Relatively little is known about ethnic specificities in adolescent skin, although the research division of French luxury products group Moet Hennessy Louis Vuitton (LVMH) is focusing a high percentage of its efforts on understanding modifications in the skin as young people change from being children to adolescence and adulthood.
LVMH Recherche organised a symposium - entitled "From adolescent to adult skin: Japanese and European specificities" - in Tokyo, Japan on 29 May, with dermatology experts from France and Japan presenting the latest findings on changes in human skin, consumer data on Japanese skin care and attitudes towards beauty. An understanding of these issues will enable cosmetics companies to develop specific and innovative products worldwide, said Dr Frédéric Bonté, director of scientific communication for LVMH Recherche, which has its laboratories in the town of Saint Jean de Braye, southwest of Paris. That said, speakers outlined clear differences in attitude and skin character in European and Asian markets, which have to be considered by cosmetics multinationals.
Japanese skin
The first speaker was Dr Katsuko Kikuchi, of the department of dermatology at Tohoku University's graduate school of medicine. Kikuchi has carried out a two-year clinical and biophysical study into the skin characteristics of Japanese women between the ages of 13 and 22, subjecting the women to measurements of high frequency conductance with a skin surface hygrometer, capacitance, transepidermal water loss, skin surface pH levels, casual skin surface lipid levels and skin colour.
Her team assessed sebum secretion, took examples of corneocytes, mapped skin surface contours, evaluated ridges and furrows in the skin, took microscopic pictures and assessed follicular plugs.
With the women divided into three age groups - 13-14, 16-18 and 19 into the early 20s - the initial study showed that the hydration state of the stratum corneum increased with age, while there was no statistical difference in transepidermal water loss values between the three groups.
Sebum secretion increased with age, while significantly lower values of skin surface lipid level were observed in the youngest age group.
Skin surface pH levels were highest in the middle age group, while the research also showed a significant increase in skin luminosity with age. At the same time, there was a marked decrease in yellowness skin values with age. The youngest subjects had a lower score of papules as well as fewer follicular plugs on the medial cheek, but no significant differences in the ridge and furrow patterns of the skin.
Most of the subjects expressed concern over acne, with 64% of the youngest age group having acne and 74% of both the other groups experiencing the complaint. Oily skin also increased with age, with skin getting oily around the age of 13, and that concern fading as test subjects reached their early 20s, leading to them more frequently using a moisturiser. The research also showed that more than 50% of young females in Japan use a facial sunscreen.
In the follow-up research, two years later, no significant difference was noted in high frequency conductance or capacitance in the youngest age group, although transepidermal water loss values tended to increase with a significant decrease in the size of corneocytes. Sebum secretion had risen, as had luminosity values. Anisotropy and follicular plugs were more frequent. For the 16-18 age group, the outstanding difference was in the increase in luminosity values, while redness and yellowness skin values had significantly decreased. The research on the oldest age group could not be completed because most of the women had moved away from the area.
In conclusion, Kikuchi said, stratum corneum hydration of facial skin was low, with low sebum secretion before puberty. During adolescence, however, follicular plugs and papules increase, along with sebum secretion and transepidermal water loss. The reason for this, she suspects, is an increase in epidermal and follicular keratinization in adolesence, while for a dermatologist, the emphasis must be on encouraging young women to use a moisturiser before adolescence because young skin is drier.
In response to a question, Kikuchi said that young Japanese women use more sunscreen than women in Europe or the US as they are already preoccupied with the possibility of developing age spots and wrinkles.
European skin
The next speaker was Dr Nadine Pomarède, who examined the main skin problems that adolescents in Europe experience. Acne is the largest problem, she said, with as many as 95% of 13-18 year olds affected to varying degrees. Nearly 20% of dermatologists' cases are acne releated, with females more frequently seeking treatment than males.
Sebum secretion is the major cause of acne in people before the age of 20, also affecting the size of pores. Skin is also uncomfortable at this phase of a young woman's life, Pomarède said, due largely to the inappropriate application of cosmetics, which is why teenagers require specific cosmetics. According to studies, some 53% of teenagers with acne are unhappy; among those who have not had acne, there is an even more negative perception of the complaint.
Blemishes are concentrated on the face and are visible to everyone at a time when a young person's appearance is increasingly important, she emphasised, with acne having a major impact on quality of life.
Pomarède said more needs to be done in terms of educating young people about acne and how they might be able to avoid it, including through advice on cosmetics that are designed not to block pores and cause spots and diet. A 2002 study suggests that high levels of sugar in the Western diet leads to increased sebum secretion. She also suggested that dermatologists encourage young people to use sunscreens formulated for young skins while stress is another cause of acne.
"All young people want to have perfect skin and each mark that they have is uncomfortable to them," she said. "We need to be able to treat these scars on the surface of the skin."
Attitudes towards beauty
Kaori Amaha of the IPSOS marketing consultancy detailed the results of a survey concerning young people's attitudes towards beauty, to describe their skin type and determine the amount of skin care products they use. Some 700 women aged 13-21 were questioned in January, with most expressing the belief that they have dry skin, but older women saying they have combined oily facial skin.
Most Japanese women - in contrast to European women - say their skin is not sensitive, but their main concern is acne, followed by dryness, visible pores and oiliness. By age group, younger females have the fewest concerns about their skin; that changes at around the age of 16. A majority of the women said their skin quality has deteriorated in the last year, with age spots and wrinkles unanimously seen as the first sign of ageing, probably around the age of 30.
Around 80% of the study subjects use a facial cleansing product and 77% use skin care products such as moisturisers or lotions. The older age groups use more facial cleansing products, particularly elaborate items such as masks, scrubs and cleansing milks. Some 76% of women also use some form of sun block, with the SPF level increasing with age. Make-up is used by 62% of women, mostly those over the age of 16, with special attention paid to the eyes.
More generally, the respondents to the survey do not fear ageing yet but are very concerned about how others see them. They all want to be attractive and few are satisfied with the way they look. Most do not want to have tanned skin but only half equate fair skin with beauty. Few demonstrate any brand loyalty when it comes to cosmetics and they prefer to be experimental, she concluded.
Research & development
The final presentation came from Eric Perrier, vp of R&D at LVMH Recherche Parfums et Cosmetiques, who said the latest studies about the skin of adolescents allow his company to open new programmes of research for this sector of the market.
On the one hand, he said, oily skin, acne and pore size are the most pressing concerns for young Asian women, and far more so than the quest to find ways of fighting wrinkles. But on the other hand, cosmetic products try to complement traditional medical treatments and are based on intensive use of physical scrubs, which can induce abrasion, the use of antimicrobials to reduce bacteria but also induce strong disequilibria in skin microflora, and the use of alpha or beta hydroxy acids to induce stratum corneum renewal.
These cosmetic products, he said, are a very harsh way of taking care of the skin of younger people and instead cause more dryness, reactivity and increased disequlibria. That does, however, open the way for new developments in cosmetics.
One key requirement would be to preserve pH at a physiological level, around 5 or 6, for any cosmetic product for young skin, while short-chain fatty acids should be avoided in cosmetic formulations to avoid microbial growth in anaerobic conditions. The overuse of glycols in formulations should also be reduced, he suggested, while the use of very strong cosmetic active compounds should be avoided as they may perturb the structure, organisation or microbial ecology of the skin.
The cosmetics industry also needs to learn to make the use of cosmetics instinctive among young women, through attractive packaging and formulations, but also efficient and evident to use, he said.
Perrier concluded by stating that in the specific case of cosmetic products for adolescents, behaviour, fashion and even emotions during the use of cosmetic formulations will continue to strongly modify the way in which the researchers at LMVH develop new products.