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Influence of season on some skin properties: winter vs. summer, as
experienced by 354 Shanghaiese women of various ages
H. Qiu*, X. Long*, J. C. Ye*, J. Hou*, J. Senee*, A. Laurent
, R. Bazin
, F. Flament
, A. Adam
, J. Coutet
and B. Piot
*L’Ore
´al Research and Innovation Shanghai, China and
L’Ore
´al Research and Innovation, Chevilly-Larue, France
Received 27 July 2010, Accepted 19 December 2010
Keywords: clinical evaluation, instrumental evaluation/physical measurements, season influence, skin functional property, skin aging signs
Synopsis
The facial skin of 354 women, aged 18–80, living in Shanghai,
was investigated over two successive 6 month periods, summer
and winter. Results from clinical assessments indicate that aging
signs, such as wrinkling and sagging, are unaffected over such
period.
However, physical measurements revealed alterations in some
functional criteria of the skin, such as sebum output, skin colour,
melanin content of pigmented spots, skin hydration, all being
increased during summer. The relationships between all criteria, as
well as technical or applied inferences/consequences from this
study, are discussed.
Re
´sume
´
La peau du visage de 354 femmes re
´sidant a
`Shanghai, a
ˆge
´es de
18 a
`80 ans a e
´te
´observe
´ea
`deux pe
´riodes successives, e
´te
´et
hiver. Les re
´sultats des e
´valuations cliniques montrent que
Les signes lie
´s au vieillissement, tels que rides et affaissement des
traits, ne sont pas modifie
´s durant ces pe
´riodes.
En revanche, des modifications de certains crite
`res fonctionnels
cutane
´s ont e
´te
´observe
´es par les mesures physiques, telle la
production se
´bace
´e, la couleur de la peau, le contenu me
´lanique
des taches pigmentaires, l’hydratation, tous e
´tant augmente
´sau
cours de l’e
´te
´.
Les relations entre ces crite
`res, ainsi que les conse
´quences tech-
niques ou applique
´es re
´sultant de cette e
´tude, sont discute
´es.
Introduction
Skin, like the Latin God Janus, offers two faces. As a first protective
envelope towards the external world, it daily faces various facets:
micro-organisms, air pollutants, cold, heat, dryness, humidity, sun,
wind, snow, etc. all factors possibly combined that skin is exposed
to lifelong at various extents. Internally, it undergoes progressive
alterations, over decades, resulting from a regular decline in many
biological functions, globally defined as the aging process, including
intrinsic (chronological) and sun-induced [1, 2], otherwise known
as photo-ageing. These, combined, lead to slow and progressive
changes in both skin functions and structures, ultimately altering
physical appearance, most of the time assessed on the face by one-
self and others. Facial skin is both continuously exposed to external
stresses and reflects internal changes. As compared to protected
skin sites, facial skin is logically more affected by external factors
[3, 4] These changes encompass many different signs such as
pigmentary disorders, loss of elasticity and skin dryness [5]. In
women, most of them appear more marked from the menopausal
period [6, 7]. All these events have been the subject of a number of
papers, as recently reviewed [8–10].
Amongst human ethnical groups, skin show different changes or
specific signs, according to geographical conditions and phenotypic
expressions, reflecting different skin responses to same stress or age-
ing factor. Distinct skin features can be observed by comparing
American-Caucasian with Japanese females [11] and French-
Caucasian with Chinese [12]. Even within a same ethnic group, as
shown by Tsukahara et al. [13], the facial signs of aging show
affected by geographic and climatic factors such as latitude, tem-
perature and humidity.
This particular point led us to focus on seasonal changes induced
in skin within a same city (Shanghai, China) and their possible influ-
ence on some skin features, using both clinical assessments and
objective measurements. Shanghai climate usually shows rather
short spring and autumn periods: summer rapidly comes after winter
and vice versa. Accordingly, we organized the present study in Shang-
hai twice on the same human cohort, on these two peak periods of
the year, with the aim to address two questions:
1. To which extent some clinical signs and skin functions possibly
vary within a 6 month period, through climatic changes, a
rather short period where aging process should have likely a
little impact?
2. If any, are some of these changes in skin clinical or functional
criteria influenced by subject age? In short, how does older skin
react to climatic changes, as compared to younger skin?
Materials and methods
Climatic data, people habits
Shanghai is situated at latitude 31north, similar to that of Marrak-
ech (Marocco) or the state of Louisiana (U.S). Despite vicinity to sea
(from the Chinese Shang, above, Hai, sea), Shanghai climate is of a
continental type, with high temperature (T= 35–40C) and relative
humidity (RH equal or above 70%) in summer. Winter temperature
is usually around 0–5C with comparable RH%.
Shanghai shows a temperate climate from April to October when
most people wear short sleeves clothes. Sun exposure is generally
Correspondence: Huixia Qiu, L’Ore
´al Research and Innovation Shan-
ghai, 550 Jin Yu Road, Jinqiao, Pudong Area, 201206 Shanghai,
China. Tel.: +86 21 38723785; fax: +86 21 3872372; e-mail:
cqiu@rd.loreal.com
International Journal of Cosmetic Science, 2011, 1–7 doi: 10.1111/j.1468-2494.2011.00639.x
ª2011 The Authors
ICS ª2011 Society of Cosmetic Scientists and the Socie
´te
´Franc¸aise de Cosme
´tologie 1
avoided (for cultural reasons) and many Shanghaiese women daily
use sun protective elements (umbrella, masks, UV plastic shields,
etc.) on sunny days.
The present study was performed throughout August 2007
(average T= 29.5C and RH = 70.2%) and January 2008 (average
T= 9.1C and RH = 70.3%) at the L’Ore
´al R&D facilities, Pudong-
Shanghai.
Subject cohort
400 healthy Shanghaiese women (having lived in Shanghai for
at least 10 years), aged 18–80, were recruited by agencies in
summer. Unfortunately, only 354 were able to visit us in winter,
for personal reasons, and current paper is therefore based on the
matched volunteer coming both in summer and winter, i.e. a
total number of 354. They were informed about study proto-
col and signed an informed consent. No particular exclusion
criteria were used except skin disease. In the end, the recruit-
ment phase allowed us to get eight groups of subjects see
Table I.
All clinical and physical assessments during both summer and
winter were performed on bare skin (no cosmetics applied for
3 days prior to the study apart soap or cleanser), after 30 min
acclimation delay in our facility under a stable and resting environ-
ment (T=21±1C, RH = 45 ± 5%).
Clinical assessment
Clinical grading of the various facial signs was performed by
trained technicians, using our recently published ‘Skin Aging
Atlas, Asian Type’ [14]. This atlas affords standardized pictures
of eight facial signs and their respective degree of severity scale.
Figure 1 illustrates one example of these standardized pictures. It
represents a precious abacus for attributing a given score of
severity to a given sign with lowest uncertainty. In the present
study, we only focused on two types of pattern at different
locations: (i) skin wrinkling (forehead, inter-ocular crow’s feet
and underneath eye wrinkles) and (ii) skin sagging (dropping
upper eyelid, eye bags, neck sagging, and lower face ptosis)
(Table II).
Table I Demographics of the study population, e.g., number of
subjects in each age group
Age group Number
18–27 44
28–35 40
36–42 46
43–50 48
51–57 47
58–65 48
66–72 43
73–80 38
Figure 1 Example of Asian clinical skin atlas standard picture: crow’s feet wrinkles.
ª2011 The Authors
ICS ª2011 Society of Cosmetic Scientists and the Socie
´te
´Franc¸aisedeCosme
´tologie
International Journal of Cosmetic Science,1–72
Influence of season on some skin properties H. Qiu et al.
Physical evaluations
The following instruments were used:
1. Chromasphere
[15] is a diffuse daylight lightening device
coupled to a spectro radiometer and/or calibrated 3CCD digital
cameras. It allows multi scale colour measurements on the face.
Chromasphere
together with a Skin Color Chart
[16] was
used to measure the facial skin tone by L
*
a
*
b
*
Ch parameters.
The number of hyper-pigmented spots was calculated using a
proprietary software on defined area on cheek. Chromaticity
was calculated according to the following formula.
Chromaticity ¼ða2þb2Þ1=2
2. The melanin content of hyper-pigmented lesions, when pres-
ent, was measured using Mexameter
(Courage & Khazaka,
Ko¨ln, Germany).
3. Sebutape
(CuDerm Corporation, TX, U.S.A.) and Sebumeter
(Courage & Khazaka, Ko¨ln, Germany) were used to quantify the
density of active follicles and the amount (lgcm
)2
) of sebum
(assessed from the value of first sampling as index) on the fore-
head, respectively, half an hour post-degreasing, using a 70%
ethanol/water solution.
4. Both Corneometer
(Courage &Khazaka, Koln, Germany) and
Skin chip
[17] were used for measuring skin hydration on cheek.
In our study, the grey levels of Skin chip
were set up for record-
ing the state of dryness of the skin surface. This electronic device
allows an indirect measurement of the water presence (black
values) or absence (white values). Measuring the grey levels
between these limits provides an index of the dryness of the skin
surface.
Results
Clinical signs of wrinkles and firmness: As initially suspected, none of
the recorded signs showed particular change over the 6 months
period (Figs 2 and 3). In brief, facial wrinkle formation and sagging
are not particularly affected by such 6-month seasonal period.
Skin colour and pigmentation spot: In agreement with previous
studies [12], aging lead to progressively darker skin tones (Figs 4
and 5) as reflected by Lightness and Chromaticity values with sta-
tistically significant age effect in all groups. The density of hyper
pigmented spots, highly linked to age, tends to increase in summer
(Fig. 6) as compared to winter. Nevertheless, these hyper pig-
mented spots show significant and almost identical (absolute values
of Mexameter
) increase in melanin content index (Fig. 7) in all
age groups during summer.
Sebum production
Basically, the density of active follicles, i.e. the number of follicles/cm
2
excreting sebum is clearly not affected by season (Fig. 8). However, as
shown by Sebumeter
values, although not statistically significant,
active follicles seem to excrete more sebum during summer than win-
ter, almost irrespective of age (Fig. 9). As regards relationship with
aging, we confirm here many previous studies [18–20], showing a
rather constant decline in sebum production from the 40s.
Skin hydration
Both techniques used show comparable effect of season. Summer
clearly and statistically increases skin hydration (Figs 10 and 11).
Figure 12 shows that the techniques appear statistically inversely
correlated. As regards aging, the study shows a trend towards a
drier skin (less hydrated) with age, although such effect seems to
plateau from the 58 to 65 years class. Such finding slightly differs
from that of a previous work [21] where dry skin, on the forehead
of a Chinese population, was found increased only from the 70s.
Discussion
The study reported here indicates that the most marked seasons in
Shanghai, i.e. summer and winter, do induce slight changes in
skin. The latter, however, concern functional rather than structural
properties. Wrinkling, sagging, two facets of aging skin did not
show any seasonal influence. Such findings are not surprising for
two major reasons. On the one hand, skin aging is a rather slow
process, more easily evidenced in year’s decades than months. On
the second hand, structural changes such as sagging and wrinkling
clearly originate in alterations in dermis, a tissue with a slow
turnover [22], i.e. about 3–5 years. It is likely that only subtle,
Table II Description of test site for clinical assessments
Clinical sign Test site
Inter-ocular wrinkles
Crow’s wrinkles
Underneath eye wrinkles
Forehead wrinkles
Ptosis of lower part of the face
Dropping of the upper outer eyelid
Eye bags
Neck sagging
ª2011 The Authors
ICS ª2011 Society of Cosmetic Scientists and the Socie
´te
´Franc¸aise de Cosme
´tologie
International Journal of Cosmetic Science,1–7 3
Influence of season on some skin properties H. Qiu et al.
progressive and slow dermal alterations will cause the hallmarks of
an aging skin on subsequent years.
From practical and applied aspects, this result has important
consequences. First, it implies that instrumentally and/or clinically
proven efficacy of anti-wrinkle treatments (either cosmetic or
dermatological) over a 2 or 3 months period can hardly be related
to spontaneous improvements in the cutaneous tissue. Second, that
anti wrinkle testing (lasting less than 6 months) can probably be
carried out at any season of the year.
Some skin functions are, however, influenced by the two peak
seasons. Although with weak amplitude, the skin logically darkens
in summer. The density of hyper pigmented spots, clearly increas-
ing with age (plateauing at the 60s), shows a trend towards
increase in a 6-month period, but not significant. This is likely
Inter-occular wrinkles
0
1
2
3
4
5
6
7
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80 18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–8018–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Skin atlas grading
Winter
Summer
Crow's feet wrinkles
0
1
2
3
4
5
6
Age group
Skin atlas grading
Winter
Summer
Underneath eye wrinkles
0
1
2
3
4
5
6
7
8
9
Age group
Skin atlas grading
Winter
Summer
Forehead wrinkles
0
1
2
3
4
5
6
7
8
Age group
Skin atlas grading
Winter
Summer
Figure 2 Absence of alteration with season in wrinkles by clinical assessments.
Ptosis of the lower part of the face
0
1
2
3
4
5
6
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Skin atlas grading
Winter
Summer
Drooping of the upper outer eyelid
0
1
2
3
4
5
6
Age group
Skin atlas grading
Winter
Summer
Eye bags
0
1
2
3
4
5
6
Age group
Skin atlas grading
Winter
Summer
Neck sagging
0
1
2
3
4
5
6
Age group
Skin atlas grading
Winter
Summer
Figure 3 Absence of alteration with season in sagging by clinical assessments.
ª2011 The Authors
ICS ª2011 Society of Cosmetic Scientists and the Socie
´te
´Franc¸aisedeCosme
´tologie
International Journal of Cosmetic Science,1–74
Influence of season on some skin properties H. Qiu et al.
linked to the slow turnover of melanocytes. However, their appar-
ent melanin content expressed in Mexameter
values appears sig-
nificantly correlated with age (P< 0.0001) (Fig. 13). It seems
increasing during summer by an almost constant value (approxi-
mately 50 units) in all subjects. Does such constant increase, at all
ages, illustrate a true increase in melanin synthesis, or simply an
increased photo-oxidization of pre-formed melanins, previously
shown to be mostly UVA-induced [23, 24]? Lack of a third exami-
nation of subjects in the following summer unfortunately prevented
us from checking for a possible return to previous values.
Although Chinese women, at comparable ages, show a lesser
sebum production than women from other human sub-groups
55
60
65
70
75
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Lightness
Winter
Summer
Figure 4 Skin tone parameters lightness alterations with season
measured on Chromasphere
images.
22
24
26
28
30
32
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Chromaticity
Winter
Summer
Figure 5 Skin tone parameters chromaticity alterations with sea-
son measured on Chromospheres
images.
0
1
2
3
4
5
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Number of pigmented spot/cm
2
Winter
Summer
Figure 6 Number of pigmentary spots alterations with season
measured on Chromasphere
images.
0
50
100
150
200
250
300
350
400
450
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Melanin index on pigmented spot
(A.U.)
Winter
Summer
Figure 7 Melanin index of hyper pigmented spots alterations with
season measured by Mexameter
.
0
50
100
150
200
18–27 28–35 36–42 43–50 51–57 58–65 66–72 72–80
Age group
Number of active sebaceous
follicles/cm
2
Winter
Summer
Figure 8 Absence of alterations with season on number of active
sebaceous follicles on forehead area (data from Sebutape
measure-
ments).
0
20
40
60
80
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
µg/cm2/30 min
Winter
Summer
Figure 9 Sebum excretion rate alterations with season on fore-
head area (data from Sebumeter
measurements).
ª2011 The Authors
ICS ª2011 Society of Cosmetic Scientists and the Socie
´te
´Franc¸aise de Cosme
´tologie
International Journal of Cosmetic Science,1–7 5
Influence of season on some skin properties H. Qiu et al.
[20], they clearly show an increased sebum production during
summer. Apart from physiological reasons, i.e. hormonal, the
sebum output has been previously shown to be temperature depen-
dent [25, 26]. The density of active follicles appears to be unaf-
fected by seasonal change, which is in agreement with previous
findings, only showing a circadian rhythm [27], as evidenced by
the Sebutape
technique. This can be understood since structure
does not change during two season.
With regard to skin hydration, two different techniques con-
firmed the well-known winter and age-induced dryness. Summer,
with increased sweating and ensuing increased availability of
NMF’s [28], leads to higher hydration state. In addition, the
increased sebum supply during summer is likely prone to provide
to both epidermis and the stratum corneum an increased level of
free glycerol, a very efficient skin moisturizer, released by the
microbial lipases, highly active on the human face [29]. From a
technical viewpoint, the inverse correlation of the two techniques
used is an important fact to pinpoint. Corneometer
detects hydra-
tion in the deeper regions of the stratum corneum through propa-
gation of micro range currents. As for Skin Chip
, the contact of
the probe only affords a quantified ‘vision’ (grey levels) of the
hydration state in the superficial and ultimate layer of the Stratum
Corneum. The strong inverse correlation of values given by the
two instruments is of high importance. It implies that a dry superfi-
cial layer of the Stratum Corneum reflects less hydrated deeper
regions of this structure.
In this regard, although skin is clearly an organ adaptive to
stress of all natures, its own regulation of hydration faces a strange
paradox. The supply of moisturizing factors, either NMF or others,
should occur at the most needed season, i.e. winter, where cold
(and possible associated air dryness in some regions) seriously
impacts the hydration state of the skin. Measurements of possible
changes in the skin barrier of volunteers (e.g. through Trans
epidermal Water Loss) were not included in our study. Previous
works have shown the skin barrier function is affected by circadian
cycles, hormonal changes (along the feminine cycle), weather
conditions, etc. as reviewed in a landmark paper [30]. These likely
occurred during a 6-month period. The skin surface measurements
used in our studies (Corneometer, SkinChip) partly integrate such
possible changes, assuming that skin surface conditions reflect the
physiological states of deeper epidermal layers.
All together, this study shows that only slight functional
changes occur in skin during a 6-month period, as indicated by
the results at two marked peaks of the year. Whether these minor
events may be provisory, or cumulatively contribute to the global
skin aging process over the course of life still remains a key issue.
To sum up, over a 6-month period, the skin of Shanghaiese women
shows some functional changes. But age does not.
Acknowledgements
The authors would like to deeply thank all those who contributed
in this study, and particularly Saint-Leger Didier, Zhang Yanlu,
Sheng Fan, Yan Xiaojun for their help to achieve this paper.
40
45
50
55
60
65
70
75
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Hydration (A.U.)
Winter
Summer
Figure 10 Hydration alterations with season measured on cheek
area with Corneometer
.
80
90
100
110
120
130
140
150
18–27 28–35 36–42 43–50 51–57 58–65 66–72 73–80
Age group
Dehydration (A.U.)
Winter
Summer
Figure 11 Hydration alterations with season on cheek area mea-
sured Skinchip
.
0
50
100
150
200
250
15 25 35 45 55 65 75
Corneometer®
N = 708
R = 0.67
P < 0.0001
Skin chip ®
Figure 12 Inverse correlation between Skinchip
and Corneome-
ter
values techniques for all age groups.
0
100
200
300
400
500
600
18 23 28 33 38 43 48 53 58 63 68 73 78
Age
Melanin index of pigmented spot(A.U.)
N = 354
R = 0.43(summer)
R = 0.48(winter)
P < 0.0001
Summer
Winter
Figure 13 Correlation of melanin indexes with age. A rather con-
stant increase from winter to summer.
ª2011 The Authors
ICS ª2011 Society of Cosmetic Scientists and the Socie
´te
´Franc¸aisedeCosme
´tologie
International Journal of Cosmetic Science,1–76
Influence of season on some skin properties H. Qiu et al.
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Influence of season on some skin properties H. Qiu et al.
