The Benefits of Sunlight


Everyone feels better when the sun comes out, but sunbathing has had such a bad press for so long that the health benefits of getting out in the sun have been almost forgotten by a generation that now believes sunbathing is as bad for your health as smoking. It is true that the wrong kind of exposure to the sun will increase your risk of skin cancer, but the right kind of safe sunbathing can still make you happier and healthier.

For centuries, doctors and natural healers relied on something called Heliotherapy – using sunlight for healing – to mend wounds, treat bone diseases such as rickets or lung infections like tuberculosis (TB), and to simply help their patients rebuild strength after an illness – but all the known benefits of sunbathing were ignored when researchers began to link the alarming rise in the number of cases of skin cancer over the last 20 years with over-exposure to the sun.

The damage caused by staying too long in intense sunlight does increase the risk of skin cancer but safe sunbathing has been shown to help alleviate a host of problems ranging from chronic skin conditions including acne, eczema, and psoriasis. It can help build strong bones and teeth, lower cholesterol levels, prevent heart disease, and ward off depression. Even better, according to some health experts, sunshine may even prevent more cancers than it causes.

Stronger Bones & Teeth

Everyone knows you need calcium for strong bones and teeth, but to make sure the calcium you do eat can do its job, you also need a good supply of vitamin D, which protects against bone loss. Vitamin D is not really a vitamin at all but a hormone-like substance that the body can only make when it gets enough sunlight. Since 90% of westerners now spend 90% of their waking time indoors, the majority of people do not get enough exposure to sunlight to make enough vitamin D. The UK’s department of health says we need 400IUs (international units) of vitamin D a day to stop the body from leaching calcium from the bones. The trouble is, the typical British diet only provides, on average, 100 IUs per day. Also, the body is better able to use the vitamin D it makes itself than that which it gets from the diet. What all this means is that a growing number of people who are at risk of being deficient in vitamin D and thus also at risk of brittle bone disease.

Osteoporosis now affects one in every three women and one in every 12 men in the UK. Described by the World Health Organisation (WHO) as ‘the silent epidemic” there are often no symptoms until the first fracture, by which time you may have lost a third of your bone density. In women, the menopause can accelerate the problem because levels of the female hormone estrogen, which helps bones absorb calcium, declines. But all females naturally start to lose bone density from the age of 30 – so don’t think this is only a problem of middle age. There may be no symptoms until a bone has fractured and by the time you are at serious risk of osteoporosis, you may have already lost a third of your starting bone mass.

The World Health Organisation, (WHO), is now predicting that the number of hip fractures could increase six-fold to over six million by the middle of this century. This is why osteoporosis is being called an epidemic, yet one solution could be as simple and as free as safe sunbathing. In studies of elderly populations who have suffered a broken hip, up to 40% have been shown to be lacking in vitamin D. There are also more hip fractures in winter when bone density is at its lowest.

Enhanced Immunity

Sunlight triggers the body to make its own vitamin D, which is crucial not only for strong bones and healthy teeth, but for keeping the immune system healthy too. Studies have shown, for example, that exposing the body to sunlight or even ultraviolet light from an artificial source increases the number of white blood cells or lymphocytes. These are the body’s primary defense against the onslaught of an infection and are an important part of your immune response to the organisms that cause illness.

Vitamin D also plays a role in increasing the amount of oxygen your blood can transport around the body, which, in turn, will boost your energy levels, sharpen your mental faculties and give you an improved feeling of well being.

Less Cholesterol & Lower Blood Pressure

Few people realise that sunlight actually lowers blood cholesterol levels and so can be a powerful ally in the fight against the Western World’s biggest killer – heart disease. This works because the body needs the ultraviolet light in sunlight to breakdown cholesterol, which at high levels could otherwise block the arteries.

Both cholesterol, which is needed to make the sex hormones, and vitamin D are derived from the same substance in the body – a chemical called squalene, which is found in the skin. There is a new theory that in the presence of sunlight, this squalene is converted to vitamin D but in its absence, it is converted to cholesterol.

Sunlight can also affect blood pressure. Levels are higher during winter and lowest in the summer. The theory is that without enough vitamin D, triggered by exposure to sunlight, the body increases levels of parathyroid hormone. This hormone not only causes calcium to leach from the bones but also raises blood pressure, leading to a greater risk of cardiovascular disease.

Protection Against Cancers

Population studies have now shown how women living in less sunny regions in America have a 40% higher chance of dying from breast cancer than those living in sunnier parts such as Florida or Hawaii. It was reported that women who lived in sunny regions and who had high exposure to sunlight reduced their risk of this disease by up to 65%. This protective effect is believed to be linked to vitamin D, which has been shown in laboratory tests to inhibit cancer cell growth.

Not many people realise that the skin cancers or malignant melanomas that can kill develop most often on those body parts that are not usually exposed to sunlight – i.e. the back of the legs and the torso. Also, skin cancer rates are higher in less sunny parts of Europe than those closer to the equator. Again, nobody can explain why this should be so, but one theory is that sunlight works to stimulate the body’s own defenses against all cancers.

In the early 1990s, doctors who reviewed all the medical literature examining the health risks of exposure to the sun concluded that the benefits of moderate exposure outweigh both the risk of skin cancer and premature ageing. Their paper, which was called “Beneficial Effects of Sun Exposure on Cancer Mortality” was published in the US journal Preventive Medicine and reported that safe sunbathing would slash the number of deaths from breast and colon cancers in America by a third.

Better Mood, Better Sleep, Better Sex Drive

Sunlight also triggers the increased production of the feel-good brain chemical, serotonin – which, as well as controlling your sleep patterns, body temperature, and sex drive, lifts your mood and helps ward off depression.

The reason so many of us suffer from the winter blues or even a condition called Seasonal Affective Disorder (SAD) – which now affects 20% of the population – is that the body makes less serotonin in the winter. Popular prescription antidepressants such as Prozac work to increase serotonin levels in the brain and so does sunlight, which is why many SAD sufferers eventually resort to some artificial indoor light-box treatment.

One intriguing new and, as yet, untested suggestion is that during the summer, it is possible the body builds a kind of “sunlight memory bank” to help those of us living further from the equator through the darker winter months. In the UK, for example, you cannot make vitamin D from sunlight between the months of October and March because the UVB radiation with the right wavelength that is needed to achieve this is only present at ground level from April to September. This means you are dependent on the vitamin D store you have built up the previous summer. The theory then is that the amount of serotonin your body produces in winter will be directly related to the amount of exposure to sunlight you enjoyed the previous summer.

Another reason sunlight is so important to good health is that you can only get a quarter of the vitamin D you need from your diet. The rest must come from the sun. Also, as we get older, our bodies find it harder to absorb the vitamin D that does come from the diet.

Protection Against Multiple Sclerosis

Multiple sclerosis (MS) is a disease of the central nervous system. It happens when the myelin sheaths, which cover and protect the nerve fibers, are damaged, leading to symptoms such as tremors and even paralysis. The cause is not known but what scientists have noted is that exposure to sunlight in childhood appears to dramatically reduce the risk of this disease in later life.

In Switzerland, for example, MS is much more common at low altitudes than at high altitudes, where the intensity of ultraviolet radiation is much stronger. One theory is that greater exposure to bright sunlight in some way bolsters the immune system to prevent the damage to the nerve fibre sheaths that underlies this disease. Again, researchers cannot explain why this should be so, unless vitamin D is involved.

In Norway, there are far fewer cases of MS among coastal populations who eat more fish – an excellent source of vitamin D – than their inland counterparts. Also in Japan, where the diet again includes a large proportion of fish, there are lower than expected rates of this condition. But as we have seen, the body makes even better use of the vitamin D it produces itself, after exposure to sunlight, than the vitamin D it gets from food.

Safer Sunbathing

You do not need to burn or tan to get the exposure you need. Just 20 minutes of safe sunbathing a day is enough. The safest way to benefit from the healing powers of sunlight, say experts, is to build your exposure slowly throughout the year and to avoid burning by staying in the shade when the sun is at its most intense or you are on your holiday.

There are two types of burning rays, UVA and UVB. Both cause burning and tanning but UVB was always thought to be the more damaging of the two since it causes more rapid burning of the skin. In fact, until recently when it was discovered that UVA actually penetrates much deeper, health experts thought UVA was harmless.

What they now know is that not only does it penetrates far more deeply, causing damage to the collagen that gives skin it elasticity, than UVB, far from being harmless, the UVA wavelength is more closely associated with malignant melanoma and premature ageing than UVB.

And here’s a worrying irony – those countries which have taken the threat of skin cancers seriously and which have encouraged the population to use strong sun-protection creams over the last 20 years are still reporting increased rates of malignant melanoma. These include the U.S., Canada, Australia, and the Scandinavian countries. The rise is also particularly marked in Queensland, Australia, where sunscreens were first introduced and heavily promoted by doctor.

Scientists are now concerned that sunbathers may have been using high-protection creams that only blocked the UVB rays and that this might explain why, despite and even because of the use of certain suncreams, skin cancer rates have risen.

To sunbathe safely remember that frequent, short exposures are not only safer but more beneficial than a prolonged dose of sunlight. Also, early morning sunshine has been identified as the most beneficial.

Source: Susan Clark 2009

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