ity of Bristol in southwestern England triggered a barrage of criticism with their report published in The British Medical Journal. While not suggesting people rush out to get the perfect tan, they said the public should be more aware of the beneficial effects of the sun. "There is evidence that the potential benefits of exposure to sunlight may outweigh the widely publicised adverse effects on the incidence of skin cancer," Ness said in the journal. The researchers cited vitamin D, which the body produces after exposure to sunlight, for its protective effect against heart disease and said the sun also has a positive influence on mental health. But cancer experts described the report as irresponsible and said there was insufficient scientific evidence to support the arguments behind it. "I think it is a great shame that this discussion has been brought into the public arena. The argument they are putting forward does not have enough scientific evidence to justify the damage it could potentially cause by suggesting going out in the sun is healthy," Dr Joanna Reynolds, of the Cancer Research Campaign, told Reuters. Scientists and doctors have been warning the public for years about the sun and its links to skin cancer, one of the most common causes of cancer death in the 25-29 age group. Cases of the disease are expected to rise until the depletion of the earth‘s protective ozone layer is halted. Cancer experts fear that the report and the media attention it has generated could undo everything they have been trying to achieve. Dr John Toy, the medical director of the Imperial Cancer Research Fund, said sunshine in moderation is good but too much can kill. "UV (ultraviolet light) is good for some skin disorders, improving bone density and psychological well being but excessive exposure leads to skin damage and can cause fatal skin cancer. We recommend a happy, health balance," he said. In addition to heart disease and mental health, Ness and his colleagues said UV light, both natural and from medical sources, is used to treat skin conditions such as psoriasis and a disease called multiple sclerosis. Toy and Reynolds said most people already get enough sunlight to reap the benefits and should not expose themselves to dangerous risks. The doctors said they are not advising people to stay out of the sun completely but to be careful about how they expose themselves. People with fair hair and skin and those with freckles should take extra precautions.