A dermatologist offers advice on protecting your skin

Sunburn is a sign that skin has experienced significant levels of damage. Ultraviolet light can change a person’s DNA structure, which can lead to cancer.
At the same time, choosing from the multitude of modern sunscreens can be overwhelming. Health & Medicine editor Nadine Dreyer asked dermatologist Bianca Tod what to look for in sun protection.
What are the dangers of too much exposure to the sun, especially in Africa?
People living in Africa are exposed to high levels of solar radiation. The continent includes a wide range of latitudes, as well as the Equator. Even the most northerly and southerly points of Africa experience significant levels of solar radiation. Altitude, weather patterns and other phenomena influence the intensity of this radiation.
People’s lifestyles also determine the level of solar radiation that they are exposed to. Do they work or socialise outside? How much does their traditional dress cover them up?
The sun has many beneficial effects, for example improving mood and contributing to vitamin D levels, but it is easy to overdose!
The immediate dangers include sunburn, dehydration, heat stroke and even changes to the immune system. Some of the long-term effects are eye damage such as cataracts, visible ageing and skin cancer.
Are people with dark skin at risk?
Melanin, which is the main skin pigment, offers protection to living tissues. The more concentrated the melanin, the darker the skin colour. So, someone with a darker skin has a greater degree of inherent protection against some of the negative consequences of sun exposure, compared to someone with light skin colour. This protection is not absolute and varies with the skin colour.
There are many types of skin cancer, but sun-related skin cancers occur far more commonly in people with light skin colours, especially people with blue eyes, and red or blonde hair.
But that doesn’t mean they don’t occur in people with darker skin colours, and we certainly see them in people with light brown skin. We occasionally see skin cancer in people with very dark skin. To what extent sun exposure drives these cancers is still not clear. This is an area where we need more research.
People with dark skin are more likely than people with fair skin to develop vitamin D deficiency if they have low levels of sun exposure. Lack of vitamin D has many side-effects. It can lead to fatigue, bone pain and muscle cramps as well as mood changes, such as depression.
People with dark skin colours are also more prone than people with light skin to develop uneven or blotchy pigmentation after sun exposure. Eye damage from the sun occurs in people with all eye colours.