The Census Bureau estimates that by the year 2030, nearly 40% of Americans will be over 65 years old. What’s more, that older population will also be more racially and ethnically diverse than it is today.

Skin in shades of brown is the new normal in the United States — and yet, there is little scientific information on how populations of different ethnicities respond to aging.

Neelam Vashi, MD, director of the Center for Ethnic Skin at Boston Medical Center, sought to address this scarcity of information in a new paper she published on skin aging.

The study amassed and examined 41 peer-reviewed published articles between 1970 and 2018 through PubMed that focused on the signs of skin damage, like skin discoloration, loss of collagen, and skin cancer, depending on skin type and ethnicity.

“Aging is inevitable, and each person will have a unique experience with how their skin changes as it ages,” said Vashi, who is also an associate professor of dermatology at Boston University School of Medicine, in a press release.

As the U.S. population lives longer, older skin is not only chronologically aging — what’s known as “intrinsic” aging — it’s also being exposed to more environmental factors, like Ultraviolet (UV) light, which can cause age-related skin damage (aka “extrinsic” aging), reports the Boston Medical Center.

Vashi’s research found that people of color are more prone to experience changes in skin pigmentation (dyschromia) over time.

Vashi’s research found that melanin is a key difference in light and dark skin types, and that people of color are more prone to experience changes in skin pigment (dyschromia). But, different ethnicities each have their own unique skin-aging factors.

For instance, African-Americans tend to have thicker skin, which results in a delay in the appearance of wrinkles when compared to Caucasians, whose thinner skin loses elasticity more quickly. And those of East Asian descent are more likely to experience hyperpigmentation, while wrinkles often don’t appear until later in life. Similarly, people with Hispanic heritage experience fewer wrinkles in the early part of the aging process.

The one thing everyone can do to help prevent skin aging is to limit UV exposure. “Skin cancer is the most common type of cancer in the U.S., and using sunscreen is an extremely important practice to protect your skin,” Vashi said.