Eating salad favourite could halve the risk of skin cancer

Eating plenty of tomatoes can halve the risk of skin cancer in men, according to recent research. The healthy fruit is rich in carotenoids, potent antioxidants that mop up cell damaging molecules called free radicals.

In experiments, daily consumption of the nutritional food slashed skin tumours dramatically in male mice - but there was no effect in females. The findings, published in the journal Scientific Reports, could lead to personalised cancer prevention strategies - based on gender.

It has previously been shown male mice develop tumours earlier after exposure to ultraviolet (UV) light and they are more numerous, larger and more aggressive. Professor Tatiana Oberyszyn, a pathologist at Ohio State University, said: "This study showed us that we do need to consider sex when exploring different preventive strategies.

"What works in men may not always work equally well in women and vice versa." The discovery adds to evidence of the anti-cancer benefits of tomatoes. One study of 47,000 men showed eating tomato products ten or more times a week reduced prostate cancer risk by a third.

Co author Dr Jessica Cooperstone said carotenoids, the pigmenting compounds that give tomatoes their pretty red hue, may protect skin against UV light damage, Male mice whose daily diet was made up of 10 percent tomato powder for 35 weeks had 50 percent fewer skin tumours when they were exposed to ultraviolet light. This was compared to peers given no dehydrated tomato.

There were no significant differences in the number of tumours that developed in female mice subjected to the same study. Dr Cooperstone, of the University's College of Food, Agricultural and Environmental Sciences, said clinical trials in humans have suggested eating tomato paste over time can dampen sunburns.

She believes carotenoids from the plants that are deposited in the skin of humans after eating may be able to protect against UV light damage. Dr Cooperstone said: "Lycopene, the primary carotenoid in tomatoes, has been shown to be the most effective antioxidant of these pigments.

"However, when comparing lycopene administered from a whole food (tomato) or a synthesized supplement, tomatoes appear more effective in preventing redness after UV exposure, suggesting other compounds in tomatoes may also be at play."

But only male mice fed dehydrated red tomatoes had reductions in tumour growth. Those fed diets with tangerine tomatoes, which have been shown to be higher in lycopene in previous research, had fewer tumours than the control group, but the difference was not statistically significant.

Dr Cooperstone is currently researching tomato compounds other than lycopene that may impart health benefits. Non-melanoma skin cancers are the most common of all cancers, with more new cases - 5.4 million in 2012 - each year than breast, prostate, lung and bowel cancers combined, according to the American Cancer Society.

Despite a low mortality rate, these cancers are costly, disfiguring, and their rates are increasing. Dr Cooperstone added: "Alternative methods for systemic protection, possibly through nutritional interventions to modulate risk for skin-related diseases, could provide a significant benefit.

"Foods are not drugs, but they can possibly, over the lifetime of consumption, alter the development of certain diseases."

Skin cancer is the most common form of the disease in Britain with the number of cases soaring seven-fold in the past 40 years because of the surge in popularity of package holidays. In excess of 100,000 new cases are diagnosed every year across the UK, killing more than 2,500 people.

UV exposure is known to be the main preventable cause of skin cancer, the British Skin Foundation states on its website. Experts advise not to forsake sun cream, even when under the cover of a sun umbrella.