A group of British doctors came under fire yesterday for suggesting that sunshine might be more healthy than harmful.
The four Bristol University researchers were accused of undermining years of public health work aimed at convincing people of the dangers of too much sun.
Experts agree that exposure to the sun's ultraviolet rays increases the risk of skin cancer and cataracts and accelerates the signs of ageing.
Organisations such as the Health Education Authority and Cancer Research Campaign have repeatedly emphasised the importance of staying in the shadows or covering oneself with sunscreen.
But in the British Medical Journal yesterday the Bristol team led by epidemiologist Dr Andrew Ness wrote: "There is evidence that the potential benefits of exposure to sunlight may outweigh the widely publicised adverse effects on the incidence of skin cancer."
The researchers argued that the chances of dying from skin cancer as a result of too much sun were slight.
On the other hand, sunshine had a number of well-known health effects. Vitamin D, made in the body in reaction to sunlight, prevented rickets in children and was associated with a protective effect against heart disease.
Sunshine was also useful for treating certain skin conditions, such as psoriasis, and there was evidence that it reduced the incidence of multiple sclerosis.
There was also the "feelgood" effect of lying or sitting in the sun - a benefit to mental health which should not be ignored.
The researchers thought it premature to advise people to increase the length of time they spent in the sun, but suggested that the basis of the current cover-up advice should be reviewed and more research carried out.
They added: "Perhaps, while we await the conclusions of such formal analyses, those of us who enjoy spending time in the sun can rest (on our deck chair, sun lounger or whatever) assured that the chance that we will be one of the people dying from our tan is small."
The article was strongly criticised by health campaigners who claimed it was unbalanced and not backed by scientific evidence.
The Health Education Authority pointed out that skin cancer was the most common form of cancer in the UK, with more than 50,000 new cases diagnosed each year and more than 2,000 people dying from the disease.
Treatment almost always required surgery, and almost 50% of malignant cases were fatal.
HEA skin cancer campaign manager Christopher New said: "Trying to persuade the public to give up something they enjoy for the good of their health is a slow and arduous task. It has taken many years to change people's attitudes to sunbathing.
"We are very disappointed with this controversial article. It has scant supporting evidence and it runs the risk of undoing many years of good health education."
Dr John Toy, medical director at the Imperial Cancer Research Fund, said: "Sunshine is good for you in moderation, but too much could kill you.
"We recommend a happy, healthy balance. Most people do get enough sunlight to obtain these beneficial effects - the main point is that to reap the benefits you don't need to burn and therefore expose yourself to dangerous risks."