The study by researchers at Laval University in Quebec will monitor the effects of chocolate consumption on fair-skinned volunteers between the ages of 25 and 65, each of whom will be prevailed upon to eat three squares of chocolate per day for 12 weeks.

Earlier research in Germany and Britain has found that chemicals in chocolate called polyphenals increase blood flow close to the skin, which helps protect against ultraviolet rays, but those studies were too small in scale to be conclusive.

The scientists at Laval University's Institute of Nutraceuticals and Functional Foods hope to confirm the link in a study of 60 people, about half of whom already have been recruited, they said.

Test subjects who have been fed chocolate are to be exposed to ultraviolet rays in a laboratory and their skin then checked for sun damage. A control group will be given a placebo.

Scientists said the study will only include female participants so that researchers can control for the variability between the body's natural hormones in men and women.