Some of the world's leading experts in nutrition epidemiology have cast a resounding vote in the decades-long debate between treating or preventing cancer: Prevention wins.
Their report, being released today, argues strenuously for diet and exercise as the keys to fighting cancer. It calls research and spending on the treatment of cancer "necessary but not sufficient," and contends that a far better strategy for reducing the world's annual tally of 11 million cancer cases would be to develop a public-health policy aimed at preventing people from getting the disease in the first place.
The report, issued by the World Cancer Research Fund/American Institute for Cancer Research, is based on an exhaustive review of nearly 7,000 scientific studies into whether cancer rates are influenced by diet, obesity and exercise.
Based on this review, it concludes that cancer "is mostly preventable," estimating that about one-third of all cases in advanced countries like Canada could be eliminated by diets that aren't loaded with fatty, sugary foods, by people exercising regularly and, if they are obese, by slimming down to an appropriate weight. Among the cancers with links to these factors are those of the breast, prostate, mouth and colon.
"It's a very compelling case" that cancer incidence could be cut dramatically through prevention, said Shiriki Kumanyika, an epidemiologist at the University of Pennsylvania in Philadelphia and a member of an expert panel that oversaw the writing of the report. Also on the panel were such nutrition luminaries as the Harvard School of Public Health's Walter Willett.
Dr. Kumanyika said scientific evidence strongly supports the estimate that poor diet, obesity and lack of exercise cause one out of three cancers. "I definitely feel confident that it's at least that much," she said.