Yet we know cancer to be a disease that develops slowly, over the course of many years and even decades. So when it comes to evaluating the effects of diet over longer periods, scientists must turn to other methods of investigation such as cohort studies, which track but do not change the reported diets of subjects over several years. All bear the limitations of their kind. It is not simply the number of these studies that argues so strongly for the cancer-protective potential of diets rich in these foods. Of equal importance is the fact that so many studies came to this same conclusion using different methods of investigation.
Scientific investigation is an ongoing process.
More studies on diet and cancer will be reported to the public. When it comes to something as important as personal health, the public should always look to the preponderance of scientific evidence, not simply the latest study. Evidence that has been building for decades swings heavily in favor of a long-term diet high in vegetables and fruits for reducing risk for cancer, as well as heart disease, diabetes and obesity. Ph.D. University of Louisville School of Medicine David M. Klurfeld, Ph.D. Wayne State University Laurence N. Kolonel, M.D., Ph.D. University of Hawaii at Manoa David Kritchevsky, Ph.D. The Wistar Institute Alan R. Kristal, Dr. Sushma Palmer, D.Sc.