Do dark and olive skin tones age slower than light skin tones: fact or fiction?

Skin aging is a natural phenomenon that affects every individual, typically beginning around the age of 25, an age when the skin starts to show the first signs of sagging and loss of elasticity. Subsequently, fine lines, wrinkles, and pigmented spots gradually appear on the skin. Numerous factors, both intrinsic and extrinsic, influence skin aging, some of which are directly related to phototype.

• Darker skin synthesizes more melanin than lighter skin.

  UV rays, which generate free radicals that damage skin structures, are the primary cause of skin aging. To protect itself, the skin produces melanin, a pigment that absorbs ultraviolet rays, acting as a natural sunscreen. Melanin is also responsible for skin color. Overall, darker skin has larger melanosomes, the specific organelles of melanocytes where melanin is produced, dispersed individually and contain more melanin than the smaller, aggregated melanosomes containing less melanin found in lighter-skinned individuals. This higher melanin content in darker skin and their pattern of melanosome dispersion provide better protection against photoaging. Studies have indeed shown that black epidermis offers, on average, an SPF of 13.4.

Although darker skin tones are naturally more protected from photoaging than lighter skin tones, they also require a sunscreen when exposed.

• The dermis of darker skin is thicker than that of lighter skin.

  The flexibility and elasticity of the skin primarily depend on the characteristics of the dermis, the middle layer. Its progressive atrophy over time contributes to skin sagging and the appearance of wrinkles. However, studies have shown that the thickness of the dermis is proportional to the degree of pigmentation, meaning that individuals with darker skin have a thicker dermis than those with lighter skin. It has also been suggested that the epidermis of darker skin consists of more cellular layers and that their stratum corneum, or outermost layer, contains a higher lipid content than that of lighter skin. Thus, darker skin has greater resilience and skin extensibility.

• The collagen and elastin in darker skin are more protected than those in lighter skin.

  The collagen and elastin are essential proteins for maintaining the firmness and elasticity of the skin. However, over time, their production slows down. Moreover, as the years pass, the fibers become rigid, fragmented, and disorganized. Studies suggest that skin pigmentation may play a role in resisting the degradation of collagen and elastin. One study focused on the evolution of elastic fibers in the skin of women of different complexions, aged over 40. This study showed that the collagen and elastin fibers in darker skin were, for the most part, intact, while they had largely disappeared in lighter skin. Individuals with a darker phototype therefore seem to benefit from some protection against the natural degradation of collagen and elastin, which contributes to maintaining the suppleness of their skin.

  Furthermore, other studies have shown that the dermis of individuals with dark skin contains more active fibroblasts than that of light skin. This increased activity leads to the formation of compact and more parallel collagen bundles, allowing dark skin to maintain its structural integrity and youthful appearance longer than light skin. Additionally, dark skin has more numerous, larger, and more nucleated fibroblasts, meaning they have more nuclei. Their division potential is therefore lower than that of fibroblasts in light skin, which means their activity duration is longer.

• Darker skin types are believed to produce more sebum than lighter skin types.

  Sebum is an oily substance produced by the sebaceous glands and is a component of the hydrolipidic film present on the skin's surface. This film acts as a veil to protect the skin from external aggressions and also to limit water loss, thereby reducing the visibility of dehydration fine lines. According to some sources, darker skin tends, in general, to produce more sebum than lighter skin. Indeed, it would have a greater number of sebaceous glands and these would be larger in size. Furthermore, darker skin would have larger pores than lighter skin, which would lead to a better diffusion of sebum on the skin's surface. However, more studies are still needed on this subject.

Several specific characteristics of dark and medium skin tones contribute to their slower aging compared to light skin tones. However, this does not mean that they can do without a skincare routine tailored to their needs.