April 27, 2010

UK: Let the sunshine in

. LONDON, England / The Times / Life & Style / Health / April 27, 2010 Our fear of skin cancer is blinding us to our need for sunlight. Bring on the rays . . . By John Naish “Sunlight is like a good champagne,” wrote Sir Henry Gauvain, an eminent British surgeon in the 1920s. “It invigorates and stimulates; indulged in to excess, it intoxicates and poisons.” Sadly in the UK in recent years our attitude to the sun has leant distinctly towards the latter state. Thanks to the insistent focus on the rise of skin cancer and our love affair with the tanning salon we are constantly exhorted to cover up at all costs and slather ourselves with factor 50 even in the shade. Photo courtesy: British Skin Foundation In fact, the risks of shunning life-giving sun were highlighted last week by research linking lack of sunlight to higher rates of prostate disease in northern countries. Poor exposure to sunshine can lead to vitamin D deficiency, which may increase prostate cancer risk, suggest scientists at Idaho State University. Lack of vitamin D is blamed for many other illnesses, from heart disease to osteoporosis. The obvious answer is to swallow supplements — and this month, the US Government said that most American children should do so. Photo by courtesy: Idaho State University But a raft of new research shows that to stay healthy and sane, we actually need full-spectrum sun rather than supplement pills. Sunshine is far better for us than we think. We evolved to absorb healthily moderate amounts of full-spectrum sunlight, and not only for its vitamin D-producing powers. For example, an important study this month indicates that the ultra-violet part of sunlight plays a bigger role than vitamin D in limiting multiple sclerosis. The disease is more common in the north than the tropics, so researchers had blamed the rise of MS on lack of vitamin D. A new study by Hector DeLuca, a biochemistry professor at Wisconsin-Madison University, confounds this. When people have high blood-levels of vitamin D, they also have high blood-levels of calcium. But DeLuca found that people at the Equator have low blood calcium and hence low vitamin D. So what is going on? Photo credit: madison.com DeLuca’s tests reveal ultra-violet light as the critical factor. His studies show that exposure to it reduces the symptoms of MS. The same sort of effect may also occur in diseases such as kidney cancer and non-Hodgkin’s lymphoma, which are lower in men who work outdoors — even in Britain. “We are looking to identify compounds produced in the skin that might play a role,” Deluca says in a paper published by the Proceedings of the National Academy of Sciences. The work may create new types of light therapy, especially if research finds specific beneficial wavelengths in sunlight. Scientists are also beginning to reveal sunlight’s benefits for our brains. Last month, research reported how modern adolescents are increasingly sluggish because they spend too much time indoors. “They miss out on essential morning light needed to stimulate the body’s 24-hour biological system, which regulates the sleep-wake cycle,” says Mariana Figueiro, of the Lighting Research Centre at Rensselaer Polytechnic Institute in New York state, who led the study. Exposure to morning short-wavelength blue light is crucial to our body clocks, Figueiro says. It helps our bodies to time the release of the hormone melatonin, which signals when to sleep later on. Figueiro got a group of 14-year-olds to wear glasses that blocked blue light. By the end of the five-day study, they were going to bed an average of half an hour later than usual. “Melatonin onset was delayed by about six minutes each day,” Figueiro says. Lack of sunlight has physical effects on kids, too. The Centre of Excellence in Vision Science at the Australian Research Council last year found that those who spend most of their day indoors, have far more “high myopia” — severe short-sightedness that has a 50-50 chance of blindness in middle-age. The researchers think the neurotransmitter dopamine is involved. It inhibits the excessive eyeball growth that causes myopia. Sunshine causes the retina to release more dopamine. Sun deprivation is not just an issue for teenage computer addicts. British adults dedicate less than 30 minutes in an average day to outdoor activity, says the Government’s UK 2000 Time Use Survey. Urbanisation, long work days and the tendency to sit gazing at screens indoors are all linked to the emergence of conditions such as malillumination syndrome (MIS), which involves depression, fatigue and aggression. The problem is not so much an illness, more a natural adaptation. When we deprive ourselves of sunlight, the pituitary gland in the brain is stimulated less. Our brains respond as if they are in the depths of a dark, perilous winter and prompt us to adopt survival tactics: grab more sleep, stay inside, be less sociable and eat whatever is available. Lack of sunlight interferes with the hormone leptin, which tells us when the stomach is full. We feel compelled to eat more, while exercising less. We pile on pounds. A University of Aberdeen study of 3,100 women in the northeast of Scotland, where one in five is overweight, found that the clinically obese have 10 per cent less vitamin D than those of healthy size. Dr Helen Macdonald, of Aberdeen University, says “The link is significant. We think obese people are not getting enough sunshine.” Sun exposure also helps to regulate two mood-controlling hormones, melatonin and serotonin, which play a crucial role in depression and seasonal-affective disorder. Levels of feel-good serotonin particularly dip in winter. Research by Lance Workman, a biological psychologist at Bath Spa University, suggests that more than 90 per cent of people feel more joyful when they enter periods of increased sunlight. So if we want to be happily efficient office bunnies, we need to get out more. However, the average UK lunch break has shrunk to 27 minutes (if we take one at all). Rather than taking sandwiches to the park, we gobble antidepressants indoors. For a solution we may be inspired by our great-grandparents’ passion for heliotherapy — or sunshine therapy. This was popularised in the early 1900s by a Swiss doctor, Auguste Rollier, who founded his work on discoveries that solar radiation could help to treat smallpox. Rollier opened solaria, with south-facing balconies and retractable roofs, across Switzerland. Soon the sun was touted throughout Europe as a balm for lupus, cuts, burns, arthritis and nerve damage. Tans became trendy. In Twenties Britain, respected physicians formed the Sunlight League to lobby for sun-therapy to become central to public health. They believed that “the practice of air bathing” gave greatest benefit — nudism was born. So, too, were lidos — open-air swimming pools — the first in Hyde Park, then they spread across England. By the Second World War, the craze had died down. Newly discovered antibiotics worked better against germs. Doctors were learning how excess sun did more harm than good. Sir Henry Gauvain, Britain’s leading heliotherapist and tuberculosis specialist, foresaw the problem in 1922. Now, thanks to new appreciation of sunlight, the balance needs redressing in healthy moderation. A few are starting to suggest that we should rethink our vampiric paranoia. Dr Veronique Bataille is among a group of scientists who report in the journal Nature Genetics, that the sun’s link with skin cancer has been overstated. “There has been so much effort put into telling people about the damaging effects of ultra-violet light from sunshine, many now take extreme measures by wearing factor 15 moisturisers all year round,” she says. “People do need a bit of sunshine to stay healthy.” After a long, miserable winter, what more excuse do we need to lighten up and brighten up? Decent exposure How much sun is sufficient to ensure we gain the benefits of full-spectrum sunlight? Advice varies — and is all dependent on the time of year, the weather and the lightness or darkness of our skin. The British Association of Dermatologists has issued guidance with the National Osteoporosis Society that recommends that we should get 15 to 20 minutes of sun exposure a day. But Bevis Man, of the British Skin Foundation, says that we should learn to judge our own limits of safe exposure: “It’s about being aware and literate about your own skin,” he says. “People with light skin should not stay in the sun as long as others with darker skin. The main thing is not to burn. I suggest people err on the side of caution and avoid being in the sun between 11am and 3pm. We should get into the habit of reading the UV-light forecasts.” The Met Office website carries a daily UV forecast, in which the scores go up to 11 — 1 and 2 are the lowest and you need not take precautions; from 3 to 5, you should seek shade in the midday hours and wear sunscreen; from 8 to 11, stay indoors during the midday hours but outside always wear a hat, sunscreen and shirt. The Met Office says the solar index does not exceed 8 in the UK. [rc] Copyright 2010 Times Newspapers Ltd. Illustrative photos and links added by Seniors World Chronicle