How good are sun lotions?
Bupa investigative news - Updated 23 March 2004. First published: 6 October 2003
written by Rachel Newcombe, reporter for Bupa's Health Information Team
In the UK there are 65,000 cases of skin cancer each year, with 2,000 proving fatal, and numbers are said to be rising faster than for any other form of cancer. Part of the reason is thought to be due to our changing lifestyles, for example more people are sunbathing and taking more holidays in sunnier climates, increasing their exposure to harmful UV rays.
Part of the Government's safe sun message advises people to use protective sunscreen but, according to new research, while useful for protecting against UVB rays, lotions are less protective against harmful UVA. What's more, it's possible that people might be staying out in the sun longer because they think their skin is being protected, actually increasing their exposure to UVA.
The danger from UVA rays has been given further backing by Australian research that was published in March 2004. In this study, Australian researchers found that UVA rays caused DNA damage to the cells deep within the skin. It is this layer of cells that regenerates our skin and it is feared that damage to the DNA of these cells may increase a person's risk of developing skin cancer.
So what do these findings mean for people wanting to sunbathe and use sunscreens?
KEY POINTS
Sunlight contains UVA and UVB.
Exposure to UVB increases the risk of basal cell carcinoma and squamous cell carcinoma, two forms of non-melanoma skin cancer. It is also responsible for sunburn.
Exposure to UVA causes skin ageing and there's a high level of concern that UVA increases the risk of malignant melanoma, the most dangerous form of skin cancer. In contrast to UVB, UVA does not cause sunburn.
Sunscreen sun protection factors (SPF) are measured by timing how long skin covered with sunscreen takes to burn compared to uncovered skin. For example, SPF 15 means it will take 15 times longer to burn when wearing the sunscreen.
Because SPF factors only look at burning times, they only apply to UVB rays.
A study carried out by scientists at Restoration of Appearance and Function Trust (RAFT) looked at three high-factor sunscreens and their ability to protect against UVA rays.
Although they found that the lotions did protect well against UVB rays, the UVA protection was less than satisfactory.
Despite the findings, RAFT and other experts still stress the need to use sunscreen, but warn people not to rely solely on it.
Good sun protection methods include staying in the shade during the peak sun strength times, covering up, wearing sunglasses and a wide brimmed hat and using an SPF 15 or higher sunscreen.
It's hoped that future sunscreens will include better protection against UVA.
What were the headlines?
The sunscreen research in October 2003 was picked up by the majority of UK newspapers and websites, gaining front page coverage on some of them. The headlines included, "Cancer warning over sun creams", "Sun lotion 'raises risk of cancer'", "Sunscreens fail to offer full protection", "Sun cream cancer alert", and "Sun lotions 'are not effective'".
What is the bigger picture?
The October 2003 research was carried out by scientists, led by Professor Roy Sanders, at the Restoration of Appearance and Function Trust (RAFT) at Mount Vernon Hospital in Northwood, Middlesex, and details were published in the October issue of the Journal of Investigative Dermatology.
Tests were carried out with three leading brands of high sun protection factor (SPF) sunscreen, all of which claim to protect against UVA. A technique called electron spin resonance (ESR) was used to detect free radicals in human skin - a sign of UVA penetration and skin damage. Patients undergoing surgery, for example for breast reductions, agreed to donate samples of skin and the sunscreens were applied to the skin in the recommended doses - 2mg/cm2.
Dr. Rachel Heywood, a principal scientist at RAFT, explained the process to Bupa. "We exposed skin to a UVA light source and we were able to detect free radicals which are produced in response to UVA light. We measured how much high-factor sunscreens, all offering UVA protection, were actually protecting against this free radical production."
They discovered that the UVA protection offered by leading sunscreen brands was not what might be expected. Furthermore, even when sunscreens were applied in the recommended concentration, they afforded much lower protection against the melanoma-inducing and skin-ageing UVA light than against UVB.
"We were expecting that it [UVA protection] would be lower than the UVB protection," said Dr. Heywood, "but we were surprised by how much lower it was."
The scientists are concerned that people may use sunscreens to stay out in the sun longer and, although they're well protected against UVB, may not be getting the protection they need against UVA.
As a result of their findings, the researchers conclude, "Since the use of sunscreen creams encourage people to stay longer in the sun and the protection offered by these creams against UVB far outweighs that against UVA - the use of sunscreen creams may therefore indirectly increase the risk of developing the skin malignancy melanoma, rather than protect against it."
"This new research on sun lotions is interesting, but it does not fundamentally change advice for people in the sun.
"It's important to realise that tanned skin is a sign of sun-damaged skin, not healthy skin. Also, in the long term, sun exposure is known to increase the risk of skin cancer.
"The best way to protect skin is a combination of staying in the shade when the sun is at its strongest, using clothing to cover up and high-SPF sun lotions. Sun lotions shouldn't be used in isolation or as a way of staying in the sun for longer."
Dr. Annabel Bentley,
assistant medical director,
Bupa Group
What does this mean?
Commenting on the October 2003 findings, Dr. Mark Birch-Machin, a skin cancer expert at Cancer Research UK, said, "This study highlights the fact that no sunscreen can offer total protection against UV and you should not rely exclusively on it for protection from the sun's harmful ultra-violet rays. Sunscreen should be used as the last line of defence against the sun, but is still an important component of being SunSmart."
A spokesperson for the Department of Health, who run a Sunsafe campaign, said that although sunscreen is important, it won't block all UV rays, so should be used in conjunction with other practical methods, such as wearing a hat, T-shirt or sunglasses and staying in the shade during the peak sun strength time.
They also warned that it's very possible that, "people who spend more time in the sun because they're wearing sunscreen, without taking other precautions, could result in increasing their risk of skin cancer".
Sunscreen manufacturers have insisted their products are safe, but point out that people need to use them sensibly and not depend solely on sunscreens to protect them from the damaging effects of the sun.
Although some of the October 2003 coverage has reported the study in a negative light, dismissing the value of sunscreens, RAFT see it as a positive move and hope that better UVA sunscreens will be developed as a result. "We believe the UVA should match the UVB protection, so that people can make a safe assessment about the protection against damage caused by both UVA and UVB. We're hoping to work with sunscreen manufacturers to achieve that," said Dr. Heywood.
She added that, "The emphasis is on improved protection, rather than completely abandoning sunscreen - we're not recommending that. It's more about sensible sunscreen use with the awareness that it doesn't provide complete protection against the UVA effects at the moment."
ACTION POINTS
To stay safe in the sun:
- Stay in the shade between 11am and 3pm
- Don't rely on sunscreen alone
- Wear clothes that cover your arms and legs, and a wide-brimmed hat
- Wear sunglasses that block UV light to protect your eyes
- If on the beach, wear sun-protective clothing, including swimsuits and wetsuits
- Remember to take extra care with children's skin
- Apply sunscreen with an SPF of 15 or more
- Never burn, as sunburn causes permanent damage
What does this mean to me?
Although the sunscreens tested offered little protection against UVA, experts aren't advocating giving up on sunscreen altogether, as it does protect against UVB. Instead, the consensus is that sunscreen should still be used to complement other sun safety measures.
As Dr. Mark Birch-Machin explained, "As Cancer Research UK's SunSmart campaign advises, people should stay out of the sun particularly around the middle of the day, cover up with clothes and a brimmed hat, seek shade and apply sunscreen factor 15 or higher in generous amounts."
The Department of Health stands by its existing Sunsafe advice, recommending that people use a broad spectrum sunscreen - SPF 15 or higher - in conjunction with other methods.
Dr. Heywood also emphasised that sunscreens should still be used and can be beneficial for UVB. "Sunscreens do protect against burning, which is caused by UVB, and they can protect against the cancers caused by UVB - basal and squamous cancers," she explained.
"The UVB protection is now very good, but we're finding that the UVA protection is much lower and it's because of this that we're concerned," she added.
It's also worth noting, say RAFT, that the sun protection factors (SPF) on sunscreens are only applicable to UVB - there's no recognised standard rating available for the assessment of UVA filters at the moment.
Summary
Although benefits of UVA protection may seem limited in current sunscreens, the lotions are still useful for protecting against UVB rays and should continue to be used. The power of the sun can seem hard to avoid in the heat of the summer, but by following safe sun practices and taking care to protect vulnerable skin, the risk of developing skin cancer can be minimised.
Links for more information
- Bupa skin cancer factsheet
- Bupa be safe in the sun area
- Journal of Investigative Dermatology
- Restoration of Appearance and Function Trust (RAFT)
- Cancer Research UK SunSmart information
