A study by Cancer Research has revealed that around 40 per cent of cancers in women and 45 per cent of those in men could be prevented by healthier lifestyles.

In total, the charity estimates that around 134,000 people in the UK could avoid cancer by adjusting their lifestyles by quitting smoking, cutting down on alcohol, improving their diets and exercising more.

According to the report, which is published in the current issue of British Journal of Cancer, smoking is the most important lifestyle factor causing 23 per cent of cancers in men and 15.6 per cent in women - nearly one in five of all cancers.

Diet and exercise are identified as major factors in preventing obesity - another leading cause of cancer.

Professor Max Parkin, epidemiologist at Queen Mary, University of London and one of the study authors, said: "Looking at all the evidence, it's clear that around 40 per cent of all cancers are caused by things we mostly have the power to change.

"We didn't expect to find that eating fruit and vegetables would prove to be so important in protecting men against cancer. And among women we didn't expect being overweight to have a greater effect than alcohol."