The effect of brushing on hair loss in women

Abstract

Hair loss is a common, bothersome problem among women.
To evaluate the effect of different brushing frequencies on hair loss in women.
This was a non-randomized crossover study. During a 4-week period, 14 women were asked to brush their hair with different frequencies during each of the 4 weeks. The amount of hairs lost during each week was counted and the average hairs lost during each week was compared with that of a week with a different brushing frequency.
In all comparisons analyzed, hair loss was reduced by reducing brushing frequency. A subgroup analysis found strong association (p < 0.05) between brushing frequencies and the magnitude of hair loss. A limitation of the study was that the majority of the subgroup analyses did not find a statistically significant association between brushing frequency and amount of hair lost.
Brushing is associated with hair loss. Reducing the brushing frequencies may reduce the amount of hair shed.

Full text

PLEASE SCROLL DOWN FOR ARTICLE
This article was downloaded by:
[Gur, Itzhak]
On:
28 May 2009
Access details:
Access Details: [subscription number 911450525]
Publisher
Informa Healthcare
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
Journal of Dermatological Treatment
Publication details, including instructions for authors and subscription information:
http://www.informaworld.com/smpp/title~content=t713889756
The effect of brushing on hair loss in women
Alexander Kiderman ab; Itzhak Gur abc; Pnina Ever-Hadani d
a Clalit Medical Services, Jerusalem, Israel b Department of Family Medicine, Hebrew University, Jerusalem,
Israel c Department of Family Medicine, University of Washington, Seattle, Washington, USA d Braun School
of Public Health, Hebrew University, Jerusalem, Israel
First Published:June2009
To cite this Article Kiderman, Alexander, Gur, Itzhak and Ever-Hadani, Pnina(2009)'The effect of brushing on hair loss in
women',Journal of Dermatological Treatment,20:3,152 — 155
To link to this Article: DOI: 10.1080/09546630802512661
URL: http://dx.doi.org/10.1080/09546630802512661
Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf
This article may be used for research, teaching and private study purposes. Any substantial or
systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or
distribution in any form to anyone is expressly forbidden.
The publisher does not give any warranty express or implied or make any representation that the contents
will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses
should be independently verified with primary sources. The publisher shall not be liable for any loss,
actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly
or indirectly in connection with or arising out of the use of this material.

Journal of Dermatological Treatment. 2009; 20:3; 152–155
ISSN 0954-6634 print/ISSN 1471-1753 online © 2009 Informa UK Ltd.
DOI: 10.1080/09546630802512661
Journal of Dermatological Treatment. 2009; 20:3;
ORIGINAL ARTICLE
The effect of brushing on hair loss in women
ALEXANDER KIDERMAN1,2, ITZHAK GUR1,2,3 & PNINA EVER-HADANI4
1Clalit Medical Services, Jerusalem, Israel, 2Department of Family Medicine, Hebrew University, Jerusalem, Israel,
3Department of Family Medicine, University of Washington, Seattle, Washington, USA, and 4Braun School of Public
Health, Hebrew University, Jerusalem, Israel
Abstract
Background: Hair loss is a common, bothersome problem among women. Objective: To evaluate the effect of different brushing
frequencies on hair loss in women. Methods: This was a non-randomized crossover study. During a 4-week period, 14 women
were asked to brush their hair with different frequencies during each of the 4 weeks. The amount of hairs lost during each week
was counted and the average hairs lost during each week was compared with that of a week with a different brushing frequency.
Results: In all comparisons analyzed, hair loss was reduced by reducing brushing frequency. A subgroup analysis found strong
association (p < 0.05) between brushing frequencies and the magnitude of hair loss. A limitation of the study was that the majority
of the subgroup analyses did not nd a statistically signicant association between brushing frequency and amount of hair lost.
Conclusion: Brushing is associated with hair loss. Reducing the brushing frequencies may reduce the amount of hair shed.
Key words: Hair loss, wash test
Background
Under normal conditions, the scalp maintains a
homeostasis between hair growth and loss, resulting
in a normal hair appearance. Disruption of this
equilibrium results in hair loss (alopecia) or over-
growth (hypertrichosis). While hypertrichosis is
quite a rare symptom, hair loss is a common problem
in both sexes. As many as one-third of all women
over 40 years of age are affected by hair loss (1),
resulting in low self-esteem of the affected women
and deleterious psychological effects (2,3).
Many factors were shown to be associated with
hair loss in women, including: trauma (including
burning) to the scalp, medication usage, hair
chemicals and cosmetics usage, endocrine diseases,
hyperandrogenism, autoimmune diseases, nutri-
tional deciencies, and stressful events such as
illness or surgery (1,4). Nevertheless, the inuence
of brushing, a common behavioral manipulation of
the hair, on the process of hair loss is unknown. One
view is that brushing generates traction forces on the
hair shafts and follicles, promoting hair shedding
and alopecia, while another is that brushing may
promote hair growth. For example, brushing may
induce changes in some of the growth factors or
receptors of those factors found in the scalp and hair
follicles (5,6), inducing hair growth. Thus, the need
to evaluate the role of brushing in the process of hair
loss in women, in order to advise patients with a
proper recommendation, is indicated.
The aim of this study was to evaluate the
association between brushing frequency and hair
loss in women.
Methods
Women of Jewish origin were enrolled in a non-
randomized crossover study to evaluate the association
between brushing and hair loss in women. Non-
pregnant women aged 18–60 years old, who were
used to brushing their hair an even number of times
every day, were recruited from two family medicine
Correspondence: Itzhak Gur, Chemdat, 60695, Israel. Fax: 972 2 9944206. E-mail: gur008@gmail.com
Alexander Kiderman and Itzhak Gur contributed equally to this publication.
(Recevied 18 September 2008; accepted 25 September 2008)
Downloaded By: [Gur, Itzhak] At: 06:23 28 May 2009

Effect of brushing on hair loss in women 153
primary care clinics (A. K. and I. G.) in the
Jerusalem district, Israel. After providing written
informed consent, all volunteers were thoroughly
interviewed, had a complete physical examination by
one of the two principal investigators (A. K., I. G.),
and underwent blood testing. Individuals were
excluded if they gave birth during the 6 months
prior to enrollment, were pregnant during the study
period, declared using any medication or having any
illness known to be associated with hair loss,
changed medications or hair-related cosmetic prod-
ucts (shampoo, conditioner) during the 2-week
period prior to enrollment, were found (by interview
or physical examination) to have signs of a condition
known to be associated with hair loss, or found to
have any of the following in blood tests: the presence
of antinuclear antibody (ANA), low ferritin levels
(dened as < 20 ng/dl), evidence for thyroid hor-
mone disturbances (dened as thyroid stimulating
hormone (TSH) < 0.35 or > 5.5 mU/l) or low
hemoglobin (Hb) levels (Hb < 12.0 mg/dl).
Women enrolled in the study were asked not to
change their brush or comb, shampoo or conditioner
and not to curl or color their hair during the study
period. Enrollees were asked to brush their hair at
the same frequency (dened as: no. of brushings/day)
that they were used to prior to enrollment during
the second and fourth weeks of the study period,
and at half that frequency during the rst and
third weeks of the study period. Enrollees had to
count the number of hairs they found on their brush
or comb after each brushing (brush test). They were
also requested to take a shower with the draining
hole covered by a gauze, and then to count the
number of hairs trapped by the gauze (wash test).
Table I. Differences in mean hair loss (with 95% CI) and p-values of different measurement methods of compared weeks.
Brush test Wash test Total
week 1 vs week 2 –89.64286
(–179.909, 0.624130)
p < 0.0514
–4
(–28.21993, 20.21993)
p < 0.7231
–98.16667
(–224.2301, 27.89672)
p < 0.1145
week 1 vs week 4 84.14286
(–178.1312, 9.845487)
p < 0.0752
–4.666667
(–25.51069, 16.17736)
p < 0.6319
–96
(–220.8427, 28.84268)
p < 0.1187
week 3 vs week 2 –95.21429
(–171.5032, –18.92537)
p < 0.0183*
–4.5
(–21.37241, 12.37241)
p < 0.569
–94.33333
(–195.3578, 6.691113)
p < 0.0644
week 3 vs week 4 –89.71429
(–172.8224, –6.6061)
p < 0.0364*
–5.166667
(–19.5888, 9.255559)
p < 0.4471
–92.16667
(–196.6377, 12.30439)
p < 0.0782
weeks 1 + 3 vs weeks 2 + 4 –179.3571
(–346.8972, –11.81713)
p < 0.0378*
–9.166667
(–38.14377, 19.81044)
p < 0.5
–190.3333
(–413.808, 33.14137)
p < 0.0876
* = Statistically signicant difference
These methods have been found to be valid in
evaluating hair shedding in previous studies (7,8).
All the women received an information sheet and a
log book in which they had to write their counting
results. Results were collected at the end of the
4-week study period.
Statistical analysis
The number of hairs lost in each week, established
by the comb test, wash test or both were calculated
separately for each individual. Based on the assump-
tion that the within-individual standard deviation of
the weekly hair loss is 50 hairs, and for a probability
of 80% that the study will detect an intervention
difference of at least 60 hairs, at a two-sided 5%
signicance level, a total of 13 patients were needed
to be enrolled in this crossover study. For each
method (brush test, wash test or both), the means
and standard deviations of the number of hairs lost
during each week were calculated. Paired t-test
analysis was performed in order to evaluate the differ-
ence in the means by weeks differed by brushing
frequency. We analyzed the difference of the means of
the number of hairs found by the same counting
method during: 1st week versus 2nd week, 1st week
versus 4th week, 3rd week versus 2nd week and
3rd week versus 4th week. We also examined the dif-
ference of the means during weeks of half-frequency
brushing (1st and 3rd weeks) compared to weeks
with regular brushing frequency (2nd and 4th weeks).
Differences between 2 weeks of hair loss means were
considered signicant if the paired t-test reached a
p < 0.05. All analyses were made using Stata/IC 10.0
software (Statacorp LP, College Station, TX, USA).
Downloaded By: [Gur, Itzhak] At: 06:23 28 May 2009

154 A. Kiderman et al.
The study was approved by the Institutional Review
Board (IRB) of Hadassah Medical Organization,
Jerusalem, Israel.
Results
Twenty women volunteered to participate in the
study. Of those, one did not complete the study
period, and ve failed to comply with the protocol.
The mean age of the 14 women eligible for analysis
was 44 years (SD: 10.122); their mean TSH level
was 1.79 mg/dl (SD: 0.69), mean ferritin level was
57.14 ng/dl (SD: 52.26097, range: 20–223), and
mean Hb level was 14.12 (SD: 0.99). All the women
were ANA negative.
Table I shows the results of t-test analysis of the
mean number of hairs lost for the weeks that differed
by brushing frequency. The brush test achieved
signicant differences for the comparison of week 3
versus week 2, and week 3 versus week 4 and the
half-frequency weeks (weeks 1 and 3) versus the
normal brushing frequency weeks (weeks 2 and 4).
For the comparison of week 1 and the weeks with
normal frequencies (2 and 4), the brush test nearly
reached t-test signicance. Other measurements did
not reach a signicant level of difference by t-test
analysis. In all of the measurements, the mean
number of hairs lost during weeks with reduced
brushing frequencies was smaller than that of a week
with regular brushing frequency.
Discussion
Hair loss is a common complaint of women of all
ages. While several treatments for female hair loss
exist, the long-term efcacy, adverse effects, safety
and costs are unknown, making the utilization of
these treatment modalities unlikely by many women
(4,9). Our study showed that brushing increases the
shedding of hair, at least in the short term. With any
kind of measurement, daily hair loss was increased as
brushing frequency increased, and the brush test
found a strong association between frequency of
brushing and the amount of hair lost. Hair loss was
not found to be signicantly reduced during weeks
with reduced brushing frequency when evaluated by
the wash test alone or the total count of hairs
shed. This may be due to low overall measurements
made at the wash test, and the subjectivity by
which the counts were obtained by the enrollees.
Moreover, the exposure variability between the
two strategies (i.e. half-frequency brushing versus
normal-frequency brushing and the length of a week
for each exposure period) may have not been
sufcient to yield a signicant difference between
the two strategies. As this study was designed to
investigate the impact of brushing on hair shedding
in all women, most of the women in our study were
individuals who had not experienced hair loss or
alopecia and were young and healthy. We believe
that among older women and those who identify hair
loss as a problem, together with longer exposure
variability (i.e. a longer period for each strategy,
bigger differences in the frequency of brushing
between the two approaches), the mean number of
hairs lost will likely show a stronger association with
frequency of brushing by any means of diagnosis.
Thus, the results of this study may be underestimated.
The wash test showed low sensitivity, which may
explain why this method failed to show a signicant
association between combing and hair loss.
Although other sophisticated measures may have
produced better estimations, the methods used in
this study were implemented simply, were previously
validated (7,8), and enabled us to study this
phenomenon in the normal, healthy population.
The main strength of the current study is the use
of a crossover study design to answer the study
question. This approach eliminates most of the
potential confounders (and the need to adjust for
those), since each individual served as her own
control. Thus, the results of our study can be interpreted
with the assurance that potential confounders biased
the analysis to a minimum.
This study examines the inuence that brushing
frequency has on the amount of hairs shed in the
short term. Other studies will have to examine the
effect of reduced brushing frequency and its thera-
peutic efcacy in the long term among women who
do suffer from hair loss, and will have to evaluate the
benets and harms of the long-term pharmaceutical
and surgical treatments compared with the long-term
effect of reducing brushing frequency on overall hair
loss, hair appearance and patient satisfaction.
Acknowledgements
Source of funding
Dr Gur is a recipient of fellowship grants from the
Advancing Academic Family Medicine in Israel
(AAFMI) fellowship at the University of Washington,
Seattle, Washington, and The American Physicians
Fellowship for Medicine in Israel.
Conict of interests
The authors have no conict of interest to declare.
Prior presentations: none.
Downloaded By: [Gur, Itzhak] At: 06:23 28 May 2009

Effect of brushing on hair loss in women 155
References
Birch MP, Lalla SC, Messenger AG. Female pattern hair loss. 1.
Clin Exp Dermatol. 2002;27:383–8.
Williamson D, Gonzalez M, Finlay AY. The effect of hair loss 2.
on quality of life. J Eur Acad Dermatol Venereol.
2001;15:137–9.
De Koning EBG, Passchier J, Dekker FW. Psychological 3.
problems with hair loss in general practice and the treatment
policies of general practitioners. Psychol Rep. 1990;67:775–8.
Shapiro J. Hair loss in women. N Engl J Med. 2007;357: 4.
1620–30.
Paus R, Cotsarelis G. The biology of hair follicles. N Engl 5.
J Med. 1999;341:491–7.
Heymann WR. Epider mal growth factor receptor inhibitors 6.
and hair. J Am Acad Dermatol. 2008;58:642–3.
Rampini P, Guarrra M, Rampini E, Rebora A. Assessing hair 7.
shedding in children. Dermatology. 1999;199:256–7.
Guarrera M, Semino MT, Rebora A. Quantitating hair loss in 8.
women: A critical approach. Dermatology. 1997;194:12–6.
Price VH, Roberts JL, Hordinsky M, Olsen EA, Savin R, 9.
Bergfeld W, et al. Lack of efcacy of nasteride in
postmenopausal women with androgenetic alopecia. J Am
Acad Dermatol. 2000;43:(5 Pt 1)768–76.
Downloaded By: [Gur, Itzhak] At: 06:23 28 May 2009