Sin, cos, and the truth about tan: Melanin’s complex relationship with the sun

“I never really worried about protecting my skin from the sun. ‘Black don’t crack’ wasn’t a phrase I really heard a lot growing up. If anything, it was ‘black don’t burn.’” Leah Donella, senior editor at NPR, said.

This belief is almost universal. Ask people in London or Lagos, Kingston or Kampala, whether they need sunscreen, and the answer is often the same - “We don’t burn, so why bother?”

Melanin, the pigment that gives Black skin its depth and beauty, is treated as a lone protector. The medical reality of this is more complicated and more urgent than the myth suggests.

Melanin produces hair, eye and skin pigmentation, and offers some protection against sunburn-causing UVB rays. The pigment scatters and absorbs ultraviolet radiation, converts it into heat, and quenches the free radicals generated by UV rays in skin cells. Although this is significant, the natural sun protection factor (SPF) equivalent of melanin in darker skin is estimated at around 13. This is less than half the minimum SPF 30 that dermatologists recommend for daily protection. 

Caucasian skin, by comparison, offers a natural equivalent of roughly SPF 3 to 4.  

SPF usage across communities 

Sunscreen use is low overall, but is lowest amongst Black communities. A recent study conducted by Face The Future found that only one in six people in Britain applies SPF daily. Within this statistic, one in two Black British people shared that they don’t apply SPF at all, even in the summer months. 

This ‘sunscreen gap’ is largely driven by a lack of perceived skin cancer threat from UV exposure. That perception has been reinforced, sometimes unintentionally, by statistics that look reassuring on the surface. The lifetime risk of melanoma for Black people in the UK is approximately 1 in 1,000, compared to 1 in 38 for white people. However, the lower incidence figure obscures what happens when Black people do develop skin cancer.

The five-year melanoma survival rate for Black patients is 74.1%, compared to 92.9% for white patients.  Black patients are around three times more likely than their white counterparts to die within five years of a melanoma diagnosis. The principal driver of this is not biology, but rather, timing. Black patients are three times more likely to receive a late-stage melanoma diagnosis, by which point treatment options are limited, and prognoses worsen.

The myth of sunburn immunity feeds directly into this. Research suggests that both patients and physicians have believed non-white people to be effectively immune to common skin cancers.  Dermatologists have been found to be less confident in identifying skin conditions on darker skin compared to lighter skin, and clinicians have historically been less alert to suspicious lesions in Black patients. The result is a system that misses cancer earlier because it is not looking for it.

A scale built for some, not for all 

Part of the structural problem sits at the very foundation of dermatology’s classification tools. The Fitzpatrick skin type scale is the system dermatologists have used since 1975 to categorise patients by skin tone and UV reactivity. It was originally developed for a psoriasis trial involving white patients being treated with phototherapy. The scale underrepresents darker skin colours and has led to a lack of recognition for the diversity of darker skin tones. 

The consequences of that inadequacy extend into the research literature, clinical training, and now, artificial intelligence. 

Fewer than 5% of dermatological images in medical textbooks represent dark skin tones, and images of the cancers most commonly associated with darker skin tones are rarely depicted.  When Google image searches for skin cancer signs and prevention are analysed by skin tone, light skin tones comprise roughly 96% of results, whilst dark skin tones appear in around 4%.  

What clinicians learn to look for, and what patients learn to worry about, is filtered almost entirely through white skin.

Hot countries, cold statistics 

Black people living in or originating from high-UV environments, for example, across sub-Saharan Africa, the Caribbean, and South Asia, face elevated sun exposure over lifetimes. This is often without SPF as a routine part of skincare. 

Research into sun protection practices among Black African populations has found low uptake, with photodamage, immune suppression, photoaging, and cataracts all occurring across individuals of all skin types.

Squamous cell carcinoma (SCC) is particularly relevant here. Unlike melanoma, which is more commonly associated with sunburn in white populations, SCC in Black patients frequently develops in areas of chronic sun exposure. Mortality rates from SCC are disproportionately high in Black communities, with estimates ranging from 18% to 29%. 

In addition to this, Black patients remain underrepresented in major cancer drug trials. In the CheckMate-067 Phase III trial, one of the landmark studies in melanoma immunotherapy, no participants were Black. The treatments being developed, refined, and approved are not being tested on the patients that need them most.

The equation medicine got wrong

So, melanin is not the sole protector. It is a partial filter operating in a system, consisting of medicine, public health, and dermatological education, that was not designed with Black skin in mind. The lower incidence of skin cancer in Black communities is not evidence that protection is unnecessary; it is a baseline obscuring a mortality gap that should not exist.

Research suggests that even the modest reduction in UV-induced DNA damage offered by melanin, if matched by sunscreen use, could be extremely beneficial.

SPF is not a white person’s product. The absence of it, from medical research, from dermatological tools, from the skincare routines of millions of people who have been told they don’t need it, is a choice with consequences that are already visible in the data.

The equation has always been solvable. The question is whether the system is finally willing to do the math.