'Orange, lemon can prevent cancer'

Researchers from Johns Hopkins Institute in Baltimore have confirmed that in mice at least, vitamin C and potentially other antioxidants can inhibit the growth of some cancer tumours, reports Sanchita Sharma.

Nearly 30 years after Nobel laureate US biochemist Linus Pauling suggested that vitamin C supplements can prevent cancer, researchers from Johns Hopkins Institute in Baltimore have confirmed that in mice at least, vitamin C and potentially other antioxidants can inhibit the growth of some cancer tumours.

Conventional wisdom has it that antioxidants mop up volatile oxygen free radical molecules and prevent DNA damage associated with degenerative diseases associated with aging, such as cancers, cardiovascular disease, cognitive impairment, Alzheimer’s disease, immune dysfunction, cataracts and macular degeneration.

The Hopkins study, however, found that the antioxidants’ actual role is to destabilise a tumour’s ability to grow under oxygen-starved conditions.

The work, led by Dr Chi Dang, professor of medicine and oncology at Johns Hopkins, is published in the medical journal Cancer Cell.

So far, studies linking antioxidants to cancer prevention have been conflicting. “Research has conclusively linked diet and lifestyle with some cancers such as those of the uterus, breast, colon and stomach, but there is no conclusive proof that antioxidants can be prescribed for cancer prevention.

“However, vitamin C and other antioxidants are good for health and boost immunity, we ask cancer survivors to include a lot of fresh fruits and vegetables in their diet,” says Dr Sameer Kaul, senior consultant in oncology, Apollo Hospital.

When it comes to boost antioxidant intake, food sources of antioxidants are better than diet supplements, health newsletter Mayo Clinic Health Letter said, quoting recent research. The best-known food components with antioxidant activities are vitamins A, C, and E; i-carotene; the mineral selenium; and the compound lycopene.

“Many antioxidants can be identified in food by their distinctive colours the deep red of cherries and of tomatoes; the orange of carrots; the yellow of mangos; and the blue-purple of red cabbage, plums, blackberries (jamun), brinjal and red grapes. Purple, in fact, is considered the best source of antioxidants,” says nutritionist Rekha Sharma, senior vice president, VLCC Healthcare.