Almost half were also unaware of the effect of obesity or age on sperm quality.

London - Regular drinking could increase by up to half the risk of developing melanoma, the most deadly form of skin cancer which affects many young people.

Those who had less than one drink a day had a 10 per cent increased risk of melanoma compared with non-drinkers or those who only drink occasionally, experts found.

Moderate drinkers, who consumed two drinks a day, had an 18 per cent higher chance of melanoma.

Heavy drinkers – consuming at least four drinks a day – were at 55 per cent extra risk, according to estimates by an international team of researchers.

One drink was defined as 12.5grams of alcohol, which is the equivalent of 1.56 units, a glass of wine or half a pint of strong beer.

The extra cancer risk may be the result of alcohol making people more reckless about protecting themselves against the sun.

But the scientists say alcohol causes biological changes that makes skin more sensitive to light and may aggravate the impact of exposure to ultraviolet light.

The researchers, whose findings are published in the British Journal of Dermatology, reviewed 16 studies involving more than 6,200 patients with melanoma. - Daily Mail