The sunscreen industry would have you believe that all sun exposure is potentially dangerous.
Simon Best argues that other factors like a Western diet may be more responsible for skin cancer.
If there's one thing that everyone looks forward to, it's the summer, and holidays basking in the sun on a beach. But if the ongoing propaganda from official and commercial sources is to be believed, exposing ourselves to the sun is the last thing we should be doing.
Throughout history, the sun has generally been considered a powerful source of beneficial energy, both in myth and reality. In medicine, the practice of heliotherapy exposing patients to controlled amounts of sunlight to cure or alleviate illness was an accepted practice in many countries from the late 19th to the mid 20th century.
Dr Auguste Rollier, probably the most famous heliotherapist of his day, had 36 clinics with over 1000 beds in Leysin, Switzerland. He used sunlight to treat illnesses such as tuberculosis, rickets, smallpox, lupus vulgaris (tuberculosis of the skin) and wounds. Rollier found that sunbathing early in the morning and eating a nutritious diet produced the best results.
However, with the ascendency of the pharmaceutical industry, heliotherapy fell into disuse.
Since the 1960s, the public has been increasingly bombarded with warnings about sunbathing and the risks of skin cancer, with little information on the benefits of sunlight. But reasonable assessments comparing the risks and benefits of exposure to the sun show that the positive effects of sun exposure vastly outweigh its potential hazards.
The incidence of skin cancers has increased over the past few decades (see box on p 2). It is also known that overexposure to solar radiation can cause premature ageing of the skin. However, the vast majority of non melanoma skin cancers are curable and associated with a very small number of deaths (see box on p 2), given a total population of perhaps 40 million sunbathers.
To put the risks from solar radiation into proper perspective, alternative causes of skin cancer and contributory risk factors need to be considered. But first, the actual health risks of UV, the main alleged threat from sunshine, need to be assessed.
UV light can be divided into three main types, according to wavelength (see box on p 1). Of the sunlight reaching the earth, a mere 3 per cent is UV. Both UVA and B promote tanning and sunburn, but UVB is critical for photosynthesis of vitamin D, which is essential for healthy bone development and other processes.
Another argument against the idea that simple exposure to UV radiation causes cancer is the finding that melanomas seldom occur in outdoor workers. A study of US Navy personnel from 1974 to 1984 found a higher risk in sailors with indoor jobs than in those working outdoors (Arch Environ Health, 1990; 45: 261-7). Those working both indoors and outside had the most protection, with a melanoma incidence 24 per cent below the US national average.
Such findings support those of other studies indicating that, while severe sunburn may trigger melanoma, moderate sun exposure may prevent it (Lancet, 1982; ii: 290-3). Indeed, there is some evidence that regular, moderate sun exposure has other benefits as well.
In London based Dr Damien Downing's book Day Light Robbery (Arrow Books, 1981), he states that melanin protects against sun induced free radical damage. He also says: "It seems that even without UV light, skin lipids will take up some oxygen from the air and use it to kill bacteria. However, this effect is much more intense under UV."
The fact that melanomas can occur on the palms and soles of the feet indicate that UV radiation is only one of a number of possible causes and not even the most significant. The incidence of melanoma has been rising in fair skinned populations worldwide, with no corres ponding rise among dark skinned people, who have only one tenth to one third the incidence. Although the much increased melanin in dark skin does provide protection, these populations also tend to spend much more time outdoors in much higher levels of UV light.
For all the other health implications of a thinning ozone layer, there is no hard evidence that ozone depletion, seen particularly at the poles, has caused any increase in melanoma type skin cancer (Br J Cancer, 1992; 65: 916-21).
Melanoma: other causes
One of the main causes of melanoma may be ordinary fluorescent lights. In 1982, British researcher Dr Valerie Beral published a study showing that women who worked under fluorescent lighting had twice the risk for melanoma than those not regularly exposed to such lights (Lancet, 1982; ii: 290-3). Individuals exposed to these lights for more than 20 years showed an increased risk, but the risk was reduced in those who were regularly exposed to sunlight either as children playing outdoors or as sunbathing adults.
In a smaller study of men, the risk of melanoma for those who had over 10 years' exposure to fluorescent lights was over four times higher, rising to a sevenfold risk in those who had spent the least amount of time in the sun as children.
An earlier study by Dr Beral showed that fluorescent lights caused malignant transformation in mouse embryo cells (Science, 1980; 207: 1209-11). A later Russian study (Vopr Onkol, 1987; 33: 35- 9) showed similar results.
Fluorescent lights have been implicated on other grounds. German Professor Fritz Hollwich found significantly higher levels of the stress hormones cortisol and ACTH in those working under ordinary compared with full spectrum fluorescent lighting. This led to the German government's ban on the use of such lights in hospitals and other medical facilities (Ophthalmologica, 1980; 180: 188-97).
The pioneering American photobiologist Dr John Ott has also reported that, when fluorescent lighting was replaced by full spectrum lighting in classrooms, children's previous misbehaviour and hyperactivity were much improved. Similarly, a study by M. Painter found a 32 per cent drop in hyperactivity in children when fluorescent lights were removed from the classroom (Except Child, 1981; 47: 352).
Dr Ott also reports that the number of cavities in children fell by two thirds on switching to full spectrum fluorescent lighting. Research at the University of Alberta, Canada, corroborate these findings (New Sci, 1991; 6 April: 13). Others have found that the more sunlight children are exposed to, the fewer cavities they develop (Am J Public Health, 1939; 29: 777; J Nutr, 1938; 15: 547).
Consumption of margarine and other non butter spreads has been linked to an increase in skin cancer. Essential fatty acid deficient animals were found to be more sensitive to UV, with mild doses producing complete necrosis of the irradiated skin (BMJ, 1957; 14 Dec: 1424-5). Sydney University researchers showed that promotion of UV induced tumours in mice were linked to dietary polyunsaturated fat (Environ Dermatol, 1996; 3 [Suppl 1]: 20-5). Test animals fed 20 per cent saturated fat were almost completely protected from UV tumorigenesis (Photochem Photobiol, 1996; 62: 964-9).
In their book The Perils of Progress (London: Zed Books, 1999), Australian professors John Ashton and Ron Laura, in reviewing the evidence, came to one inescapable conclusion: ". . .saturated fats protect against skin cancer whereas the unnatural increase in refined poly unsaturated fats in the diet from margarines and chemically extracted polyunsaturated cooking oils has actually increased the risk of skin cancer."
Drinking and swimming in chlorinated water can also cause melanoma (J Invest Dermatol, 1980; 75: 122-7; Epidemiology, 1992; 3: 263-5), and sodium hypochlorite, used in swimming pools, is mutagenic (Environ Cell Perspect, 1996; 69: 221-5; Mutat Res, 1988; 196: 211-45). Dutch scientists have linked the worldwide pollution of rivers and chlorination of water to an increase in melanoma (Epidemiology, 1992; 3: 263-5).
Even the Pill has been associated with an increase in melanoma. Beral and colleagues found that, by 1981, the overall incidence of melanoma among Pill takers had increased threefold over non Pill users (US NIH report, 1986; 3: 247-52).
Skin cancer has also been linked with mobile phones and other cell telecommunications. A recent German study found a threefold incidence of uveal melanoma in those using walkie talkies and mobile phones at work (Epidemiol ogy, 2001; 12: 7-12).
The problem with sunglasses
Medicine has also promoted the idea that exposing your eyes to the sun is bad for you. The main argument has been that UV causes cataracts, prompting most people to wear sunglasses that block UVA and B on virtually any sunny day. In fact, the eye may require exposure to the full spectrum of sunlight to stimulate the pathways and organs in the brain that maintain the immune system and other functions.
In Health and Light (Columbus, Ohio: Ariel Press, 1973), Dr Ott argues that sunglasses significantly affect the eyes' natural accommodation reflex and interfere with vital biological interactions.
At the Wills Eye Hospital in Philadelphia, Ott studied the pigment epithelial cells in a rabbit's eye through coloured filters and observed that the colour affected the cell responses. Crucially, he found that the cells only divided in the presence of low level UV radiation.
On the basis of this and other work, he strongly recommends wearing a hat, rather than sunglasses, on a sunny day, except in conditions of high glare (water, snow or desert). American optometrist Dr Jacob Liberman, in his book Light: Medicine of the Future (Santa Fe, New Mexico: Bear & Co, 1991), endorses this view and suggests that our indoor life style ". . .coupled with our excessive use of sunglasses, may be blocking out the UV radiation necessary for normal cell division, thus resulting in certain degenerative eye diseases, such as macular degeneration".
According to Liberman, it was a study in the American Journal of Ophthalmology in 1982 by W.T. Ham and colleagues that led a generation of eye specialists to conclude that any UV is harmful to the eye.
Ham and coworkers tied down monkeys with their eyelids pried open with clamps, then exposed their fully dilated pupils to beams from a 2500 watt xenon lamp for 16 minutes. The intense light contained high levels of UV which, not surprisingly, caused retinal damage. But, as Liberman says, such abnormal exposure would never happen in real life since the eyelids of animals and humans would reflexively close to protect the eyes.
There is evidence that the increase in cataracts in sunny parts of the world may be due to other factors, including malnutrition (diarrhoea can lead to severe demineralisation), poor diet, smoking and pollution. UVB may only pose a risk of triggering increased cataract formation in conjunction with a diet rich in unsaturated fats and their oxidised products (Cancer Res, 1985; 45: 6254-9). Those who eat a more balanced diet, supplemented with vitamins C and E, seem not to develop cataracts, even with extended exposure to UV radiation (Ophthalmology, 1998; 105: 1836; Am J Clin Nutr, 1997; 66: 911-6).
Sunscreens: help or hazard?
Commercial sunscreens, which are supposed to protect the skin, have been suspected of promoting skin cancers (see box on p 4). Researchers have found that high levels of oxybenzone, used extensively in high SPF (sun protection factor) creams can be absorbed into the body (Lancet, 1997; 350: 863-4). As this particular chemical has not been widely studied for its possible toxic effects, what this is doing to your body is anyone's guess. The Lancet report recommended that sunscreens should not be applied to large areas of the body repeatedly over extended periods of time.
Other research has found that children who use a lot of sun creams and oils are more likely to get freckles and thus may be at a higher risk of developing melanoma (J Nat Cancer Inst, 1998; 90: 1873-80).
Once again, other factors besides simple sun exposure can increase the risk of sunburn. British naturopath Harald Gaier has warned that certain drugs can increase the likelihood of sunburn (see box on p 3).
A poor diet laden with fats and processed foods may predispose a person to sunburn or other damage. In his book Sunlight Could Save Your Life (Penryn, California: World Health Publications, 1980), Dr Zane Kime is categorical: ". . . sunbathing is dangerous for those who are on a standard, high fat American diet or do not get an abundance of vegetables, wholegrains and fresh fruits".
At the end of a two year study, skin cancer patients on a low fat diet had significantly fewer lesions than those who had not changed their diet (Int J Cancer, 1995; 62: 165-9).
Indeed, the heliotherapists of the last century placed great emphasis on diet to maximise the sun's benefits. Rollier insisted that healthful meals were an integral part of treatment, suggesting that well nourished skin responds better to sunlight that mineral deficient skin.
Beneficial effects of light
Despite government warnings and the scaremongering from vested interests of the sun protection industry, there is a wealth of evidence that the sun can promote health and reduce disease, including many cancers.
One of the most important effects of the sun is synthesis of vitamin D, which cannot occur without UVB. Besides preventing childhood and adult rickets, vitamin D ensures the correct balance of calcium and phosphorus necessary for bone formation and remodelling. The body tends to make better use of photosynthesised than dietary vitamin D.
Britain has little UVB available from October to March, so it's important to get out into the sun from April to September to get through the winter. Many older people suffer from a deficiency of vitamin D, both because they aren't exposed to enough sunlight and their body is less able to utilise calcium, leading to an increased risk of fractures and osteoporosis, especially in women. A sunscreen that blocks UVB will significantly reduce vitamin D synthesis.
Tanning is not necessary since prolonged sun exposure produces no more vitamin D than short exposure.
A substance in the skin called squalene is broken down in the presence of light to form the vitamin D precursor but, in its absence, forms cholesterol instead. So, sunlight can reduce blood pressure and cholesterol, but the body needs UVB radiation to do this (Lancet, 1998; 352: 709-10).
Researchers at the Royal Infirmary in Blackburn found that lack of sunlight was a significant factor in the increased risk of heart disease (Quart J Med, 1996; 89: 579-89). In this study, gardening was linked to a lowered blood cholesterol in summer, but not in winter, suggesting that the reduced cholesterol had nothing to do with the exercise of gardening, but with being outside in the sun.
Sunshine may prevent cancer
In The Healing Sun (Findhorn Press, 1999), author Dr Richard Hobday, who has exhaustively surveyed the research, presents an array of studies showing that sunshine may reduce the incidence of various cancers, including those of the breast, colon, ovaries and prostate. It also may help to prevent diabetes, multiple sclerosis, heart disease and high blood pressure, osteoporosis, psoriasis and seasonal affective disorder (SAD).
In 1941, Dr Frank Apperly presented statistics showing that death rates for certain internal cancers increased with distance from the equator. Cancer death rates in cities at 30-40 degrees latitude in the US and Canada were, on average, 85 per cent higher than in those at 10-30 degrees latitude, increasing to 150 per cent in cities at 50-60 degrees (Cancer Res, 1941; 1: 191-5).
A review of 50 years of studies on cancer and the sun concluded that the benefits of regular sun exposure considerably outweighed the risks of accelerated ageing, non melanoma skin cancers and malignant melanoma (Prevent Med, 1993; 22: 132-40).
As for colon cancer, Drs Frank and Cedric Garland reported that its associated risk of mortality decreased in areas in the US with greater sun exposure (Int J Epidemiol, 1980; 9: 227-31). In another study, they showed that women living in areas of the US with less available sunlight had a 40 per cent higher risk of dying of breast cancer than those in Hawaii or Florida (Prevent Med, 1990; 19: 614-22). Worldwide, the lowest rates for breast and colon cancer are found in the Caribbean, South and Central America, and South Asia areas of constant sunlight. Although many other factors may be involved in these statistics, including diet and environment, the epidemiological evidence argues that a sunless existence may be unhealthy.
The skin contains melanin, a pigment that helps protect the deeper layers of the skin from the harmful effects of the sun and assists tanning. It is made from tyrosine, an amino acid required for digestive proteins, again emphasising the importance of diet to ensure an adequate supply for adequate protection.
The point is to be sensible and moderate about your exposure to sun. The dietary and environmental insults of modern life are major contributors to the incidence of both melanoma and non melanoma cancers, but the sun as UV radiation has been unjustifiably blamed by ignorant authorities and vested interests. It is time to right the balance, and restate what wiser doctors and peoples of all lands have long known sunshine is an essential nutrient and sensible sunbathing is overwhelmingly good for you.
Simon Best produces the bimonthly news report Electromagnetic Hazard & Therapy. For details, send an SAE to: Box 2039, Shoreham, West Sussex BN43 5JD or visit his website: www.emhazard therapy.com .
Dr Richard Hobday, who lives in London, offers illustrated lectures based on his book (www.healingsun.co.uk) and, with Dr Liberman, will be speaking at the LIGHT Conference in Cambridge from June 30-July 6 (www.lighttrust.co.uk or ring 10243 822 089).