Newly published research has suggested that sunshine may protect against diabetes and weight gain.
The claim comes from a study where scientists found that overfed mice with fur shaved to expose their skin were slower to gain weight after basking in ultraviolet (UV) light, the same rays that make up sunshine.
They also displayed fewer of the warning signs of diabetes, such as abnormal blood sugar levels and resistance to the hormone insulin.
The benefits of UV treatment were linked to nitric oxide, a compound released by the skin after exposure to sunlight.
Applying a cream containing nitric oxide to the skin of mice was found to have the same effect on weight gain.
However, vitamin D, also produced in the skin by the action of sunlight, played no role, said the scientists.
Dr Richard Weller, from the University of Edinburgh, who took part in the Australian-led study, said: “We know from epidemiology studies that sun-seekers live longer than those who spend their lives in the shade. Studies such as this one are helping us to understand how the sun can be good for us.
“We need to remember that skin cancer is not the only disease that can kill us and should perhaps balance our advice on sun exposure.”
Previous studies in people have shown that nitric oxide can lower blood pressure after exposure to UV lamps.
Co-author Professor Martin Feelisch, from the University of Southampton, said: “These observations further indicate that the amounts of nitric oxide released from the skin may have beneficial effects not only on heart and blood vessels but also on the way our body regulates metabolism.”
The research is published in the journal Diabetes.