The Sun�s Health Benefits Go Way Beyond Vitamin D
By John Naish
Guest writer for Wake Up World
We humans desire to soak up some solar rays.
But no, we keep being told: the threat of skin cancer makes this potentially lethal.
Now, however, scientists are discovering the positive side to sun-worshipping: statistically,
getting a good dose of sunshine makes us live longer, healthier and happier lives.
Emerging research indicates that sunlight may protect us against a wide range of lethal
or disabling conditions, such as obesity, heart attacks, strokes, asthma, and multiple
sclerosis.
Sunshine has also been shown to boost our libidos, cognition and general mood.
But this is not simply about vitamin D, which our skin manufactures from sunlight.
While the �sunshine vitamin� helps us build healthy bones and teeth and may protect
against bowel cancer, new research indicates that solar rays also benefit our bodies in
multiple other ways.
Scientists now believe, for example, that exposure to sun prompts our bodies to produce
nitric oxide, a chemical that helps protect our cardiovascular system, and the feel-good
brain chemical, serotonin.
Lack of Sun as Bad as Smoking
A major clue about sunshine�s benefits has emerged from a study of nearly 30,000 Swedish
women whose sunbathing habits have been followed for 20 years.
In March this year, investigators from the world-renowned Karolinska Institute in Stockholm
concluded that avoiding the sun is actually as bad for your health as smoking.
The study, published in the Journal of Internal Medicine, found that 1.5 women in 100 who
reported they had the highest exposure to ultraviolet light (by sunbathing up to once
a day) were found to have died during the two decades, compared with three in 100 for
women who said they had avoided sunbathing.
The avid sunbathers had a significantly lower risk of death from cardiovascular disease
and other conditions that were not related to cancer, the researchers explains.
Dr Pelle Lindqvist, the epidemiologist who led the study, says the research also found
that:
�Non-smokers who avoided the sun had a life expectancy similar to smokers in the highest
sun exposure group, indicating that avoiding the sun is a risk factor for death of a similar
magnitude to smoking.�
Older People Need More Dr Richard Weller, senior lecturer in dermatology
at Edinburgh University, last year published a report in the journal Maturitas warning
that older people in particular need to get into the sun more.
He explains:
�Advice on healthy sun exposure needs to be reconsidered� The older population are
particularly sun-deprived as shown by low blood levels of vitamin D and lack of outdoor
activity.�
He adds that there is a reduction in cardiovascular disease and deaths from all causes with increased
sun exposure, meaning sunlight actually offers a protective effect.
Two years ago, Dr Weller�s team established that exposure to sunlight may lower people�s
blood pressure and thus cut their risk of heart attack and stroke � and this benefit
has nothing to do with vitamin D. Instead, it is due to the fact that when our skin is
exposed to the sun, a compound called nitric oxide is released in our blood vessels which
in turn lowers blood pressure by causing blood vessels to widen.
Dr Weller told Good Health:
�It also appears that sunlight alters the way that our genes behave.
Last year, Cambridge University scientists showed that the expression of 28 per cent
of our entire genetic make-up varies from season to season.�
Sunshine Helps Reduce Inflammation The Cambridge investigators Dr. Weller referred
to reported in the journal Nature Communications that, in winter, our bodies naturally increase
the activity of inflammatory immune-system genes � to combat infectious bugs � and
in summer, increase the activity of anti-inflammatory genes.
Chronic inflammation is linked to modern epidemics such as heart attacks, diabetes and cancer.
Such inflammation results from our immune systems fighting infectious invaders.
But this comes at a cost, as the tissue damage caused by long-term inflammation can itself
cause disease.
However, the Cambridge research indicates that sunlight may prompt our bodies to switch
down the inflammatory response.
Says Dr Weller:
�As well as nitric oxide and gene expression, I think there will be other factors that we
have yet to discover�
There is a correlation between more sun and less disease in a variety of conditions such
as multiple sclerosis and atherosclerosis, where arteries are clogged by fatty substances
known as atheroma.�
However, the causal link is yet to be shown.
Sun Exposure May Help You Avoid Gaining Excess Weight
Scientists are discovering sunlight may even help us keep slim and healthy, according to
studies by the Universities of Southampton and Edinburgh which kept mice on high-fat
diets while they were exposed to the spectrum of ultraviolet light found in sunshine.
The results show that ultraviolet radiation may suppress the development of obesity and
the symptoms of type 2 diabetes.
These benefits were again independent of the effects of vitamin D, the researchers reported
in the journal Diabetes in 2014.
Instead they believe the effects are again the result of sun exposure boosting the production
of nitric oxide.
The suggestion is that, without enough nitric oxide in the bloodstream, insulin may not
work properly, allowing diabetes to set in.
Sun Lowers Risk of Stroke Other research indicates that being exposed
to plentiful sunlight may reduce our risk of stroke.
Epidemiologists have used weather-satellite records to determine how much sunlight more
than 16,000 people living across the U.S. individually experienced over a period of
15 years.
The University of Alabama analysis revealed that the more sunshine someone experienced,
the lower their risk of stroke.
The study, published in the journal Annals of Neurology in 2013, called for further research
into this link.
Sunshine Improves Mood, Decreases Depression
We all tend to feel happier when the sun is out, and this is not simply a matter of morale.
Research shows that the main wavelength of light in sunlight stimulates sensors in our
retina which regulate our body clock.
This in turn regulates the amount of melatonin, the sleep hormone, that our bodies release.
Studies such as a report by Sweden�s Uppsala University last month in the journal PLOS
One, show disruption of melatonin levels is linked to depression, as well as Alzheimer�s
and Parkinson�s disease.
Sunlight also lifts men�s libidos, according to an Austrian study of 2,299 men published
in 2010.
Hormone experts at the University of Gratz discovered that the men�s levels of the
male sex hormone testosterone peak in the month of August (during the northern summer),
and fall in the winter, hitting their lowest levels in March.
Sun Can Help Improve Children�s Eyesight
Lack of sunlight has physical effects on children, too.
A study by the Australian Research Council�s Centre of Excellence in Vision Science in
2009 found those who spend most of their time indoors have a significantly increased incidence
of �high myopia�.
The researchers believe that the neurotransmitter dopamine is responsible.
It is known to inhibit the excessive eyeball growth that causes myopia.
Sunshine also causes the retina to release more dopamine.
May Help You Live Longer Could such physical benefits actually outweigh
the risk of developing skin cancer?
The official NHS guidance clearly says not.
�There is no safe or healthy way to get a tan from sunlight�, it states, adding
that we should try to stay in the shade between 11am and 3pm from March to October, to cover
up with suitable clothing and sunglasses during these times, and to use at least SPF15 sunscreen.
Dr Weller ackowledges that people who live in sunnier climates have more skin cancer,
because excessive solar radiation can mutate DNA and generates free radicals that may cause
cancers to develop.
But, he argues, we have no proof that sunlight shortens life.
�In fact, the epidemiology suggests that overall, people who have more sunlight tend
to live longer, even though their population gets more skin cancer.�
Dr Weller is supported by Martin Feelisch, the professor of experimental medicine at
Southampton University who has also been studying sunshine�s role in keeping us healthy � in
particular the effect of sunlight-stimulated nitric oxide to protect our cardiovascular
systems by lowering blood pressure.
Professor Feelisch warns that avoiding sunlight or constantly using sunblock could be a new
risk factor for heart disease � and more people die from heart disease than skin cancer.
�We believe current public health advice, which is dominated by concerns of skin cancer,
needs to be carefully reassessed� It�s time to look at the balance of risk for skin
cancer and cardiovascular disease.�
Meanwhile, Dr Lindqvist, the author of the new Swedish study, says:
�We know in our population, there are three big lifestyle factors [that endanger health]:
smoking, being overweight, and inactivity.
Now we know there is a fourth � avoiding sun exposure.�
We should also be reconsidering our use of sunscreen, as it may block the benefits of
sunshine, Dr Lindqvist says.
�If you�re using it to be out longer in the sun, you�re using it in the wrong manner.
However, if you are stuck on a boat and have to be out, it�s probably better to have
sunscreen than not to have it.�
Thanks to our new scientific appreciation of sun, the balance does seem to need redressing
towards enjoying it in healthy moderation.
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