Combing Through Sun and Pollutant Effects on Hair


Trefor A Evans, Ph.D., institute fellow at TRI Princeton and long-time C&T scientific advisor, offers his insights on the latest developments in hair science and what they mean to the cosmetic formulator.

C&T: What are the latest developments and trends in hair care of which cosmetic formulators should be aware? How should they act on them today? What should they expect to see coming in the next six to 12 months?

TE: As we approach the summer months, I wouldn’t be surprised to see more products addressing sun protection of hair. The very serious health risk associated with the sun’s rays on our skin is front-page news, and while any cosmetic impact on hair is trivial in comparison, there nonetheless appears to be a well-entrenched belief (and considerable scientific data) suggesting detrimental effects. The idea of sun protection for hair has been around the industry for some time—maybe its time has come.

C&T: We’ve known for a long time that exposure to UVA and UVB is bad for the skin, but more is becoming known about UV’s effects on hair. Please talk about what those effects are. What can cosmetic formulators do to help consumers protect their hair from UV exposure?

TE: Most obvious is the lightening of hair that occurs due to photo-chemical breakdown of melanin pigment. This may be desirable to those seeking natural highlights, while a source of considerable frustration for others. Melanin is nature’s sacrificial sunscreen—which is attacked and broken down in place of more important hair proteins. Therefore, blonde and grey hair, which are low in melanin, are more susceptible to photo-oxidation of these proteins, leaving the hair in a weakened state and with lessened sensorial properties.

In theory, deposition of sunscreens on the hair surface should diminish exposure to these harmful rays. Yet, there would seem to be a balance—where higher deposition should lead to increased efficacy, but potentially at the expense of creating an oily feel. As always, a good conditioner will help mask/alleviate many symptoms of hair damage.

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