Can suncream RAISE your risk of skin cancer?

Think slathering on high-factor lotion will keep you protected? Think again, say these experts . . .

Most of us think we know how best to stay safe in the sun — cover up, stay in the shade at midday and invest in a high-factor sunscreen.

But increasingly research is casting doubts over what we know about sun protection and, in particular, our understanding of sunscreens.

only this month an investigation by the consumer watchdog Which? found that some of the sunscreens marketed as providing ‘once-aday’ protection don’t live up to the promise.

But as these experts reveal, that’s not the only concern. With a flaming June on the cards, we should all take heed of their advice . . .

FACTOR 50 ON A TUBE MAY NOT MEAN FACTOR 50 ON YOUR SKIN

THE SPF — or Sun Protection Factor — is a rating of the time it takes for the skin to burn using that product. For instance, SPF30 means that if your unprotected skin starts burning in three minutes, it would take 30 times longer — 90 minutes — to burn wearing that lotion.

When a sunscreen’s SPF is tested in the laboratory, it’s applied on volunteers in thick layers. But few people in real life apply them as thickly. In fact, we use as little as a quarter of the recommended amount, which essentially gives us four times less protection, suggests a recent study included in a review in the International Journal of Dermatology.

Adults need two tablespoons ( 35ml) of sunscreen per full body application — ‘equivalent to a shot glass’, says Anjali Mahto, a consultant dermatologist and British Skin Foundation spokesperson.

this should be applied three times a day, adds clare o’connor, manager of innovation and research for skin protection at Boots. If you’re using enough sunscreen, a standard 200ml bottle should only last six applications and you would need seven bottles for a two-week holiday, she says.

even applying sunscreen properly is not enough, suggests Anton Alexandroff, a consultant dermatologist at the university Hospitals of Leicester NHS trust.

‘Shade and clothes are more effective than a cream could ever be,’ he says.

Justine Hextall, a consultant dermatologist at Western Sussex Hospitals NHS trust, agrees. As well as using sunscreen, she sits with her back to the sun when outside, and when she and her family are at the beach, they wear UV clothing that protects against the sun’s harmful rays.

SHOULD YOU USE LAST YEAR’S LEFTOVER BOTTLE?

Just like any medicine or cosmetic product, suncream has a shelf life, as the active ingredients’ potency degrades. this is normally two to three years — even if it’s opened, as long as it’s within its use-by date. However, direct sunlight can interfere with the active ingredients inside the bottle and destroy them, rendering the cream ineffective, so keep it in the shade.

A 2013 survey by Asda found that 57 per cent of people use out-of-date sunscreen and that 26 per cent apply cream that is more than two years old, meaning that it provides only a fraction of the intended protection.

STAR RATING THAT MAY NOT STOP YOU BURNING

SUNSCREENS come with protection against UVB rays, the SPF rating, and UVA rays, expressed as a star rating.

UVA rays can penetrate the skin more deeply and are thought to be a major cause of wrinkling, sagging and dryness. UVB rays are what causes sunburn and are thought to be what drives the development of skin cancer.

A five-star rating means a product’s UVA protection is just as good as the protection it provides against UVB. It’s worked out using a ratio. So a low SPF cream can still have a high star rating for UVA, not because it is providing lots of UVA protection, but because the ratio between the UVA and UVB protection is roughly the same.

WHY YOU CAN’T ALWAYS TRUST SPF GUIDES

Most people believe a high SPF guarantees high protection. to a certain extent that’s true — an SPF50 sunscreen should protect against 98 per cent of UVB rays, compared with SPF30, which blocks 96.7 per cent. While higher SPFs do block marginally more sunlight, the key is that SPF rating relates to timing and how long it takes to burn.

Yet not all live up to the label. Last week, the u.S. watchdog consumer reports published results on tests it conducted on 65 sunscreens, including many available in the UK; 43 per cent of those with an SPF30 or more didn’t meet that level.

Similarly, last year the Australian consumer group choice found that four of the six SPF50+ sunscreens it tested failed to deliver the claimed UV protection.

to determine a product’s SPF, it is tested in thick patches on the skin of volunteers, who are then exposed to artificial sunlight. But using just one test, as the u.S. consumer reports did, is unreliable, argues clare o’connor. ‘Manufacturers don’t use a single test, so I would go with what the manufacturers claim rather than what this report found.’

Another potential issue is the effect certain ingredients have on SPF.

In 2012, a team from the university of nantes in France found that certain ingredients added for their antiinflammatory effects to reduce redness could skew SPF readings, reported the journal Plos one.

this is because the chemicals delay the rate at which the skin turns red under UV light, so the sunscreen gets a higher SPF score than merited.

SUNSCREEN MAY NOT PREVENT SKIN CANCER

The general consensus is that sunscreens will help prevent skin cancer. But no studies so far have actually proven this link outright.

While we know sunscreens stop our skin burning, there is not enough evidence to clearly show their use actually protects against or prevents skin cancer, says Dr Alexandroff, ‘although logically, we assume that it does’.

What this means is that we shouldn’t rely on sunscreens — they are secondary prevention. Dermatologists writing in the journal clinical Pharmacology & therapeutics in 2011 argued that primarily we should be simply avoiding the sun and exposure to UV light.

More recently, a study by Manchester university published in the journal nature in 2014, showed that sunscreen cannot be relied on alone to prevent malignant melanoma, the most deadly form of skin cancer. even SPF50 sunscreen allowed enough UV radiation through to damage the DNA.

IT CAN GIVE A FALSE SENSE OF SECURITY

SOME researchers go so far as to suggest sunscreen could be indirectly contributing to the risk of skin cancer. This is because people assume it provides all the protection they need, so they spend longer in the sun and end up with high doses of UV radiation, says Dr Alexandroff.

Writing in the British Journal of Dermatology in 2009, researchers from the International Agency for Research on Cancer in Lyon, France, argued that ‘individuals should be advised not to use sunscreen, but rather to . . . set strict limits on the time they spend in the sun’.

They also suggested that product labels should inform consumers of the ‘carcinogenic risks associated with sunscreen abuse’ — much like packets of cigarettes warn of their risks of smoking.

Another issue, argue some experts, is that chemical sunscreens reduce redness and burning, creating a false sense of security.

This makes people think they’re OK to remain in the sun, when actually UV rays still get through and cause DNA damage without there having been burning, says Mark Birch-Machin, a professor of molecular dermatology at Newcastle University, who is researching ways to improve sunscreens.

Question marks have also been raised about certain ingredients potentially raising the cancer risk.

Studies have shown that when retinyl palmitate, a form of vitamin A often added for skin health, is exposed to UV radiation, harmful particles known as free radicals are formed.

Free radicals can interact with DNA and potentially cause cell mutations leading to cancer. However, the research has been mixed. Furthermore, sunscreen formulations that include this chemical also contain antioxidants such as vitamin C and vitamin E, which mop up free radicals.

Lab studies suggest that oxybenzone, an ingredient found in nearly every chemical sunscreen, also produces free radicals when exposed to UV.

But, in general, the risk of that is outweighed by the protection the chemical provides to the skin, says Dr Hextall.

IT COULD DAMAGE MEN’S FERTILITY

SUNSCREENS are classed as a cosmetic product rather than medicinal, so the standards they must meet before they can go on the market are much lower, says Dr Alexandroff.

He adds that we don’t know about their potential ill effects, if any. But some early research suggests some cause for concern.

There are two types of ingredients in sunscreens — physical blocks and chemical blocks.

Physical filters sit on the surface of the skin and deflect rays, whereas chemical filters, such as oxybenzone, penetrate the skin’s top layer and absorb UV rays. Some sunscreens contain both chemical and physical UV blocks.

It has now been suggested that chemicals commonly used in sunscreens may interfere with the function of sperm cells — potentially by mimicking the effect of the female hormone progesterone — according to a study presented at a recent Endocrine Society conference in Boston.

In a lab study, Danish researchers tested UV filters used in sunscreens on healthy human sperm cells. Almost half caused an increase in calcium in the cells, interfering with their normal function.

‘This effect began at very low doses of the chemicals,’ they said. ‘Our study suggests that regulatory agencies should have a closer look at the effects of UV filters on fertility before approval.’

However, fertility experts are still to be convinced. The lab study exposed sperm to sunscreens, which is very different from what happens in reality, says Allan Pacey, a professor of andrology from the University of Sheffield.

‘We don’t actually know whether when you apply it to your skin, any of the sunscreen chemicals even reach the testicles,’ he says.

‘Until there is evidence that suggests men who use lots of sunscreens are less fertile, men should continue to use it as normal.’

WHY PRICE MAY NOT MATTER

THERE is a huge variety of products, with different formulations for faces, say, or younger skin — but an SPF50 product with a four/ five star UVA rating will be more than adequate for your entire family’s face and body, says Clare O’Connor.

‘In terms of protection and active ingredients, it would be the same,

regardless of its formulation,’ she explains. You don’t even really need special sunscreen for your face, adds Dr Mahto.

The skin of the face and different parts of the body may have different needs, but essentially the active ingredients in sunscreens are the same and it is possible, if needed, to use the same product on the face and body, she says.

Sometimes more expensive products will contain certain plant extracts or minerals shown to protect skin cells from UV damage, but in practice the dose is too low to be effective, says Dr hextall.

People with sensitive skin or children tend to tolerate physical sunscreens (which tend to come out white, and contain either zinc oxide or titanium dioxide that sit on the skin) slightly better than chemical ones, as these are less likely to cause skin reactions such as dermatitis, says Dr Mahto.

For her family, Dr hextall uses an SPF50 sunscreen with chemical and physical filters, and antioxidants to mitigate against free radical damage. She also adds a zinc oxide stick for vulnerable areas around the eyes, ears and nose.

THE ‘NEW’ SUNRAYS THAT COULD DAMAGE SKIN

CONVENTIONAL sunscreens block out UV rays, but research is now pointing towards a new harmful sunray — infrared, which are the rays that we feel as heat.

One type in particular, infrared a, can penetrate the deepest layers of the skin, deeper than UV.

Recent lab research suggests that infrared (combined with UVB) may play a role in skin cancer. But we don’t know how to block infrared, says Professor Birch-Machin, adding that the role of infrared rays in skin cancer is highly controversial.

clare O’connor says Boots is working with researchers to see if infrared is a real risk, or just a gimmick; how much exposure we get to it in real life is unclear, she adds.

GO UNPROTECTED FOR 15 MINUTES A DAY

FOR many, one of the arguments against using sunscreen is that we may not get enough vitamin D — an SPF30 product, for instance, reduces the skin’s capacity to produce vitamin D by almost 98 per cent.

But Dr hextall says: ‘You don’t need a lot of sun exposure to make the amount of vitamin D your body needs every day.’

Don’t avoid sunscreen completely, she adds, but do go outside unprotected for 15 minutes between 11am and 3pm, when the sun is at its strongest.

australian scientists have recently developed a sunscreen they say allows the body to produce vitamin D while still blocking harmful rays.

Solar D contains compounds that filter light differently — in a laboratory study, it led to almost 50 per cent more vitamin D compared with a standard SPF15 cream, reports the journal PLOS One.