Sun Protection in Daily Products Alters Behavior

Mar 28th, 2016

Katerina Steventon, Ph.D., Independent Skincare Consultancy East Yorkshire, UK

The universal desire for a suntan continues to decrease year after year. This is due to research into the harmful effects of the sun being widely publicized and accepted by both the public and the skin care industry.

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In the European Union, sunscreen products are considered cosmetics and their effectiveness tested in vivo or in vitro to determine four effectiveness indicators: the Sun Protection Factor (SPF), the UVA Protection Factor (PF-UVA), the SPF/PF-UVA ratio and the critical wave length. When used correctly, sunscreen products protect us from sunburn as well as photo-aging.

The once clear boundaries between skin care and sun-care product categories are now less well defined; daily moisturizers contain SPF 15 protection and suntan lotions often include anti-aging claims. However, “a product for the beach will always be recognized as such, even if it contains additional, e.g., anti-aging ingredients; and a face care cream with SPF 20 still remains in the bathroom. Consumers will know the difference and having sun protection included in day care formulas is a good development,” said Karl Lintner, Ph.D., a consultant to the personal care industry.¹

Appealing to Vanity Promotes Daily Sun Protection

The decision to incorporate SPF into face creams and makeup began more than 10 years ago. Nowadays, SPF 15 in a day moisturizer is the norm. However, UVA radiation also has detrimental effects on the skin; it induces molecular, cellular and clinical damage.

Offering a wide spectrum of protection is essential as daily broad-spectrum sunscreen can slow photo-aging in as little as four years in middle-aged adults. Young people respond better to anti-aging than anti-cancer messages and visual examples of aging are particularly effective in motivating teens to avoid indoor tanning and pursue consistent sun protection.²

Daily use of sunscreen significantly reduces lifetime UV exposure to the face; the most important factor is to begin regular use early in life. The SPF and spectral profile of the product is of lesser importance, as is whether daily use is confined to the summer months rather than year-round.³

Topical application of a daily moisturizer with broad-spectrum sunscreen prevents UVA radiation-induced transcriptional expression of genes, which are directly linked to skin aging (i.e., matrix metalloproteinase-1). These genes also reflect the antioxidative stress defense response (i.e., catalase, superoxide dismutase and glutathione peroxidase). The protection provided by products with different SPF, but the same UVA-PF is similar, which emphasizes the importance of high UVA protection to maintain unaltered essential biologic functions.⁴

Holiday Behavior Differs from Day-to-day Use

The incidence of cancer is rising with national differences across Europe. Although the incidence of skin cancer is increasing, estimates reveal 45% of all preventable cancers worldwide are skin cancers. The effect of the behavior on UV exposure may help explain the higher skin cancer incidence among Scandinavians compared with other European populations.

When Danish and Spanish sun-seekers were observed during a sun holiday in Spain, the Danish sun-seekers were outdoors significantly longer, receiving significantly higher percentages of ambient and greater accumulated UV doses than Spanish sun-seekers.⁵

In the Scandinavian population, sun exposure habits and the propensity to undertake sun protection differ between individuals depending on age, gender and level of education. Swedish women report more frequent sun-tanning and sunbed use, but also more extensive sunscreen use.

Older age is linked to a low level of sun exposure and high level of protection. High educational levels and sensitive skin type are associated with higher readiness to increase sunscreen use; therefore sun protection advice should be personalized according to the individual patient situation and capabilities.⁶

However, campaigns are needed to encourage sun protection as even populations with high levels of sun exposure show a lack of care. A survey of Latin Americans reported that although they are aware of the risks of excessive sun exposure and skin cancer prevention, they have not yet incorporated appropriate sun protection measures into their daily habits.⁷

Applying Enough?

In parallel to our increased understanding of the UVA irradiation-caused damage, advances have been made in modern sunscreen formulation. A variety of UVA filters are now available for formulators to combine with UVB filters to reach high-level photo-stable protection, using a minimum concentration of active ingredients. Sunscreen efficacy tests conducted in vivo are done by applying the product at a rate of 2.0 mg/cm². In a real-life scenario, only the use of half of said amount has been reported, affecting both the SPF and PF-UVA, depending on the product type.⁸

Sun protection is a major concern, primarily for sun-seekers and outdoor workers. When estimating skin cancer risk, a geographically-adjusted questionnaire to estimate self-reported cumulative UV radiation exposure can help people with higher levels of exposure seek advice on photo-protective measure.⁹ Further, L’Oréal will launch innovative patches for monitoring UVB exposure and risk of sunburn later this year.¹⁰

Collaborative campaigns by healthcare authorities, cancer foundations and dermatologists should focus on population-tailored sun-safety education programs worldwide.¹¹