmic frequency: +

[11] Correlational

(multivariate)

M Relationship satisfaction PVI frequency: +

Masturbation frequency: -

Oral sex frequency: -

Anal sex frequency: -

[11] Correlational

(multivariate)

W Relationship satisfaction PVI frequency: +

Masturbation frequency: -

Emotional awareness and

integration

[21] Correlational W Less alexithymia (Toronto Alexithymia Scale-20) PVI frequency: +

Masturbation frequency: 0

Noncoital sex frequencies: 0

Less psychological immaturity

(less use of immature

psychological defense

mechanisms)

[24] Correlational W Less use of immature psychological defense

mechanisms (Defense Style Questionnaire-40)

Vaginal orgasm: +

Clitoral orgasm: 0/-

Clitoral orgasm during PVI: 0/-

[25] Correlational M +W Less use of immature psychological defense

mechanisms (Defense Style Questionnaire-40)

PVI frequency without condoms: +

PVI frequency with condoms: -

Masturbation orgasm: -

Clitoral orgasm during PVI (W): 0/-

Vaginal orgasm: +

[31] Correlational W Less use of immature psychological defense

mechanisms (Defense Style Questionnaire-40)

Clitoral orgasm during PVI: -

Vaginal orgasm: +

Masturbation orgasm: -

Anal sex: -

Vibrator use: -

Less depression and less

suicide attempts

[34] Correlational M Lower MMPI depression scores Masturbation ejaculations: -

Partnered sex ejaculations: 0

[35] Correlational W Lower Beck Depression Inventory scores Masturbation: -

Desire for masturbation: -

Desire for partnered sexual activity: 0

[36] Correlational W Less likelihood of lifetime major depressive disorder

(Structured Clinical Interview for the DSM-IV)

Masturbation frequency: -

[38] Correlational W Lower Beck Depression Inventory scores and less

suicide attempts

PVI without condoms: +

PVI with condoms: -

[33] Correlational

(cross-sectional

and longitudinal)

W Lower Hopkins Symptom Checklist depression

scores

Condom use: -

[43] Correlational M +W Less suicide contemplation

Less deliberate self-harm

Homosexual (vs. Heterosexual): -

Homosexual (vs. Heterosexual; M): -

[41] Correlational M +W Less mood disorders Homosexual (vs. Heterosexual): -

Healthy Sex 1349

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Table 1 Continued

Health aspect Reference Design Participants DV Results

Happiness [37] Correlational M +W Self-rated happiness Masturbation: -

Less psychoticism and

neuroticism

[47] Correlational

(Twin study)

M+W Lower Eysenck Personality Questionnaire (EPQ-R)

Neuroticism and Psychoticism scores

Homosexual and bisexual (vs. Heterosexual): -

(Note: Effects were found to be associated with genetic

but not environmental inﬂuences)

Less schizophrenia [48] Correlational M +W Less likelihood of schizophrenia diagnosis PVI frequency: +

Masturbation frequency: 0

[49] Correlational M Less likelihood of schizophrenia diagnosis Masturbation frequency: -

[50] Correlational W Less likelihood of schizophrenia diagnosis PVI orgasm: +

Less anorexia nervosa [50] Correlational W Less likelihood of anorexia nervosa diagnosis PVI orgasm: +

Less neurotic disorders [50] Correlational W Less likelihood of neurotic disorder diagnosis PVI orgasm: +

[51] Correlational W Less likelihood of neurotic disorder diagnosis PVI orgasm: +

Clitoral orgasm: 0

Less prostitution (related to

various psychological

disorders; [53])

[52] Correlational W Less likelihood of prostitution PVI orgasm: +

Improved erectile function [55] Clinical trial of

intracavernosal

injection (not blind)

M Effect of restoration of erectile function PVI frequency: +

Masturbation frequency: -

General psychiatric symptomatology reduction: +

Awareness and integration of

vaginal sensations

[22] Mixed correlational

and experimental

W Concordance of vaginal pulse amplitude and

subjective sexual arousal

PVI orgasmic consistency: +

Masturbation orgasmic consistency: 0

Noncoital orgasmic consistency: 0

[23] Mixed correlational

and experimental

W Concordance of vaginal pulse amplitude and

subjective sexual arousal

PVI orgasmic consistency: +

Masturbation orgasmic consistency: 0

Noncoital orgasmic consistency: 0

Reduced pain: Prostatodynia [56] Correlational M Reduced pain and voiding symptoms PVI: +

Masturbation: -

Reduced pain: Experimental [57,58] Experimental W Pain levels Vaginal >> Clitoral

Note: These tables are a summary, but not a substitute for the narrative expositions in the manuscript. The health beneﬁts are all worded such that a “+” in the last column indicates more health beneﬁts (including decreased health risks), a “-”

in the last column indicates less health beneﬁts (including increased health risks), a “0” in the last column indicates nonsigniﬁcant effects, a combination of “0” and “-”or“+” indicates mixed results (often in different analyses), and the inclusion

of a “?” indicates some mixed ambiguous results.

M=men; W =women; DV =dependent variable; PVI =penile-vaginal intercourse; MMPI =Minnesota Multiphasic Personality Inventory.

1350 Brody

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Table 2 Physiological health aspects of different sexual behaviors

Health aspect Reference Design Participants DV Results

Life expectancy [138] Correlational: Longitudinal (25 years) M +W Lower annual death rate PVI frequency: +(M)

Enjoyment of PVI: +(W)

[139] Correlational: Longitudinal (10 years) M Lower annual death rate PVI frequency: +

[140] Correlational: International ecological M +W Life expectancy (national) PVI frequency: +

[143] Experimental Crickets (female) Life expectancy PVI frequency: +

[144] Mixed correlational and experimental

(deprenyl trial)

Rats (male) Life expectancy PVI frequency: +

Vaginal function [60] Review W Vaginal tone, oxygenation, blood ﬂow PVI: +

Condoms: -(oxygenation, blood ﬂow effects?)

Less functional musculoskeletal

disturbance

[61] Correlational W Anatomically normal gait Vaginal orgasm history: +

Clitoral orgasm history: 0

Less body fatness [62] Correlational M +W Slimmer waist and/or hip circumference PVI frequency: +

Masturbation frequency: -

Noncoital sex frequency: 0/+

[63] Correlational Rats (Male) Nonobese vs. obese PVI frequency: +

Cunnilingus: 0

Nutritional enhancement effects [69] Experimental (RCT) M +W Effect of 14 days 3,000 mg/day ascorbic acid vs.

placebo

PVI frequency: +(effect attributable to W)

Masturbation frequency: 0

Noncoital sex frequency: 0

Better heart rate variability [71] Correlational M +W Heart rate variability (resting) PVI frequency: +

Masturbation frequency: 0

Noncoital sex frequency: 0

Subjective importance of PVI: +

[70] Correlational M +W Heart rate variability (resting) PVI frequency: +

Masturbation frequency: 0

Noncoital sex frequency: 0

Subjective importance of PVI: +

Lower resting blood pressure [71] Correlational M +W Lower diastolic blood pressure (resting) PVI frequency: +

Masturbation frequency: 0

Noncoital sex frequency: 0

Note: ns results for diastolic blood pressure in [70]

[72] Correlational M Less likelihood of hypertension (newly diagnosed

and untreated)

PVI frequency: +

Less blood pressure reactivity to

acute stress

[73] Mixed (correlational with sexual behavior,

experimental stressor)

M+W Less blood pressure increase before and during

stress, and faster recovery after stress

PVI (past 2 weeks): +

Masturbation (frequency past 2 weeks): 0/-

Pattern: PVI only >PVI +days with only other sexual

activities ⱖonly other sexual activities

Better exercise value [74] Experimental M Better oxygen uptake, and blood pressure and heart

rate stimulation

PVI >masturbation

Less pre-eclampsia risk (3 studies) [75-77] Correlational W Less pre-eclampsia risk Condoms: -

PVI frequency: +

Fellatio: +

Improved testosterone levels [78] Experimental/Clinical M Restoration of normal testosterone level with various

nonhormonal treatments of erectile dysfunction

PVI frequency: +

Decreased menopausal hot ﬂashes [81] Experimental (randomized nonblind trial of

coitus vs. no coitus)

W Effect on menopausal hot ﬂashes and LH and FSH

normalization

PVI: +

Less intense cortisol response to

stress

[82] Mixed (correlational with sexual behavior,

experimental stressor)

M+W Less intense cortisol response to stressor Earlier age at ﬁrst PVI: +(W, ns trend for M)

Increases in dopamine levels in the

nucleus accumbens

[83] Experimental Rats (Female) Increases in dopamine levels in the nucleus

accumbens

PVI: +

Mounting/cuddling/external stimulation without PVI: 0

Greater prolactin increase following

orgasm

[86] Experimental M +W Greater prolactin increase following orgasm PVI >> masturbation

Healthy Sex 1351

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Table 2 Continued

Health aspect Reference Design Participants DV Results

Better sperm quality [89] Experimental M Volume of seminal plasma, sperm count, sperm

motility, and percentage of morphologically

healthy sperm

PVI >masturbation

[91] Experimental M Greater sperm volume and quality PVI >masturbation

Better prostatic secretory function [89] Experimental M Better prostatic secretory function PVI >masturbation

Lower prostate speciﬁc antigen

levels and fewer prostate

abnormalities

[88] Correlational M (with erectile

dysfunction)

Lower prostate speciﬁc antigen levels and fewer

prostate abnormalities

Masturbation: -

Better elimination of waste

products

[90] Experimental M Increased concentrations and total amounts of

prostaglandin E and polyamines (putrescine,

spermidine and spermine)

PVI >masturbation

Less prostate cancer risk [95] Correlational M Less prostate cancer risk PVI frequency: 0

Masturbation frequency: ?

[96] Correlational M Less prostate cancer risk PVI frequency: +

Masturbation frequency: -

Prostitute use: -

[97] Correlational M Less prostate cancer risk PVI frequency: +

Homosexual partners: -

Prostitute use: -

Less breast cancer risk [98] Correlational W Less breast cancer risk PVI frequency: +

Condoms: -

Coitus interruptus: -

[99,100] Correlational W Less breast cancer risk PVI frequency: +

Condoms: -

Coitus interruptus: -

[101] Correlational W Less breast cancer risk Lifetime number of sexual partners: +

Tissue could not become infected

by exposure to HIV (3 studies)

[132–134] Experimental (tissue challenge without

excess damage to the tissue)

W (biopsies) Tissue could not become infected by exposure to

large quantities of HIV

Vaginal: +

Cervical: +

Rectal: -

Note: See the relevant section for important

extensive references to other studies with similar

implications

Less impairment of immune

function

[135] Correlational W +MTF

Transsexuals

Delayed-type hypersensitivity (DTH) and CD4/CD8

ratios

Receptive anal intercourse: -

[136] Experimental Rabbits (Male) Less immune complexes, sperm antibodies, and

antibodies to peripheral blood lymphocyte

antigens; additional immune effects including

impaired humoral immune response to T

lymphocyte-dependent antigens, keyhole limpet

hemocyanin, and sheep red blood cells

Rectal insemination (vs. saline introduced into the

rectum): -

Immune beneﬁts including possible

resistance to HIV-1 infection

[137] Correlational M +W resistance to HIV-1 infection by challenging

activated CD4-positive T cells with CCR5-binding

and CXCR4-binding HIV-1 strains

PVI: +

Condoms for PVI: -

(including increased health risks), a “0” in the last column indicates nonsigniﬁcant effects, a combination of “0” and “-”or“+” indicates mixed results (often in different analyses), and the inclusion of a “?” indicates some mixed ambiguous results.

M=men; W =women; DV =dependent variable; PVI =penile-vaginal intercourse; FSH =follicle-stimulating hormone; LH =luteinizing hormone; RCT =randomized controlled trial; MTF =male-to-female; ns =nonsigniﬁcant.

1352 Brody

J Sex Med 2010;7:1336–1361

greater than following masturbation climax

(adjusted for a control condition) [86]. The greater

homeostatic dopamine modulating effects might

be among the mechanisms involved in the psycho-

logical and physiological beneﬁts associated with

PVI rather than with any other sexual activities

[86].

In multiple within-subjects studies [89–91]

comparing semen samples produced by PVI and

by masturbation, PVI led to indicators of better

prostate function, better quality sperm, better

semen volume, and elimination of more waste

products. Although not a health outcome per se,

this has implications not only for prostate health,

but quite possibly for other beneﬁcial conse-

quences of more effective elimination of waste

products.

Female crickets that were allowed to mate

repeatedly lived 32% longer than crickets that

mated only once. Experimental controls allowed

the inference that either the mating process itself

or chemical components of semen extend female

life [143]. Although the research subjects are a

different phylum than the readers of this review,

the ﬁnding is consistent with the human life

expectancy epidemiological results and with the

human PVI seminal exposure ﬁndings (related to

better immune function, better vaginal blood ﬂow,

and less depression) reviewed herein.

The majority of studies in this review used cor-

relational (or risk-factor epidemiological) research

designs (this problem is difﬁcult to overcome,

given the nature of some of the variables to which

research subjects cannot be randomly assigned,

such as immature psychological defense mecha-

nisms). In such research designs, there is always

the possibility that unmeasured third variables

inﬂuence both the predictor variable and the

outcome of interest (e.g., see below for a discus-

sion of possible heritable factors).

Possible Mechanisms

The present review implied some mechanisms that

might, at various explanatory levels, clarify some of

the bases for the health beneﬁts associated with

speciﬁcally PVI. In addition to those processes

noted in the text above, a few such mechanisms

will now be brieﬂy described. Although these pos-

sible mechanisms are examined separately, it is rea-

sonable to conjecture that various mechanisms

interact. For example, psychological outlook can

modify some effects of physiological and pharma-

cological stimuli. The psychological outlook itself

would be signiﬁcantly inﬂuenced by genes (as ﬁl-

tered by natural and sexual selection, but also

inﬂuenced by individual differences in the load of

harmful mutations [145]) interacting with devel-

opmental inﬂuences (including those which

support or impair psychosexual development), and

would involve various neurophysiological pro-

cesses (which themselves are conditioned to some

degree by experience).

Possible Mechanisms: Evolutionary Issues

First, there is the distal evolutionary theoretical

level: out of the universe of possible sexual activi-

ties, there is only one that is directly relevant to

gene propagation. Evolutionary pressures strongly

reward behaviors and mutations even slightly asso-

ciated with increased likelihood of gene propaga-

tion. The difference between PVI and other sexual

behaviors is not slight. The mechanisms by which

such evolutionarily mandated rewards might

operate range from direct physiological mecha-

nisms (responding favorably to PVI but neutrally

or unfavorably to other sexual activities) to mecha-

nisms secondary to the evolutionary behavioral

“success” of speciﬁcally PVI being rewarded by

better physical and mental health (and perhaps the

evolutionary behavioral failure of other sexual

activities such as masturbation being punished by

poorer physical and mental health). In addition to

whatever skills and characteristics might be

required to obtain a sexual partner, there might be

additional skills and characteristics required for

PVI that exceed those required for other partnered

sexual activities. Evolution might also reward

engaging in the one potentially reproductive

behavior with various psychological (including a

sense of accomplishment and/or intimacy, for

some) and physiological beneﬁts, and provide

incremental rewards when there is no impediment

to ejaculating into the vagina (i.e., without

condoms).

Possible Mechanisms: Neurophysiological Issues

Second, at the neurophysiological level, there are

differences between various sexual activities

and/or areas of stimulation. As noted earlier, for

both sexes, the magnitude of prolactin release fol-

lowing PVI orgasm is 400% greater than follow-

ing masturbation orgasm (adjusted for responses

to a control condition), and there are likely impor-

tant psychological and psychophysiological impli-

cations of this dopaminergically relevant process

[86].

Lesions to the medial preoptic hypothalamic

area of adult male rhesus monkeys led to an elimi-

nation of PVI, but no change in general social

Healthy Sex 1353

J Sex Med 2010;7:1336–1361

behavior or frequency of masturbation [146],

implying that PVI is a neurophysiologically more

complex phenomenon than masturbation.

The activation of peripheral afferents also

differs between some sexual activities. The pelvic

nerve conducts sensory information from the

vagina and regions of the cervix to the spinal cord

for transmission to the brain, whereas the puden-

dal nerve carries sensory information from the cli-

toris and external perigenital skin to the spinal

cord for transmission to the brain [147]. The

hypogastric nerve carries sensory information

from the uterus and some regions of the cervix to

the spinal cord for transmission to the brain.

These nerves enter the spinal cord in different

places, and have other important differences that

might relate to the quality of the signal and other

secondary effects of information that the nerves

carry [147]. Vaginal–cervical (not clitoral) stimula-

tion results in sensory information being conveyed

by the vagus nerve to the brain, bypassing the

spinal cord (and allowing even women with com-

plete spinal cord transection to orgasm from

vaginal–cervical stimulation, albeit not clitoral

stimulation [148]). This vagus connection is espe-

cially interesting in light of the aforementioned

studies reporting that vagus-mediated greater

resting heart rate variability and lesser blood pres-

sure stress reactivity (as well as some personality

processes that might be related to greater vagus

activity) are associated with PVI but not other

sexual activity frequencies [70,71,73]. Among

other possibilities, there may be a “tuning” of

autonomic functioning by habitual behaviors

[149], and such tuning might inﬂuence not only

resting autonomic tone, but also the response to

subsequent sexual activity.

Transection of the female rat pelvic nerve

reduced vaginocervical-stimulation induced Fos

immunoreactivity in the medial preoptic area, bed

nucleus of the stria terminalis, ventromedial hypo-

thalamus, and medial amygdala. In contrast,

transection of the clitorally linked pudendal nerve

had no such effect [150]. This and other studies

suggest that (vaginal) pelvic nerve but not (clitoral)

pudendal nerve activity leads to crucial brain

effects from PVI (including possibly facilitation of

readiness for future PVI).

The hormone oxytocin has several functions,

and appears to have a role in promoting pair-

bonding. When oxytocin is injected into female

laboratory animals, they become more sexually

receptive [147]. This is the case not only in intact

animals, but also in those whose (clitorally rel-

evant) pudendal nerve has been severed. However,

if the (vaginally relevant) pelvic nerve is cut, oxy-

tocin no longer increases sexual receptivity [147].

Therefore, it is the nerve carrying sensation

from PVI, and not the nerve carrying signals from

external clitoral stimulation, that is required

for the hormone oxytocin to manifest some of

its functions.

Although there are sexual behavior differences

in postorgasmic prolactin effects (and resting heart

rate variability and blood pressure reactivity, sug-

gesting Vagus nerve effects) for both sexes, the

peripheral genital nerve structures differentiating

intercourse from other sexual activities are not as

obvious for males as for females. However, besides

differentiation at the level of speciﬁc nerves, for

both sexes, there is also the issue of patterns of

interactive stimulation that can differentiate

various sexual behaviors. A few studies have pro-

vided some technical details regarding genital pul-

satile communication. Penile thrusting in the

vagina and against the cervix results in the vaginal

muscles gripping the lower part of the penis

[151,152], potentially leading to not only identiﬁ-

cation of the process being PVI as distinguished

from other sexual behaviors (including stimulation

with nongenital objects), but also a virtuous circle

of genital-to-genital response.

As suggested to varying degrees in various

studies above [25,38,60,137,143], there is also

the possibility that the absorption of semen by the

vagina and absorption of vaginal secretions by the

penis activate psychological and physiological

health-supporting pathways.

There are likely other physiological (and

perhaps implicit psychological) mechanisms by

which the organism differentiates PVI from other

sexual behaviors (to induce better health). One

need only pause to reﬂect on the evolutionary

value of differentiating perhaps one million differ-

ent colors as compared with the evolutionary value

of mechanisms for differentiating between activi-

ties that could or could not perpetuate the “selﬁsh

gene” [153].

Possible Mechanisms: Psychosexual Issues

Third, there are the psychosexual developmental

issues. As conjectured by Freud, problems in psy-

chosexual development can produce chronological

adults with psychological (including psychophysi-

ological) problems, and associated impairment of

the ability to appreciate fully PVI. Several studies

described herein, including those on alexithymia

and on immature psychological defense mecha-

1354 Brody

J Sex Med 2010;7:1336–1361

nisms [21,24,25,31], speak to those issues. The

results of those studies could generally be under-

stood as an example of poorer health leading to

avoidance of or impairment of speciﬁcally PVI

(including choosing to use condoms for PVI, lack

of vaginal orgasm, or choosing other sexual activi-

ties in lieu of PVI), but one cannot not rule out

that there might be a role for impairment or avoid-

ance of PVI leading to increased use of immature

defense mechanisms.

Although the concept of impaired psychosexual

development leading to avoidance of speciﬁcally

PVI frequency or response might seem arcane for

some readers, some basic aspects of the process can

be operationalized in an obvious manner. For

example, in a laboratory study [154], adult male

hamsters underwent a single-trial learned aversion

to vaginal secretion. Subsequently, they had a

lower PVI frequency than did the control group.

Although the hamsters with the learned aversion

to PVI also had a lower frequency of grooming

their own genitals, they did not differ in the

amount of time they spent licking vaginas [154].

Thus, the unpleasant early experience did not even

lead to avoidance of vaginal secretions, but to

avoidance of the deeper function of PVI.

Engaging in masturbation or even partnered

sexual behavior in the absence of PVI on some

days appears to detract from the psychological [11]

and physiological [73] beneﬁts associated with

having PVI on other days. Among the possible

mechanisms for this is a psychological variant on

the autonomic tuning process [149] described

above: PVI might be approached in essentially the

same spirit (including less relatedness, which is

manifestly the case for masturbation) as the other

sexual activities, leading to less psychological and

physiological beneﬁt from PVI. Another possibil-

ity [73] is that PVI is being avoided on some but

not all occasions (by substituting other sexual

activities), which might be because of a subtler

psychosexual dysregulation than complete avoid-

ance of PVI.

Possible Mechanisms: Genetic Factors

Fourth, genetic factors could conceivably produce

both greater FSI (but not greater frequency of

other sexual behaviors) and better physical and

mental health. Suggestive, if weak, support for

this hypothesis might be gleaned from the ﬁnding

that male rats who—for apparently genetic

reasons—had a relatively high FSI lived 13%

longer than those with a low or zero FSI [144].

Studies of women’s intercourse orgasm consis-

tency (unfortunately, not specifying vaginal

orgasm in any of the three studies) reported a

heritability of 31–34% for intercourse orgasm

consistency [155,156] (and 45–51% heritability

estimates for masturbation orgasmic consistency),

as well as signiﬁcant associations with extraversion,

being open to new experience, and less neuroti-

cism [157]. These dimensions of personality also

have a signiﬁcant heritability. The association of

coital orgasm consistency with less neuroticism

would be consistent [158] with the ﬁndings of

immature defense mechanisms being associated

with lesser vaginal orgasm consistency [24,25,31].

When feasible, future research on sexual behav-

ior and sexual medicine might incorporate sophis-

ticated quasi-experimental designs that consider

the effect of heritable factors. When one such

behavior genetic quasi-experimental design was

used, it was revealed that earlier age at ﬁrst inter-

course is associated with less (rather than as usually

assumed, more) subsequent conduct disorder in

American samples [159].

Implications for Clinical Assessment,Treatment,

Research, and Sex Education

Clinicians and researchers need to be speciﬁc in

examining various sexual behaviors (including

details of how PVI might have been modiﬁed from

its pure form, such as condom use or clitoral mas-

turbation during PVI; studies noted herein found

these practices to be associated with poorer func-

tioning than undisturbed PVI). Despite the scien-

tiﬁc and clinical importance of being speciﬁc

regarding the differences between speciﬁc sexual

behaviors, some of the most commonly used

research and clinical measures of sexual function

explicitly obscure the differences between various

sexual behaviors, thereby limiting their utility and

ability to help patients and scientiﬁc inquiry. For

example, Female Sexual Function Index [160]

questions refer to “sexual activity or intercourse,”

thereby losing the essential differentiation (the

questions that specify “vaginal penetration” are

those dealing with pain). The International Index

of Erectile Function [161] includes many ques-

tions with the nonspeciﬁc “sexual activity includes

intercourse, caressing, foreplay & masturbation,”

and some with “sexual intercourse is deﬁned as

sexual penetration of your partner” (which could

involve anal intercourse, and perhaps even broader

interpretations might be made by some people).

More speciﬁc questionnaires specifying more spe-

ciﬁc sexual behaviors [24] would be far more infor-

mative, and allow sexual medicine to advance.

Healthy Sex 1355

J Sex Med 2010;7:1336–1361

In addition, sex education should begin to be

honest regarding physiological and psychological

health differences between speciﬁc sexual behav-

iors. In a recent large representative survey of

Czech women, vaginally orgasmic women were

signiﬁcantly more likely than vaginally anorgasmic

women to report having being told in childhood or

adolescence that the vagina was an important zone

for inducing female orgasm [162].

Treatment (including primary prevention)

should be supportive of PVI and the orgasm it

produces, and not assume that behavioral treat-

ment of sexual dysfunction must involve mastur-

bation as part of the process. There are effective

PVI-based treatments for premature ejaculation

[163] and for female orgasmic dysfunction [164]. It

has been noted that for some women, repeated

orgasm from clitoral stimulation can interfere with

the development of pathways leading to vaginal

orgasm [165,166]. In a recent large representative

survey of Czech women, risk of female sexual

arousal disorder with distress (albeit not without

distress) was much lower for women who had a

history of vaginal orgasm [167]. The concept of

sexual dysfunction merits both broadening and

more speciﬁcity (e.g., lack of vaginal orgasm [31])

in light of the research described herein.

Among the factors shown to be associated with

greater likelihood of women’s orgasm with a

partner is duration of PVI, but not duration of

foreplay (in contrast to the assumptions of many

practitioners) [162,168]. Future studies might

examine in greater detail which physiological and

psychological factors lead to people avoiding (in

behavior or full feeling and response) the key evo-

lutionarily driven sexual behavior, including

choosing to substitute something else for one set

of genitals in lieu of genital–genital (penile–

vaginal) intercourse.

There might also be implications for future

research involving pharmacotherapy. Women’s

positive response to phosphodiesterase inhibitor

treatment for sexual dysfunction was better in

women with “stable and/or happy relationships”

(p. 156), and nonresponse was more common in

the “presence of psychological co-morbidities” (p.

156) [169]. Studies might examine the degree to

which phosphodiesterase inhibitor beneﬁt is more

likely in women [170] who are more aware of their

vaginal response (especially those with a history of

vaginal orgasm).

Some studies of risk factors for sexual dysfunc-

tion might suggest future studies on the possible

inﬂuence of better sexual function on the preven-

tion of the “risk factors.” For example, a global

measure of women’s sexual dysfunction found mul-

tivariate associations with lower high density lipo-

protein cholesterol, and higher low density

lipoprotein cholesterol, triglycerides, body mass

index, and age [171]. Given that more favorable

lipid proﬁles may be associated with more mature

emotion expression [172,173], and that speciﬁcally

PVI frequency and response is associated with both

slimness [62] and better emotional functioning

[11,12,21,24,25], future research might examine

the possibility that unfavorable lipid proﬁles might

be secondary to sexual behavior factors. Various

studies have indicated associations between depres-

sion, cardiovascular disease or risk, and sexual dys-

function (especially erectile dysfunction). In

addition to such obvious pathways as cardiovascular

disease leading to erectile dysfunction leading to

depression, other pathways are also likely [174].

Conclusion

Based upon a broad range of methods, samples,

and measures, the research ﬁndings are remark-

ably consistent in demonstrating that one sexual

activity (PVI and the orgasmic response to it) is

associated with, and in some cases, causes pro-

cesses associated with better psychological and

physical functioning. Other sexual behaviors

(including when PVI is impaired, as with condoms

or distraction away from the penile–vaginal sensa-

tions) are unassociated, or in some cases (such

as masturbation and anal intercourse) inversely

associated with better psychological and physical

functioning.

Sexual medicine, sex education, sex therapy, and

sex research should disseminate details of the

health beneﬁts of speciﬁcally PVI, and also

become much more speciﬁc in their respective

assessment and intervention practices.

Corresponding Author: Stuart Brody, PhD, School of

Social Sciences, University of the West of Scotland,

High Street, Paisley PA1 2BE, UK. Tel: 44 141 849

4020; Fax: 44 141 8483891; E-mail: stuartbrody@

hotmail.com

Conﬂict of Interest: None. However, Dr. Brody discloses

that he was or is a consultant for Bayer Schering.

Statement of Authorship

Category 1

(a) Conception and Design

Stuart Brody

1356 Brody

J Sex Med 2010;7:1336–1361

(b) Acquisition of Data

Stuart Brody

Category 2

(a) Drafting the Article

Stuart Brody

(b) Revising It for Intellectual Content

Stuart Brody

Category 3

(a) Final Approval of the Completed Article

Stuart Brody

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Sexuality, Love, and Sexual Well-Being in Old Age

Chapter

Apr 2025

Charting Salivary Oxytocin Across an Episode of Naturally Occurring Partnered Sex

Article

May 2025
ARCH SEX BEHAV

Oxytocin (OXT) has been linked to sexual behavior across several studies. However, scant work exists that investigates OXT concentrations across a sexual encounter and researchers have yet to examine OXT concentrations during partnered sexual activity in the home environment. In the present study, a non-clinical sample of 49 mixed-sex (i.e., 49 women, 49 men) young adult romantic partners were invited to engage in sexual activity within their home environments. Participants collected their own saliva samples before and after sex, which were then assayed for OXT. Dyadic analyses identified unique OXT trajectories for women and men and helped clarify mixed findings in prior work. Although time was not a significant predictor, the pattern of means indicated that women’s OXT concentrations were highest at the start and end of the sexual episode, whereas men’s OXT concentrations increased from the start to the end of the sexual episode. The findings also identified synchronous changes between women and men’s OXT, but only within the post-sex time interval (immediately post-sex, 20 min post-sex, and 40 min post-sex). Additionally, OXT concentrations pre- and post-sex were not associated with orgasm in ways that prior work would suggest. Implications for work on OXT, biological synchrony, and methodological comparison are discussed.

Sexuality and Social Perception: Between Freedom of Expression and Shame

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Apr 2025

Nataša Štern

Give Me More, and More Variety: Sexual Satisfaction Among BDSM and Kink Practitioners in Chile

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Apr 2025
J SEX RES

Sexual Health for Older Women : Implications for nurses and other healthcare providers

Article

Aug 2013

The Mate-Seeking, Acceptance & Rejection Scale for Singles (MARS)

Preprint

Full-text available

Mar 2025

Research on involuntary singlehood has increased dramatically, but is limited by there being no instrument that comprehensively measures individual differences in key variables reflective of difficulties in forming romantic relationships. Since involuntary singlehood is primarily attributed to failure in mate attraction, and potentially low effort at seeking mates, we developed the Mate-Seeking, Acceptance, and Rejection Scale for Singles (MARS). Singles report on the acceptance and rejection they received over the past 30 days, along with the effort they spent at seeking mates. Items were generated by act nomination (Study 1) which underwent statistical dimension reduction (Study 2a, N = 468). Mate-Seeking and Acceptance comprised factors Engagement, Emotional, and Physical, while Rejection factors were Non-Engagement, In-Person-Avoidance, Remote-Avoidance, and Tactical. For construct validity (Study 2b), MARS converged with Sociosexuality, Extraversion, Neuroticism and Romantic Loneliness. Factors were replicated by confirmatory factor analysis (Study 3, N = 333). Since singles report on the specific acceptance and rejection behaviors they receive, MARS may more precisely and objectively assess attraction difficulties than instruments probing self-judged attractiveness. Reports of attraction failure can also be examined against extent of mating effort. Sub-factors may diagnose common types of mating struggles, such as seeking long-term relationships while only acquiring sex.

The Mate-Seeking, Acceptance & Rejection Scale for Singles (MARS)

Presentation

Full-text available

Jun 2023

Cardiovascular disease and female sexual health across the life span: a bidirectional link

Article

Apr 2025
MATURITAS

The influence of computer-controlled MotorbunnyTM device use on sexual health and sleep behaviors

Preprint

Full-text available

Apr 2025

Sleep has gained much attention as a marker of cerebral health, and it is now well-established that sleep becomes disrupted in normal aging and in the setting of neurodegeneration. However, it remains less clear how sleep behaviors can be modified by lifestyle, and specifically, whether sexual behaviors may confer sleep benefits. Evaluating these possibilities requires pilot studies that can provide necessary prerequisite data to motivate or guide larger definitive trials. Here, we utilized established Patient-Reported Outcomes Measurement Information System (PROMIS) sleep disturbance, sleep relatedness, and sexual function and satisfaction scales questionnaires of sleep behaviors and sexual satisfaction in combination with wearable actigraphy devices and performed a pilot three-way, 18-day cross-over study in adult monogamous women. Three, four-day interventions including (i) intercourse with their partner, (ii) masturbation only with a computer-controlled female vibrational device, and (iii) combined use of both the partner and the device were assessed. We tested the hypothesis that sleep efficiency and rapid-eye-movement (REM) duration were similarly increased during all forms of sexual activity compared to three-day interval washout periods of sexual abstinence. Across all participants and measures (n=4; age=34.0±10.4 years), findings were consistent with improvements in sexual satisfaction and interest in sexual activity after the trial as assessed by the PROMIS sexual satisfaction survey (t-statistic) at intake (44.6±10.5) vs. closeout (55.2±6.5). There was no significant difference in established metrics of sleep behaviors for epochs when masturbation was used vs. a partner was used; however, 75% of women exhibited evidence of an increase in sleep efficiency and REM sleep duration during the masturbation epoch compared with washout epochs with sexual abstinence, with a large effect size of 0.799. Findings are intended to provide feasibility data on the relevance of computer-controlled masturbation devices and assessing these devices with wearable technologies, and corroborate anecdotal evidence of the impact of these devices on objective markers of women’s health. Key points In monogamous women with no history of major neurological or psychiatric disorder, we performed a pilot (n=4) three-way, 18-day cross-over study of how self-report and actigraphy-based wellness measures depended on (i) intercourse with their partner, (ii) masturbation only with a computer-controlled female vibrational masturbation device (Motorbunny™, New Mexico, NM, USA; motorbunny.com ), and (iii) combined use of both the partner and the device was applied. A clinical improvement, assessed by a 23.7% increase in the Patient-Reported Outcomes Measurement Information System (PROMIS) sexual function and satisfaction scales from intake to closeout was observed, consistent with improvements in self-report of sexual satisfaction over the focused sexual involvement trial. Sleep efficiency, defined as minutes asleep relative to minutes in bed, was most variable in washout periods of sexual abstinence, which partly stabilized for the exclusive masturbation device epoch and combined used of the masturbation device with a partner epoch. These findings are consistent with both the use of the masturbation device and combination masturbation device - partner reducing variation in sleep efficiency compared to sexual abstinence. The use of the masturbation device showed similar sleep efficiency and rapid eye movement (REM) sleep duration to a partner across all participants. However, in 75% of participants (i.e., 3 out of 4), REM sleep duration increased with the use of the masturbation device, with a large effect size of 0.799.

Prenatal androgen exposure predicts sexuality disorders: insights from anthropometric measurements and questionnaires

Article

Full-text available

Mar 2025

Background Sexual activity has been linked to various physical and psychological benefits, yet national surveys indicate a decrease in sexual engagement among American adults from the late 1990s to the early 2010s. The 2D:4D ratio, representing the relative lengths of the second and fourth digits, is commonly used as a biomarker for prenatal androgen exposure (PAE). This ratio may offer insights into the hormonal environment during fetal development, which could impact sexual attitudes and mental well-being. This study aimed to explore the associations between PAE, inferred via 2D:4D ratio, and various psychosocial factors, including sexual attitudes, mental health, and self-reported sexual satisfaction. Methods A cohort of male and female participants was assessed for 2D:4D ratios on both hands. Questionnaires captured a range of psychosocial and sexual measures, including the Arizona Sexual Experiences Scale (ASEX), the Sexual Satisfaction Questionnaire (SSI), the Sapiosexual Questionnaire (SapioQ), the Kinsey Scale for sexual orientation, and tools assessing mental health and quality of life (SF-12, PHQ-9, GAD-7, MDQ, PSQI). Statistical analyses were conducted to identify correlations between PAE, mental health, and sexuality, with gender differences considered. Results Women reported higher ASEX and SSI scores but lower SF-12 mental and physical health scores than men, consistent with smaller 2D:4D effect sizes reported in previous research. Overall, PAE did not correlate strongly with general mental health or sexual satisfaction. However, high PAE was associated with a greater openness to casual relationships, particularly among women, while low-PAE individuals prioritized intelligence over physical traits in partner preferences. Conclusions These findings suggest that PAE, as measured by the 2D:4D ratio, may be associated with certain adult psychosocial traits. Although correlations were weak, this study contributes to understanding the subtle role of PAE in shaping sexual attitudes and mental health, highlighting the need for further research in more diverse populations.

The psychobiology of human semen

Article

Full-text available

Aug 2006

Our interest in the psychological properties of semen arose as a byproduct of an initial interest in menstrual synchrony. In reviewing that literature we discovered several articles (Trevathan, Burleson, & Gregory, 1993; Weller & Weller, 1998) reporting that lesbians who live together fail to show menstrual synchrony. Since the evidence suggests that menstrual synchrony is mediated by the exchange of subtle olfactory cues among cohabitating women (Preti et al., 1986, Stern & McClintock, 1998) this struck us as peculiar, because lesbians would be expected to be in closer, more intimate contact with one another on a daily basis than other females who live together. What is it about heterosexual females that promotes menstrual synchrony, or conversely what is it about lesbians that prevents menstrual synchrony? It occurred to us that one feature that distinguishes heterosexual women from lesbians is the presence or absence of semen in the female reproductive tract. Lesbians have semen-free sex. Human semen is a very complicated mixture of many different ingredients. If you extract the sperm from semen, what is left is called seminal plasma. We speculated that there may be chemicals in seminal plasma that, through vaginal absorption, affect female biology and triggers the release of pheromones that function to entrain menstrual cycles among cohabitating women. Some of the components in semen pass through vaginal epithelial tissue, and within an hour or two after intercourse heightened levels of certain seminal chemicals can be detected in the female bloodstream (Benziger & Edelson, 1983).

Are Pleiotropic Mutations and Holocene Selective Sweeps the Only Evolutionary-genetic Processes Left for Explaining Heritable Variation in Human Psychological Traits?

Chapter

Full-text available

Nov 2010

Geoffrey Miller

This chapter proposes that the field of evolutionary psychology must take seriously the notion that evolution has accelerated during the Holocene. This rapid recent evolution might call into question three foundational assumptions of evolutionary psychology: that the most important environment of evolutionary adaptedness (EEA) for explaining individual differences resides in the Pleistocene; that evolutionary equilibrium models such as balancing selection are the most relevant theories for explaining heritable variation in personality, cognitive, and mental health traits; and the degree to which psychic unity or species-typicality characterizes human psychology.

The Suppression of Pain by Genital Stimulation in Females

Article

Nov 2012
Annu Rev Sex Res

Sex at Risk: Lifetime Number of Partners, Frequency of Intercourse and the Low AIDS Risk of Vaginal Intercourse

Book

Jun 1997

Stuart Brody

Prevalence of masturbation and associated factors in a British national probability survey

Article

Apr 2008

A stratified probability sample survey of the British general population, aged 16 to 44 years, was conducted from 1999 to 2001 (N = 11,161) using face-to-face interviewing and computer-assisted self-interviewing. We used these data to estimate the population prevalence of masturbation, and to identify sociodemographic, sexual behavioral, and attitudinal factors associated with reporting this behavior. Seventy-three percent of men and 36.8% of women reported masturbating in the 4 weeks prior to interview (95% confidence interval 71.5%-74.4% and 35.4%-38.2%, respectively). A number of sociodemographic and behavioral factors were associated with reporting masturbation. Among both men and women, reporting masturbation increased with higher levels of education and social class and was more common among those reporting sexual function problems. For women, masturbation was more likely among those who reported more frequent vaginal sex in the last four weeks, a greater repertoire of sexual activity (such as reporting oral and anal sex), and more sexual partners in the last year. In contrast, the prevalence of masturbation was lower among men reporting more frequent vaginal sex. Both men and women reporting same-sex partner(s) were significantly more likely to report masturbation. Masturbation is a common sexual practice with significant variations in reporting between men and women.

Factors in Marital Orgasm

Chapter

Jan 1978

Paul H. Gebhard

The search for successful strategies for the treatment of female orgasmic dysfunction has led to an investigation of the factors that correlate with orgasm in women. In this chapter Gehhard goes hack to some data collected by Kinsey and his co-workers on the frequency of marital orgasm. Gebhard focuses on three variables: the woman’s self-report of marital happiness, the duration of foreplay, and the duration of coitus. The findings show that women who are very unhappy in their marriages are unlikely to reach orgasm during coitus. It is doubtful that those briefer forms of sex therapy that largely focus on the sexual aspect of a couple’s relationship would affect the coital orgasm rate of such women. As was suggested by Lobitz in Part II, Chapter 5, assessment of such cases is extremely important and referral for marriage therapy might be suggested. Some cases will need marital therapy, while in those cases where the sexual problem is the major cause of marital unhappiness, sex therapy is indicated. The findings on duration of foreplay and coitus suggest that increasing the amount of time spent in these activities results in an increased probability that the woman will reach orgasm. However, there is a great deal of variability among women on these dimensions; some women are orgasmic with little or no foreplay and short coitus, while others are inorgasmic despite twenty or more minutes of foreplay and lengthy coitus. This seems to indicate that failure to reach orgasm is often a complex problem that is not likely to respond to simplistic “marriage manual” approaches of more foreplay prolonged coitus, and so on.

Are psychological characteristics related to risk of the metabolic syndrome? A review of the literature

Article

Jan 2007

Background: We evaluate the evidence that depression, anger, hostility, and anxiety are related to risk for the metabolic syndrome, focusing as well on its components of central adiposity and insulin resistance. In addition, we identify possible moderators of these associations and summarize plausible underlying biobehavioral pathways. Methods: Medline, PsycINFO, PubMed, and Web of Science searches were conducted using the keywords metabolic syndrome, syndrome x, central adiposity/obesity, visceral adiposity/obesity, body fat distribution, waist circumference, waist hip ratio, insulin resistance/sensitivity, glucose tolerance, psychological, depression, hostility, anger, cynicism, and anxiety. Results: The current literature provides cross-sectional evidence for an association between psychological characteristics and the metabolic syndrome. Prospective data, though limited, suggest that depression, hostility, and anger predict increased risk for the metabolic syndrome. Data on modifiers are too limited to permit definitive conclusions. Negative health behaviors and hypothalamic and sympathetic dysregulation are identified as plausible underlying pathways. Conclusions: More prospective studies, conducted with diverse samples, are needed to delineate the direction of this relationship and the proposed biobehavioral mechanisms; experimental investigations are needed to test for causality. Nevertheless, findings suggest that psychological characteristics, especially depression, hostility, and anger, may increase risk for the metabolic syndrome, providing a novel direction for prevention and treatment interventions.

Greater consumption of alcohol before sex is associated with lack of vaginal orgasm and greater frequency of other orgasm triggers

Article

Dec 2009

Sexual inactivity results in reversible reduction of LH bioavailability

Article

Apr 2002
INT J IMPOT RES

We have recently documented significantly reduced serum testosterone (T) levels in patients with erectile dysfunction (ED). To understand the mechanism of this hypotestosteronemia, which was independent of the etiology of ED, and its reversibility only in patients in whom a variety of nonhormonal therapies restored sexual activity, we measured serum luteinizing hormone [LH) in the same cohort of ED patients (n = 83; 70% organic, 30% nonorganic). Both immunoreactive LH (I-LH) and bioactive LH (B-LH) were measured at entry and 3 months after therapy. Based on outcome (ie number of successful attempts of intercourse per month), patients were categorized as full responders (namely, at least eight attempts; n = 51), partial responders (at least one attempt; n = 20) and non-responders (n = 16). Compared to 30 healthy men with no ED, baseline B-LH (mean +/- s.d.) in the 83 patients was decreased (13.6 +/- 5.5 vs 31.7 +/- 6.9 +/- IU/L, P < 0.001), in the face of a slightly increased, but in the normal range, I-LH (5.3 +/- 1.8 vs 3.4 +/- 0.9 IU/L, P < 0.001); consequently, the B/I LH ratio was decreased (3.6 +/- 3.9 vs 9.7 +/- 3.3, P < 0.001). Similar to our previous observation for serum T, the three outcome groups did not differ significantly for any of these three parameters at baseline. However, outcome groups differed after therapy. Bioactivity of LH increased markedly in full responders (pre-therapy = 13.7 +/- 5.3, post-therapy = 22.6 +/- 5.4, P < 0.001), modestly in partial responders (14.8 +/- 6.9 vs 17.2 +/- 7.0, P < 0.05) but remained unchanged in non-responders (11.2 +/- 2.2 vs 12.2 +/- 5.1). The corresponding changes went in the opposite direction for I-LH (5.2 +/- 1.7 vs 2.6 +/- 5.4, P < 0.001; 5.4 +/- 2.2 vs 4.0 +/- 1.7, P < 0.05; 5.6 +/- 1.2 vs 5.0 +/- 1.2, respectively), and in the same direction as B-LH for the B/1 ratio (3.7 +/- 4.1 vs 11.8 +/- 7.8, P < 0.001; 4.2 +/- 4.3 vs 5.8 +/- 4.2, P < 0.05; 2.1 +/- 0.7 vs 2.6 +/- 1.3, respectively). We hypothesize that the hypotestosteronemia of ED patients is due to impaired bioactivity of LH. This reduced bioactivity is reversible, provided that resumption of sexual activity is achieved regardless of the therapeutic modality. Because biopotency of pituitary hormones is controlled by the hypothalamus, LH hypoactivity should be due to the hypothalamic functional damage associated to the psychological disturbances which unavoidably follow sexual inactivity.

Body weight and obesity in adults and self-reported abuse in childhood

Article