The Debate: Sunscreen, good or bad?

Conventional Wisdom has us in fear of the Sun.

For thousands of years, the Sun has been revered, even worshipped as a deity for its life giving properties, but now the official line is that the Sun is to be feared. You should stay out of the Sun, or at least cover yourself in sun cream, for fear of getting burned, or even worse getting skin cancer.

The question is, is this fear justified?

Check out this head to head debate in the BMJ on “Is Sun Exposure a Major Cause of Melanoma?”

Dr Sam Shuster argues NO.

I strongly recommend you read the full text, but in summary Dr Shuster argues that:

• 75% of melanomas occur on relatively unexposed areas of the body
• Relationship to latitude is small and inconsistent
• Incidence and Mortality FALL WITH GREATER EXPOSURE
• Incidence is unaffected or INCREASED with the use of sunscreens
• The effect of sunbeds exposure is small and inconsistent

Dr Scott Menzies, however argues YES sun exposure can cause melanoma.

Again I would recommend that you read the full text, but here are a couple of the main points:

• Incidences of melanoma are higher in people with lighter skin that has a tendency to burn
• Some studies have shown an association between sub burn and melanoma risk

It must be remembered however, that association does not prove cause and effect. There could easily be confounding factors.

Take for example this story in the Daily Mail in which a 21 year old girl died from skin cancer, despite avoiding sun exposure and sun burn.

Had she been a tanning addict, Doctors would have been quick to pin the blame on the sun. Instead, this case is described as a mystery, but we are all advised to protect ourselves from the sun anyway, regardless of the fact it was of no help to her.

So is the risk of skin cancer from too much sun a complete myth then?

Unfortunately its not quite that simple. There may be no definitive link between sunburn and melanoma, but there does seem to be a correlation between sun exposure and risk. Dr Menzies also identifies that:

• As latitude decreases, risk of melanoma increases in white Europeans

Unfortunately, this is more epidemiological data, which is notoriously fraught with confounding factors.

Case-Controlled studies are generally much more accurate, and Dr Menzies cites interesting evidence from two meta-studies:

• Chronic sun exposure (consistent) is NEGATIVELY associated with melanoma risk
• Intermittent exposure and sunburn is positively associated with melanoma
• Use of sunscreens does not reduce risk of melanoma

So what conclusions can we draw from these two opposing arguments?

1. Sunscreen use is not backed by good evidence. Not only may it not protect you from melanoma, its use may also increase risk of skin and other cancers
2. Getting sun burnt is also very unwise. Although the evidence that sun burn causes melanoma is not conclusive, sun burn has been linked to carcinomas, another type of skin cancer that is not usually life threatening, but can cause serious suffering and scaring. Pain is your body’s way of telling you something is wrong, and should be avoided.

It seems that a “healthy tan” is just that. Consistent sun exposure is necessary for vitamin D production, a deficiency in which has been show to increase risk of:

• Osteoporosis
• 16 Types of Cancer
• Cardiovascular disease
• Diabetes
• Hypertension
• Multiple Sclerosis
• Hypertension
• Psoriasis
• Rickets
• Schizophrenia
• Myopathy
• Tuberculosis

Is it possible that the association between sunburn and melanoma risk is actually due to the fact that people that get sunburnt do so because they get very infrequent exposure to the sun?

Perhaps white Europeans that live nearer to the equator get less unprotected sun exposure than those in more temperate areas as they are too scared to bare their skin to the hot sun due to all the melanoma scaremongering?

Although we might not know the exact cause of melanoma, we do have enough information to put together some guidelines for getting some sun.

• Get some sun exposure everyday
• Do not use sunscreens
• Do not get burnt

Depending on your skin tone, and your location, the amount of time you can spend out in the sun is going to vary tremendously.

If you are very pale and the sun is very hot, start out with just 10 mins per day, avoiding the midday sun.

After 10 mins, or sooner if you start to feel prickly heat or uncomfortable, cover up with clothing and/or move into the shade.

As you start to build up a tan you can gradually increase your daily sun exposure.

More is not necessarily better, however. Get enough to maintain a healthy tan, and no more. Cooking yourself all day everyday until you have skin like leather is very unlikely to be a wide idea!

If you have dark skin and live in a cooler climate you have to be very careful of vitamin D deficiency, particularly in the winter. In fact, with 9-5 jobs, cars and winter clothing, (plus fear of the sun when it does show its face), this applies to everyone.

Try and get some sun exposure each day even if its cold – Remember it doesn’t count if you’re wrapped up from head to foot. If you really can’t get out there, take a vitamin D supplement to keep you topped up till summer.

Hopefully though, there’ll be no need for any vitmain D supplementation for a while, and we can all get a great health boost over the upcoming bank holiday bonanza!