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Capsaicin may have important potential
for promoting vascular and metabolic
health
Mark F McCarty,
1
James J DiNicolantonio,
2
James H O’Keefe
2
To cite: McCarty MF,
DiNicolantonio JJ,
O’Keefe JH. Capsaicin may
have important potential for
promoting vascular and
metabolic health. Open Heart
2015;2:e000262.
doi:10.1136/openhrt-2015-
000262
Received 6 March 2015
Revised 7 May 2015
Accepted 3 June 2015
1
Catalytic Longevity,
Encinitas, California, USA
2
Mid America Heart Institute,
St. Luke’s Hospital, Kansas
City, Missouri, USA
Correspondence to
Dr Mark F McCarty;
markfmccarty@gmail.com
ABSTRACT
Capsaicin, the phytochemical responsible for the
spiciness of peppers, has the potential to modulate
metabolism via activation of transient receptor potential
vanilloid 1 (TRPV1) receptors, which are found not only
on nociceptive sensory neurons, but also in a range of
other tissues. TRPV1 activation induces calcium influx,
and in certain tissues this is associated with increased
activation or expression of key proteins such as
endothelial nitric oxide synthase (eNOS), uncoupling
protein 2 (UCP2), KLF2, PPARdelta, PPARgamma, and
LXRα. The calcium influx triggered by TRPV1 activation
in endothelial cells mimics the impact of shear stress in
this regard, activating and increasing the expression of
eNOS—but also increasing expression of cox-2,
thrombomodulin, and nrf2-responsive antioxidant
enzymes, while decreasing expression of
proinflammatory proteins. Hence, dietary capsaicin has
favourably impacted endothelium-dependent vasodilation
in rodents. TRPV1-mediated induction of LXRαin foam
cells promotes cholesterol export, antagonising plaque
formation. Capsaicin-mediated activation of TRPV1-
expressing neurons in the gastrointestinal tract promotes
sympathetically mediated stimulation of brown fat, raising
metabolic rate. The increased expression of UCP2
induced by TRPV1 activation exerts a protective
antioxidant effect on the liver in non-alcoholic fatty liver
disease, and on vascular endothelium in the context of
hyperglycaemia. In rodent studies, capsaicin-rich diets
have shown favourable effects on atherosclerosis,
metabolic syndrome, diabetes, obesity, non-alcoholic
fatty liver, cardiac hypertrophy, hypertension and stroke
risk. Clinically, ingestion of capsaicin—or its less stable
non-pungent analogue capsiate—has been shown to
boost metabolic rate modestly. Topical application of
capsaicin via patch was found to increase exercise time
to ischaemic threshold in patients with angina. Further
clinical studies with capsaicin administered in food,
capsules, or via patch, are needed to establish protocols
that are tolerable for most patients, and to evaluate the
potential of capsaicin for promoting vascular and
metabolic health.
CAPSAICIN STIMULATES THE TRPV1 RECEPTOR
Transient receptor potential vanilloid 1
(TRPV1) is a membrane receptor that, when
activated, acts as a non-specific cation
channel, allowing influx of calcium.
Endogenous activators of TRPV1 include
heat, low pH, and certain lipid metabolites;
the best known exogenous activator is the
phytochemical capsaicin, responsible for the
spiciness in peppers.
1–3
Inasmuch as nano-
molar concentrations of capsaicin can acti-
vate this receptor (EC
50
=99 nM
4
), and
capsaicin is efficiently absorbed,
5
a suffi-
ciently high oral intake of capsaicin can
induce systemic activation of TRPV1.
Few studies have evaluated the clinical
pharmacokinetics of orally administered cap-
saicin.
6
After acute ingestion of 5 g of a
capsaicin-rich hot pepper extract, a peak
serum capsaicin level of 8.2 nM was observed
after 45 min; an hour later, capsaicin was no
longer detectible, presumably owing to rapid
hepatic metabolism.
7
In mice given a bolus
dose of 10 mg/kg capsaicin—far higher than
humans could be expected to use—the peak
serum concentration was about 3 µM; after
8 h, capsaicin was undetectable in serum. It
is therefore reasonable to expect that clinic-
ally tolerable intakes of capsaicin will achieve
serum concentrations in the nanomolar
range. Although capsaicin can inhibit certain
voltage-sensitive calcium channels with an
EC
50
of 5 µM or higher,
89
it does not appear
likely that this effect would be germane with
feasible oral intakes of capsaicin in humans.
TRPV1 is expressed by many nociceptive
sensory neurons, and its activation triggers
pain sensations. However, the massive neur-
onal calcium influx triggered by topical
exposure to sufficient concentrations of cap-
saicin is potentially cytotoxic, and triggers a
reflex down-regulation of TRPV1 activity.
10
Hence, these neurons become less respon-
sive to endogenous agonists for TRPV1,
resulting in analgesia.
11 12
Capsaicin skin
patches are currently employed clinically for
local pain control.
13
TRPV1 is also expressed by vascular endo-
thelial cells, hepatocytes, adipocytes, smooth
McCarty MF, DiNicolantonio JJ, O’Keefe JH. Open Heart 2015;2:e000262. doi:10.1136/openhrt-2015-000262 1
Cardiac risk factors and prevention
muscle cells, fibroblasts, various epithelia, T cells, mast
cells, and by neurons and astrocytes in the brain and
spinal column.
14
Hence, TRPV1 has the potential to
modulate the function of these cells by boosting their
intracellular-free calcium levels (Ca
i
). At present, there
does not appear to be any evidence that the desensitisa-
tion phenomenon evoked by capsaicin in sensory
neurons is pertinent to these other tissues; no down-
regulation of TRPV1 expression or function was noted
in the vasculature of newborn rats that had been
injected with potent doses of capsaicin for 5 days.
15
CAPSAICIN CAN INCREASE EXPRESSION AND ACTIVATION
OF ENOS
The impact of TRPV1 activation on vascular endothe-
lium is of particular interest, since an increase in Ca
i
is a
key mediator of the protective impact of pulsatile shear
stress—and of aerobic exercise—on endothelial func-
tion. This increase in Ca
i
acts rapidly to stimulate endo-
thelial nitric oxide synthase (eNOS) activity via binding
of the Ca
2+
/calmodulin complex; in addition,
Ca
i
-mediated activation of AMPK and Sirt1 stimulates
eNOS activity by modifying its phosphorylation and
acetylation status.
16 17
In the longer term, expression of
eNOS increases as well. Increased Ca
i
acts to boost the
expression and activity of the endothelium-specific tran-
scription factor KLF2 via a complex chain of events
involving activation of Ca2+/calmodulin-dependent
kinase kinase-βand downstream phosphorylations of
AMPK, ERK2, HDAC5, and the transcription factor
MEF2.
18 19
KLF2, in turn, promotes transcription of the
eNOS, thrombomodulin, and Nrf2-responsive antioxi-
dant enzymes, and works indirectly to suppress transcrip-
tion of various proinflammatory proteins.
20–24
As might be expected, treatment of endothelial cells
with capsaicin leads to increased expression and activa-
tion of eNOS.
25 26
Consistent with this, in wild-type, but
not TRPV1-knockout mice, dietary capsaicin enhances
endothelium-dependent vasodilation.
27
In spontaneously
hypertensive stroke-prone rats, dietary capsaicin
increases activation and expression of eNOS in the cere-
brovasculature, an effect associated with a reduction of
arteriolar hypertrophy, a delay in stroke occurrence, and
an increase in mean survival time.
28
In atherosclerosis-
prone ApoE knockout mice, dietary capsaicin slows
atherogenesis,
26 29
an effect which may reflect improved
endothelial function, but also a favourable impact of
TRPV1 activation on foam cells, increasing the expres-
sion of membrane transporters that mediate cholesterol
efflux; this latter effect is contingent on increased
expression of the transcription factor LXRα.
30
The
potential clinical relevance of these findings is demon-
strated by a controlled crossover study in which patients
with stable coronary disease and angina were treated
with capsaicin skin patches (typically employed for
control of lower back pain) or placebo patches. During
exercise testing, average time until ischaemic threshold
(1 mm ST segment depression) was significantly higher
during capsaicin administration (424 s vs 372 s,
p=0.027).
31
Notably, serum NO levels (assessed by meas-
uring its stable metabolites nitrate and nitrite) were
found to be significantly higher when the patients were
using the capsaicin patches, suggesting that increased
NO production within the coronary tree may have been
responsible for the improved exercise tolerance asso-
ciated with capsaicin.
Capsaicin feeding has shown an antihypertensive
effect in rats genetically prone to this disorder, and this
compound also blunts the nocturnal rise in blood pres-
sure or development of hypertension in mice fed a high
salt diet.
27 32 33
Conceivably, improved NO function may
underlie these effects. Capsaicin dilates the coronary
arteries of pigs ex vivo, an effect that is half-maximal at
116 nM; this effect is blocked by endothelial denudation
and inhibitors of eNOS, and is less notable with coronar-
ies from pigs experiencing metabolic syndrome, which
disrupts eNOS function via oxidative stress.
34
Release of
CGRP from perivascular sensory neurons may also con-
tribute to the vasodilatory impact of capsaicin.
35
Paradoxically, the direct impact of capsaicin on vascular
smooth muscle is to provoke constriction, owing to
increased calcium influx.
36
Hence, the net impact of
capsaicin on vascular tone and blood pressure may
reflect complex interactions and countervailing effects.
Several case histories of acute hypertensive crisis pro-
voked by very high intakes of chilli peppers have
appeared; down-regulated function of CGRP-producing
neurons owing to acute high capsaicin exposure has
been suggested as an explanation for this effect.
37 38
On
the other hand, a more moderate capsaicin exposure
associated with the use of capsaicin patches—sufficient
to alleviate angina pain—did not alter plasma levels of
CGRP, but plasma levels of NO metabolites increased.
31
Whether and how moderate, clinically tolerable dosing
with capsaicin would influence human hypertension has
not yet been assessed.
The antihypertensive effect of dietary capsaicin in
salt-fed rats may reflect, in part, an inhibitory effect on
renal sodium retention. In the kidney, cortical collecting
duct epithelium expresses TPRV1, and its activation
decreases the function and expression of epithelial
sodium channels in these cells, resulting in increased
urinary sodium loss.
33
CAPSAICIN BOOSTS UCP2 EXPRESSION IN CERTAIN
TISSUES
TRPV1 activation has also been shown to increase
expression of uncoupling protein 2 (UCP2) in endothe-
lial cells, hepatocytes and cardiac tissue.
39–41
In the
heart, this effect may be downstream from increased
expression of PPARdelta, a factor which opposes cardiac
hypertrophy and fibrosis.
41 42
Hence, dietary capsaicin
was found to oppose the cardiac hypertrophy induced
by a high salt diet in mice—an effect not seen in TRPV1
2McCarty MF, DiNicolantonio JJ, O’Keefe JH. Open Heart 2015;2:e000262. doi:10.1136/openhrt-2015-000262
Open Heart
knockout mice.
41
With respect to UCP2, this functions
as a mitochondrial uncoupling protein when mitochon-
drial substrate oxidation is high and superoxide gener-
ation is elevated; by diminishing the proton gradient
across the mitochondrial inner membrane, UCP2
relieves the resistance to electron flow down the respira-
tory chain and hence decreases the rate at which elec-
trons are shunted to superoxide generation at
complexes I and III.
43–45
UCP2 can be of particular value when cells that are
constitutively permeable to glucose—such as vascular
endothelium—are subjected to hyperglycaemia. Under
these circumstances, elevated glucose oxidation in the
Krebs cycle tends to boost mitochondrial superoxide
generation, an effect opposed by UCP2.
46–48
In diabetic
mice, capsaicin administration was shown to alleviate vas-
cular oxidative stress and improve endothelium-
dependent vasodilation—a phenomenon not seen in
UCP2 knockout mice rendered diabetic.
39
In men with
diabetes, a polymorphism in the UCP2 promoter
(-866G>A), linked to increased expression of UCP2 in
some studies, was found to be associated with signifi-
cantly lower risk for developing coronary disease
49
—
consistent with a protective impact of UCP2 expression
on cardiovascular risk in diabetics.
Hepatocyte expression of UCP2 can be protective in
the context of non-alcoholic fatty liver disease. Under
these circumstances, increased mitochondrial oxidation
of fatty acids contributes to the oxidative stress that plays
a mediating role in this syndrome. The uncoupling activ-
ity of UCP2 decreases this generation of superoxide, and
by boosting the rate at which mitochondria can metabol-
ise fatty acids, helps to mitigate the surplus of fatty acids
within hepatocytes.
50 51
Indeed, capsaicin-rich diets have
been found to alleviate non-alcoholic fatty liver disease
in mouse models of this disorder.
39 52
TRPV1-mediated
induction of PPARdelta likely plays a role in this effect,
and may be upstream from UCP2 induction.
52
Capsaicin-mediated induction of UCP2 in hepatocytes
may have potential as an adjuvant to weight control strat-
egies which attempt to optimise hunger control, select-
ive fat oxidation, and thermogenesis by improving the
efficiency of hepatic fatty acid oxidation.
53
CAPSAICIN EFFICACY IN METABOLIC SYNDROME
In obese mice, capsaicin injections exert an anti-
inflammatory effect on adipose tissue, suppressing
production of IL-6, TNF-α, MCP-1, and cox-2, while
boosting that of adiponectin, and decreasing macro-
phage infiltration.
54
The authors of this study speculate
that enhanced activity of PPARgamma might account for
these effects, although they do not present evidence to
support this contention. A subsequent study showed that
dietary capsaicin had a beneficial metabolic impact on
genetically diabetic KKAy mice—reducing plasma levels
of glucose, insulin and triglycerides, boosting those of
adiponectin, and exerting the same anti-inflammatory
effects on adipose tissue as reported in the previous
study.
55
And more recent studies with topically applied
or dietary capsaicin in fat-fed mice did indeed confirm
that adipose expression of PPARgamma was increased in
the treated mice, whereas gain in weight and visceral fat
mass were blunted.
56 57
One of these studies reported
that capsaicin treatment also boosted visceral adipose
expression of hormone-sensitive lipase and of
connexin-43; the latter is required for gap junctional
communications between adipocytes that are required
for efficient lipolysis.
57
This study also demonstrated that
exposure of mesenteric adipose tissue from obese
humans to capsaicin, likewise increased expression of
these proteins.
57
The beneficial effects of capsaicin on metabolic syn-
drome in mice may be mediated in part by increased
secretion of glucagon-like peptide-1 (GLP-1). Indeed,
gastric administration of capsaicin has been shown to
evoke increased secretion of GLP-1 by the gastrointes-
tinal (GI) tract, and to raise plasma levels of this
factor.
58
This effect is absent in TRPV1 knockout mice.
Increased calcium influx into intestinal L cells may
mediate this impact on GLP-1 secretion.
How activation of the TRPV1 receptor manages to
increase the expression of various regulatory factors—
UCP2, PPARalpha and PPARdelta, LXRα—remains
obscure; calcium influx per se seems unlikely to mediate
all these effects. Perhaps TRPV1 has a distinctive micro-
environment reflecting binding affinities to other pro-
teins, such that influxing calcium tends to preferentially
activate certain calcium-binding proteins in this micro-
environment. It is also conceivable that some of
TRPV1’s signalling effects are independent of calcium
influx.
THERMOGENIC AND APPETITE CONTROL EFFECTS OF
CAPSAICIN AND CAPSIATE
Another intriguing TRPV1-dependent effect of capsaicin
ingestion is activation of brown adipose tissue. Activation
of TRPV1-expressing neurons in the digestive tract sends
a signal to the brain via the vagal nerve; this in turn
evokes an activation of sympathetic neurons that is
selective for brown fat—that is, the heart rate is not
impacted.
59 60
Many clinical trials have evaluated the
impact of capsaicin ingestion on metabolic rate, respira-
tory quotient and appetite; these conclude that capsa-
icin can modestly enhance energy expenditure, while
boosting fat oxidation (lower RQ) and diminishing
appetite—effects conducive to weight control.
61 62
Similar effects are seen with a non-spicy analogue of
capsaicin, capsiate, which owing to lower stability does
not induce pain in the oral cavity and appears to have
limited systemic availability.
59 60 63–65
Capsiate is found
in certain sweet peppers; it is very similar in structure to
capsaicin, and can activate TRPV1, with an affinity about
one-third that of capsaicin (EC50=290 nM).
4
Whereas
capsaicin contains an amide linkage that is relatively
McCarty MF, DiNicolantonio JJ, O’Keefe JH. Open Heart 2015;2:e000262. doi:10.1136/openhrt-2015-000262 3
Cardiac risk factors and prevention
stable, capsiate contains an ester that is readily cleaved;
when administered orally, intact capsiate fails to reach
oral TPRV1-expressing neurons, but does manage to
stimulate such neurons lower in the GI tract. No intact
capsiate appears in the portal blood after oral adminis-
tration, but its hydrolysis products are detectible, imply-
ing that capsiate is hydrolysed during the process of
absorption.
65
Hence, the effects of capsiate attributable
to TPRV1 agonism appear to be mediated by stimulation
of GI sensory neurons.
Both capsaicin and capsiate may have modest utility as
adjuvants to weight control programmes.
Supplementation with capsiate (9 mg daily) for 12 weeks
in a double-blind study was shown to decrease abdom-
inal fat mass relative to placebo, albeit to a modest
extent.
66
(Over the 12 weeks, the capsiate group, on
average, lost 0.4 kg of weight and 1 cm of waist girth
beyond that achieved with placebo—not an effect of
much practical importance unless it persists and
increases over time.) Not surprisingly, the effects of cap-
saicin or capsiate on thermogenesis are most notable in
humans bearing detectible amounts of brown fat;
63
however, there is some evidence that prolonged inges-
tion of these agents may lead to recruitment of brown
fat in humans.
67
These effects on thermogenesis are
modest in magnitude; there do not appear to be any
reports of clinically significant hyperthermia with inges-
tion of capsaicin or capsiate.
Some studies have also evaluated the impact of oral
capsaicin or capsiate on appetite and subsequent food
consumption in various contexts. The findings of these
studies have been inconsistent, though an overview of
these studies by Ludy et al
61
concludes that, on balance,
consumption of these agents tends to decrease orexi-
genic sensations. In positive studies, capsaicin-treated
subjects reported less desire to consume fatty foods,
sweet foods, salty foods and food overall, and achieved
greater satiety after meals. Also, calorie consumption
during subsequent meals was sometimes reported to
drop after capsaicin consumption. The fact that capsiate
blunted appetite in some studies suggests that these
effects are mediated by TRPV1-expressing GI neurons.
Arguably, capsaicin in the GI tract triggers a vagal signal
to appetite-regulatory centres in the brain; however,
increased secretion of GLP-1 may also play a role in cap-
saicin’s impact on appetite.
IMPACT ON GASTRIC PATHOLOGY
Ironically, many laypeople are under the impression that
spicy foods can cause ulcers; to the contrary, there is evi-
dence that capsaicin tends to prevent and accelerate
healing of gastric ulcers.
68–70
This phenomenon reflects
capsaicin’s ability to inhibit gastric acid secretion, boost
secretion of alkali and mucous, and stimulate gastric
blood flow. A clinical study found that the gastric tissue
damage and microbleeding induced acutely by indo-
methacin or ethanol ingestion was blunted if capsaicin
was administered concurrently.
69
These findings have
prompted the suggestion that capsaicin could be used as
a protective adjuvant to non-steroidal anti-inflammatory
drug therapy.
69 70
Limited epidemiology suggests that
gastric ulcers may be less common in ethnic groups that
prefer spicy foods.
68
With respect to risk of gastric cancer, the epidemi-
ology on spicy foods is rather perplexing. A recent
meta-analysis of pertinent studies in Korea and Mexico,
where heavy consumption of spicy foods is common,
concludes that moderate daily intakes of capsaicin (less
than 30 mg daily) are associated with a significant
decrease in gastric cancer risk (OR=0.55, p=0.003) rela-
tive to non-consumption—perhaps reflecting the gastro-
protective effects of capsaicin—whereas, heavy daily
consumption is associated with a notable increase in risk
(OR=1.94, p=0.0004).
71
Bley et al
72
suggest that the
increase in risk associated with heavy consumption of
spicy traditional foods might reflect mutagens present in
these foods, rather than an effect of capsaicin per se.
Aflatoxins, pesticides and nitrosamines or their precur-
sors have been detected in chillies sold for human con-
sumption.
72
The traditional Korean dish kimchi, a salty
pickled cabbage usually fermented with red pepper and
linked to increased risk of gastric cancer, is typically high
in nitrate and contains N-nitroso compounds with muta-
genic potential; the high salt content of this food may
act as gastric co-carcinogen.
73–76
Studies with high-purity
capsaicin indicate that it is not genotoxic; in animal
studies, capsaicin lacks carcinogenicity, and opposes the
carcinogenicity of certain mutagens.
72
Further clarifica-
tion of this situation will be desirable if in the future
people are encouraged to consume more capsaicin for
potential health benefits.
DOSAGE CONSIDERATIONS
In rodents, large metabolic effects have been reported
with dietary capsaicin intakes in the range of 0.01–
0.02% of diet. If a human were to eat (say) 400 g dry
weight of food daily, 0.01% of diet would correspond to
40 mg capsaicin. Oral administration of capsaicin repre-
sents a clinical challenge—many people, especially those
not acclimated to a spicy diet, do not enjoy the oral pain
associated with capsaicin-laced foods, and capsaicin cap-
sules may cause GI distress in some persons; this latter
effect is mitigated somewhat by ingesting capsaicin cap-
sules with meals. When Lejeune et al
77
had study volun-
teers take 45 mg capsaicin three times daily with meals,
24% of them experienced significant stomach discom-
fort and were allowed to cut this dose in half; however,
this dose regimen seems likely to be a higher dose than
would be required for metabolic benefits.
Hot peppers typically contain capsaicin in conjunction
with lesser amounts of its analogues, dihydrocapsaicin
and nordihydrocapsaicin; the latter is a very minor com-
ponent, but dihyrocapsaicin may constitute as much as
40% of total capsaicinoids. The relative proportion of
4McCarty MF, DiNicolantonio JJ, O’Keefe JH. Open Heart 2015;2:e000262. doi:10.1136/openhrt-2015-000262
Open Heart
capsaicin and dihydrocapsaicin in a food is of little prac-
tical import, as the abilities of these compounds to
activate TRPV1 are roughly equivalent. Commercial cap-
sules of cayenne pepper are available that provide
40 000–100 000 Scoville heat units per capsule. The
Scoville scale quantifies the spicy heat (or pungency) of
foods which contain capsaicinoids; a gram of capsaicin
corresponds to 16 million Scoville heat units; a gram of
dihydrocapsaicin to 15 million units; and a gram of nor-
dihydrocapsaicin to 9.1 million units. Therefore, a
capsule claiming 100 000 Scoville heat units can be
expected to contain about 6.6 mg of capsaicinoids.
Consuming three of these daily with meals will provide
about 20 mg, and those who enjoy spicy foods could sup-
plement this with peppers, pepper sauces, or cayenne
powder added to foods. Perhaps this would be an appro-
priate ‘baseline’regimen to study clinically. Topical
administration of capsaicin in patches may represent a
reasonable alternative in people unable to tolerate it
orally—albeit this will be a more expensive option, and
local pain is commonly experienced for an hour or
more after patch application.
78
EXPLORING THE HEALTH POTENTIAL OF CAPSAICIN
This brief overview should make it clear that dietary cap-
saicin—and, likely to a more limited degree, non-
pungent capsiate—has intriguing potential for health
promotion. Rodent studies suggest that capsaicin may
merit clinical evaluation with respect to endothelial
function, progression of atherosclerosis (most notably in
diabetics), angina, non-alcoholic fatty liver disease,
cardiac hypertrophy, metabolic syndrome, hypertension,
obesity and gastric ulceration. (See table 1 for a
summary of these potential benefits and the mechan-
isms that may underlie them.) In addition to the many
studies assessing capsaicin’s impact on metabolic rate
and adiposity, the trial of topical capsaicin in patients
with angina, and the studies documenting capsaicin’s
gastroprotective effects, represent initial efforts in this
regard. A study examining endothelium-dependent vaso-
dilation in diabetics might be particularly useful, as a sys-
temically adequate dose of capsaicin could be expected
to have a notably favourable impact on this parameter.
Assessment of the dose-dependency of this effect could
provide useful insight into capsaicin clinical dosage sche-
dules which could provide systemic metabolic benefits.
Both oral and topical application of capsaicin could be
tested in this regard. The rodent literature is sufficiently
intriguing that serious efforts to evaluate the feasibility
of capsaicin administration as a clinical or lifestyle strat-
egy appear to be warranted. However, owing to the fact
that TRPV1 receptors are expressed on a wide range of
tissues, the possibility that high-dose capsaicin might
exert unanticipated or unwanted physiological effects
should be borne in mind.
Contributors MFM conceived of this essay, and wrote the initial draft. JJD
and JHO’K suggested revisions and wrote portions of the revised draft.
Competing interests JJD works for a company that sells capsaicin products,
but he has no direct role in marketing or selling them. JHO’K and MFMC have
ownership interests in companies that make nutritional supplements, but
these companies do not sell capsaicin products.
Provenance and peer review Not commissioned; externally peer reviewed.
Open Access This is an Open Access article distributed in accordance with
the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license,
which permits others to distribute, remix, adapt, build upon this work non-
commercially, and license their derivative works on different terms, provided
the original work is properly cited and the use is non-commercial. See: http://
creativecommons.org/licenses/by-nc/4.0/
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Table 1 Health benefits of capsaicin administration suggested by preclinical and clinical research
Condition benefited Likely mechanisms of action
Atherosclerosis
26 29 30
Improved endothelial function, including eNOS activation/induction; induction of LXRalpha in
foam cells, promoting cholesterol export
Diabetic vasculopathy
39
Induction of UCP2 and eNOS in endothelium
Stroke
28
Improved endothelial function, including eNOS activation/induction
Angina
31
Improved endothelium-dependent vasodilation of coronary arteries
Hypertension
27 32 33
Activation/induction of eNOS; decreased renal sodium retention
Metabolic syndrome
54–58
Decreased adipose inflammation—reflecting PPARgamma induction
Cardiac hypertrophy
41
Induction of PPARdelta
Fatty liver
39 52
Induction of UCP2 in hepatocytes; decreased adipose inflammation Increased GLP-1 secretion
Obesity
56 57 61 62 66
Sympathetic activation of brown fat thermogenesis Improved appetite control—vagal signal to
appetite centers, ↑GLP-1; increased adipocyte capacity for lipolysis
Gastric ulceration
68–70
Decreased acid secretion; increased alkali; increased gastric blood flow
eNOS, endothelial nitric oxide synthase; GLP-1, glucagon-like peptide-1; UCP2, uncoupling protein 2
McCarty MF, DiNicolantonio JJ, O’Keefe JH. Open Heart 2015;2:e000262. doi:10.1136/openhrt-2015-000262 5
Cardiac risk factors and prevention
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Cardiac risk factors and prevention
