The Sunshine of Your Life

A long time ago I wrote a blog post (Here) about how a crippling disease had returned to the UK. This disease (called Rickets), was not caused by some immunity to anti-biotics or some super-strain bacteria. The main cause of Rickets is simply a deficiency of vitamin D.

One of the main sources of vitamin D is sunlight.

It turned out that a number of parents were so paranoid about the possibility that their children might get cancer from the sun they forebade them from playing outside. This coupled with a lousy diet led to their children getting Rickets.

But it now turns out that this deprivation of sun exposure was also likely to statistically shorten their children's lifespan by up to 2 years as well.

It would also have zilch effect on reducing any risk of getting cancer.

This information comes from an authoritative recent Swedish Paper (Article Here and Paper Here)

Previous studies have taken a high, dangerous sun exposure level and then compared that to lower levels of exposure. The lower exposure groups suffered less incidence of cancer. So it became a given among many that sunlight, (any sunlight) was a cancer risk The assumption was made that the less sun you got the safer it was.

This new study of 30,000 Swedish women, conducted over 20 years, was done differently. It started with a group which had little/no sun exposure and then compared their life expectancy (and risk of various diseases) to two other groups within the 30,000 women, One group had moderate sun exposure and one group had higher (though not extreme) sun exposure.

The study found that those that had greater sun exposure lived longer. This was mainly due to a reduction in non cancerous illness such as heart disease.

Even so, when looking across all groups, from those with no sun exposure through to those with high but sensible sun exposure, the rate of cancer deaths was at least unchanged if not slightly reduced for of the sun worshippers.

The effect of sunlight on improving life expectancy is so marked that smokers who sun-bathed had the same life expectancy as non smokers who had no sun.

Notice how is all these graphs those avoiding sun suffered the highest death rate after 20 years.

 As the paper makes clear, it could be that some of the benefits of sun exposure may stem not from the sun but from a better lifestyle reflected in the ability to do more more sun bathing.

But whatever the reasons, the study blows a big hole in the concept of Linear No threshold (LNT) risks associated with sun exposure. Clearly too much sun is dangerous. But then again so is too little.

There is no linear relationship of risk versus sun exposure.

But whatever.

It is good to know that you are actually doing your kids a favour by letting them play in the sun.

As with almost all things in life, the important thing is to act with moderation and common sense.