Here comes the sun
- Health & Social Care Research, Cancer, Ageing, Skin, Healthy living & wellbeing
By Martin Galler
VOICE Knowledge Exchange Intern
Sipping on a cocktail or enjoying an ice-cream-feet up, and soaking up the sun. You can’t beat a summer’s day sat in the garden. However, over recent years we’ve been repeatedly told that too much sun is bad for us; we need to stay out of it, seek shade, cover up, and douse ourselves in a thick layer of sun cream. Off the back of recent figures released showing skin cancer has increased 45% in the last decade, Cancer Research UK have reiterated this advice. And they’re right, too much sun is dangerous. UV rays from the sun can damage our DNA and lead to cancer. However, a lack of sun may also be bad for our health.
The sun is a key source of vitamin D production, and a lack of which has been associated with a range of disorders such as depression, osteoporosis, cardiovascular disease, diabetes, and cognitive decline. Worryingly, in the UK, vitamin D deficiency affects 30-40% of the population in the winter and around 10% in the summer.
Vitamin D isn’t the only health benefit that we get from the sun. UV rays also activate a molecule called nitric oxide, which plays an important role in a range of processes that keep us healthy. Furthermore, there’s evidence that nitric oxide might also be a significant factor in determining how long we live. As we grow old, the amount of nitric oxide in our bodies decreases, which scientists think might contribute to the ageing process. Studies have even shown that increasing the levels of nitric oxide in animals such as round worms can extend lifespan!
So why might this be? Well, nitric oxide has been established as having an important role in widening blood vessels in a process called vasodilation, enabling a good blood flow to vital parts of the body. If levels are depleted, as they are when we age, then the risk of cardiovascular disease increases. Amazingly, it has been demonstrated that just 20 minutes in the sunshine can lower blood pressure.
However, it isn’t just protection against cardiovascular diseases that nitric oxide is important for. Research has also identified that low levels can increase the risk of Alzheimer’s disease. Scientists in Italy found that lower levels of nitric oxide resulted in reduced vasodilation, and reduced blood flow to critical areas of the brain. Similarly, good blood flow is essential for protection against the risk of strokes.
The benefits of sunlight do no stop there. There is evidence that UV has a protective role against autoimmune diseases, such as inflammatory bowel disease, rheumatoid arthritis, and multiple sclerosis (MS). As with cardiovascular diseases, experts have found that many autoimmune diseases become worse in the dark winter months, and in parts of the world that receive less sunlight. Incredibly, by using UV, scientists have been able to delay the onset and severity of MS in mice.
So, what do we do? Do we head for the beach, embrace the sun, and risk skin cancer in the hope that we can ward off old age with the help of vitamin D and nitric oxide? Or, do we reach for the parasol and knotted hanky, and risk cardiovascular disease? A study in Sweden has attempted to answer this conundrum. In the early 1990s, nearly 30,000 Swedish women were asked about their health and sun exposure, with follow up interviews 20 years on8. They found that those who avoided the sun were more likely to die of cardiovascular disease, and on average died nearly 2 years younger! Their data even suggests that in terms of chances of dying, seeking shade is as bad for you as smoking!
However, this doesn’t mean it’s now alright to sit frazzling in the sun! Experts reckon 5-10 minutes (or slightly longer for darker skin) in the mid-day summer sun is enough to get our daily dose of vitamin D, keeping the risk of skin cancer to a minimum. And, despite the benefits of sunlight, it’s certainly not recommended that we become blasé with regards to sun protection.
Mad dogs and Englishmen go out in the mid-day sun…. but perhaps there’s method in their madness.
Have you used, or would you consider using UV or sunlight as a form of treatment? Do you feel better after being out in the sun? Does being in the sun affect your blood pressure? Get in touch and comment below.