SUNCREAM’s Hazardous Chemical Cocktail
It is not inevitable that sun exposure will lead to photo-ageing (dry, wrinkled skin), or even to skin cancer. Nevertheless, the sun is now officially the enemy - against which sun creams are our weapons of choice.
Chemicals that provide sun protection are also potentially irritating to the skin, and irritated skin is more prone to sun damage. Emerging research also suggests that some of these chemicals are oestrogen mimics that persist in the environment and in the body. Potentially, this could lead to gender-bending effects in men and boys, and breast and ovarian cancer and reproductive abnormalities in women.
Sun Myths
Used properly, sun screens will prevent sunburn, but evidence of protection against most skin cancers is inconclusive. Sun screens may reduce the risk of squamous cell carcinoma, but their effect on the more serious basal cell carcinoma and the more deadly malignant melanoma is uncertain. Indeed, some studies have linked regular sun screen use to higher rates of melanoma among men and basal cell carcinoma among women.
In contrast, most of the body's vitamin D supply - between 75 and 90 per cent - is generated by the skin's exposure to UVB rays. Using a sun screen drastically lowers the cutaneous production of vitamin D. Combined with sedentary indoor lives, this raises the risk of vitamin-D deficiency disorders such as rickets, osteomalacia and osteoporosis. It may also increase the risk of certain cancers.
In the US the number of deaths from skin cancer is believed to be in the region of 10,000 per year. Premature deaths from cancers (breast, prostate and colon) associated with inadequate sun exposure are estimated at two to three times that figure.
Protection money
Last year the UK sun-care market generated £182m. In particular, government advice for us all to cover up has boosted the sales of higher protection factor creams. SPF 15 and SPF 25 are now the UK's most popular choices. Unfortunately the higher the SPF the more chemicals the cream will contain.
The leading brand in the UK is Boots' Soltan, which claims around 19 per cent of the market. Ambre Solaire and Nivea come next, followed by Piz Buin and Tesco's own brand.
Safe sun
The SPF number defines how long you can stay in the sun before getting burnt. If you normally turn pink after 20 minutes, an SPF 15 product will extend this period by 15 times (ie five hours). The SPF applies only to protection from UVB radiation, not the more harmful UVA radiation.
Sunburn is easily preventable by staying out of the sun between 11am and 2pm. It can also be prevented by wearing appropriate clothing. The average T-shirt has an SPF of seven, and 85 per cent of fabrics tested in an Australian study had and SPF of 20 or more.
A safe sun screen?
Isotridecyl salicylate,
Health effects:
Butyl methoxydibenzoylmethane
Octocrylene
Glycerin
Potassium Hydroxide
Butane, Isobutane and Propane
Parfum
Ingredients with unknown health effects:
C12-15 alkyl benzoate
Diethylhexyl butamido triazone
Polyglyceryl-3 methylglucose distearate
C18-36 acid glycol ester
PVP/ hexadecene copolymer, acrylates/ vinyl isodecanoate crosspolymer
Dipropylene glycol
Xanthan Gum
Dimethicone
Parfum
Purpose:
Methylparaben, butylparaben, ethylparaben, isobutylparaben, propylparaben, butylated hydroxytoulene, tetrasodium EDTA, phenoxyethanol
The problem is that using sun creams on their own to prevent skin damage is like trying to lose weight by ordering a diet Coke with your Big Mac and fries. Because sun creams encourage a false sense of security, we stay out in the sun far longer than is smart or safe. Few of us apply sun creams as regularly or as thickly as manufacturers recommend. In real-world terms, this means that the sun protection factor (SPF, see below) listed on the bottle is always misleading.
While it is impossible to make an effective sun cream without chemical sun screens or mineral sun blocks, it is possible to make a sun cream that is low in skin irritants and is without synthetic perfumes or petroleum-derived polymers (plastic-like substances that 'glue' the sun screen to your skin). Products that use mineral sun blocks, such as titanium or zinc oxide, tend to be less irritating than chemical sun screens.
Pat Thomas is the author of several books on environment and health issues, including: Cleaning Yourself to Death: how safe is your home?, Living Dangerously: are everyday toxins making you sick? (both published by Newleaf) and Under the Weather: how weather and climate affect our health (Fusion Press)
Octyl salicylate
Purpose:
UVB filter and antiseptic
Skin irritants; some salicylates have hormone-disrupting potential.
Purpose:
Health effects:
Purpose:
Purpose:
Health effects:
Purpose:
Health effects:
Purpose:
Health effects:
Purpose: Synthetic moisturiser and preservative
Purpose: UV filter
Purpose: Emulsifier - holds the mixture of water and oils together
Purpose: Synthetic moisturiser
Purpose: Keep the product stuck to the skin and improve water-resistance
Purpose: Solvent
Purpose: Thickener, stabiliser
Health effects:
Purpose:
Health effects:
Excessive worries about skin cancer and increasingly sedentary, indoor lifestyles mean that many otherwise healthy, adequately nourished individuals are not getting enough sunlight. Because 75-90 per cent of the body’s supply of vitamin D is synthesised in the skin as a result of sun exposure (Prev Med, 1990;19:614-22), this means they are also not getting enough vitamin D.
The problem is especially acute in northern latitudes where sunlight is at a premium anyway; in the UK, for example, there is not enough sunlight between October and March to generate any vitamin D synthesis in the skin. But even in sunny Australia many individuals may have insufficient sun exposure to allow adequate synthesis of vitamin D in the skin (Med J Aust, 2001;175:236-7). In addition, if you always use a sunscreen when you go out you are reducing the production of vitamin D in your skin (J Natl Cancer Inst, 1994;86:78-9); sunscreens block between 80 and 100 per cent of vitamin D synthesis.
When the sun is out we need to be much more opportunistic about exposure, allowing ourselves at least 15-20 minutes unprotected exposure three or more times a week on around a quarter of your total skin surface area (the kind of exposure one might get wearing a T-shirt and shorts). Dark-skinned people take up to six times as long to make the same amount of vitamin D as white-skinned people. So in the UK a person with dark skin would ideally need to sunbathe for three two-hour sessions per week to achieve an optimum amount of vitamin D. It is impossible in practice for most people in the UK to achieve this length of time in the sun.
Without adequate sunlight exposure there is a well-known risk of vitamin D deficiency disorders such as rickets, osteomalacia and osteoporosis. But voluminous evidence suggests that vitamin D and sunlight may also be important to human health in ways that are unrelated to their effects on bone, including immune and central nervous system disorders and cancer (see articles in ICM Journal, Sept and Oct, ’03 by Simon Best, The UV Advantage by vitamin D world expert, Prof Michael Holick (reviewed July, 2004), The Healing Sun by Dr Richard Hobday (reviewed Sept, 2003), and Sunshine Robbery by ex-Sunday Times medical correspondent Oliver Gillie (published in 2004 by the Health Research Forum; see www.healthresearchforum.org.uk).
The reason for these widespread, positive effects is that vitamin D acts more like a steroid hormone than a vitamin. It has now been found that at least 30 organs and tissues have vitamin D receptors and require adequate amounts of vitamin D to function optimally (Zittermann A. Br J Nutr 2003;89(5):552-72). The evidence is now such that in March both Australian and UK authorities were forced to change their guidance on vitamin D and sun exposure due to the rising incidence of vitamin D deficiency observed in Australia (News, April, ’05).
Such a dramatic U-turn needs to be strongly and systematically communicated to the general population so that they can re-assess their sunbathing habits and use of suncream to the benefit of their overall health.
|
Return to CONTENTS Page
| Your use of this site is subject to Terms and Conditions of Use |
See also our Privacy Policy |