When Dr. Jim Watson speaks, people listen. But they don't always hear the right things. Many press accounts reported that Watson had said that antioxidants cause cancer. He didn't say that. He questioned the use of antioxidant supplements by people undergoing cancer treatment. Watson's words carry a lot of weight because it was he, along with Francis Crick who in 1953 produced one of the most important research papers in the history of science. Published in Nature with the simple title of 鈥淎 structure for Deoxyribose Nucleic acid,鈥� it laid the groundwork for our understanding of how the chemistry that occurs inside a cell governs life. In a classic understatement, the authors remarked that "it has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material." Indeed Crick and Watson had explained how genetic information is passed along as cells divide, and in the process made DNA a household name. Watson went on to have a stellar career playing a major role in establishing the Human Genome Project and then went on to become director of the prestigious Cold springHarbor laboratory in New York. Since 1994 his major interest has been cancer and it was his musings about its treatment that now have once again splashed his name across newspapers and webpages.
In a recently published paper in 鈥淥pen Biology,鈥� Watson deplores the lack of progress in the treatment of many cancers and implores researchers to take a different direction. The focus, Watson suggests, should be on why cancer cells do not undergo apoptosis, or programmed cell death, the the same way that various old, unnecessary, and unhealthy cells cells do. The human body replaces perhaps one million cells per second. When apoptosis does not work correctly, cells that should be eliminated may persist and become immortal, a characteristic of cancer. When apoptosis works overly well, it kills too many cells and inflicts grave tissue damage. This is the case in strokes and neurodegenerative disorders such as Alzheimer's, Huntington's, and Parkinson's diseases.
Watson argues that programmed cell death involves the formation of free radicals and cancer cells produce antioxidants that neutralize free radicals. Indeed, the reason that chemotherapy and radiation work against cancer cells is because they produce free radicals that prompt apoptosis. That鈥檚 why taking antioxidants when undergoing chemotherapy or radiation, says Watson, may actually make the situation worse. Antioxidants may well be the the proverbial double edged sword, preventing damage to DNA in healthy cells but preventing cell death in cancer cells. According to Watson, patients undergoing chemo or radioation therapy, should stay way from ingesting antioxidant supplements. He does not suggest that antioxidants cause cancer, although like many other scientists, he is underwhelmed by the supposed evidence that antioxidant supplements can prevent the disease.
Evidence is accumulating that the benefits of antioxidants have been overstated. The widely held assumption has been that the reason people who consume a diet high in fruits and vegetables are healthier is because of the increased intake of antioxidants. This argument is supported by laboratory studies in which antioxidants prevent damage to DNA in cell cultures. But conceivably, the benefits of fruits and vegetables are due to compounds other than antioxidants, or perhaps the key is not what these populations are eating but what they are not eating, namely lots of meat.
It should be remembered, though, that Watson鈥檚 article is really just an opinon piece, not backed by hard evidence. Furthermore, in no way does he suggest that eating foods with a significant antioxidant content, like blueberries, is a problem. It is at antioxidant supplements during cancer therapy that he points an accusing finger, and suggests that research should focus on anti-antioxidants for cancer treatment. Curiously, some substances that have antioxidant properties at low concentrations have anti-antioxidant, or prooxidant properties at higher concentrations. Vitamin C and uric acid are examples. When present at high concentrations, they engage in a reaction with iron in the blood to generate free radicals. There is certainly no reason to stop eating blueberries or broccoli, but when it comes to cancer treatment we may be hearing more talk of anti-antioxidants.
