Superfoods can make cancer more likely: top scientist

James Watson said the cure for many cancers will remain elusive unless scientists rethink the role of antioxidants, which include vitamin pills and food such as blueberries and broccoli.

It is widely believed they boost health and fight cancer by mopping up oxygen molecules called free radicals but Watson argues these may be key to preventing and treating cancer - and depleting the body of them may be counter-productive, the 'Daily Mail' reported.

Free radicals not only help keep diseased cells under control, they are also pivotal in making many cancer drugs, as well as radiotherapy, effective, he claimed.

The 84-year-old Nobel laureate stated that antioxidants "may have caused more cancers than they have prevented".

"For as long as I have been focused on the curing of cancer, well-intentioned individuals have been consuming antioxidative nutritional supplements as cancer preventatives, if not actual therapies," he said.

"In light of recent data strongly hinting that much of late-stage cancer's untreatability may arise from its possession of too many antioxidants, the time has come to seriously ask whether antioxidant use much more likely causes than prevents cancer," he wrote in a study published in the journal Open Biology.

A vast number of studies had found antioxidants including vitamins A, C and E and the mineral selenium, to have "no obvious effectiveness" in preventing stomach cancer or in lengthening life, Watson claimed.

Instead, they seem to slightly shorten the lives of those who take them, and vitamin E may be particularly dangerous.

Professor Nic Jones, of Cancer Research UK, agreed that studies showed antioxidants were ineffective for cancer prevention in healthy people and can even slightly increase the risk of the disease.

He said vitamins and minerals should be obtained through a healthy and balanced diet.