Antioxidants may cause more harm than good, says Nobel laureate

Many people take antioxidant products such as vitamins C and E or eat antioxidant-rich foods such as blueberries. Doing so may, however, be causing more harm than good, according to an idea proposed by Nobel Prize winner Prof James Watson.

The co-discoverer of the structure of DNA was speaking today to an invited audience of scientists at Trinity College Dublin. He raised eyebrows with his proposal that reactive oxygen may actually help suppress cancers, type II diabetes and Alzheimer’s disease rather than cause damage.

He acknowledged his idea “is against conventional wisdom”, but he argues there is as yet untested evidence suggesting he may be correct.

His controversial theories have yet to tested by scientific research.

Yet he has had a long-standing interest in cancer research and is the Oliver Grace Professor of Cancer Research at Cold Spring Harbour Laboratory, New York. Despite decades of research, cancer mortality has remained stubbornly high with the exception of blood cancers. “Why?” was the simple question he asked. “The public is constantly being fed ’we are making all these advances’ but we are not getting very far,” he said.

Chemotherapy killed cancer cells by causing reactive oxygen to form but its effect diminishes, Prof Watson said. The tumour cells fight back by releasing antioxidants to block the damage. “If you are going to cure it then you are going to have to get rid of the antioxidants.”

He submitted a paper to the New England Journal of Medicine . It was refused the journal said "because we only publish facts not ideas", Prof Watson said. "I guess they thought the idea was too controversial."

The US currently spends up to $40 billion a year on antioxidant products, but “are the antioxidants making it more difficult to treat cancer?”

He pointed out that exercise triggers the release of reactive oxygen. “People who walk all the time should die.” Yet we know that they don’t and that a lack of exercise can increase the risk of developing type II diabetes, he said. Regular exercise has been shown to reduce the risk of diabetes and can improve memory in Alzheimer’s patients.

Regular exercise was also associated with reduced cancer risk, he said. “What it means to me, oxygen species are doing something necessary where if you don’t have them you get diabetes.”

Taking antioxidants may therefore be working against these disease-blocking processes, he suggests. Yet his ideas have not been well received. “Right now I am feeling slightly lonely,” he said.