Food, nutrition and prevention of cancer: evidence in Japan and future prospects

Abstract

Here, we review recent evidence concerning nutrition- and diet-related risk factors for cancer. We then discuss issues and future prospects for cancer prevention and control from the perspective of life course.

“Cancer Prevention Recommendations for Japanese” is a guide developed by the National Cancer Center of Japan, based on guidelines for potential cancer risks derived from systematic reviews and summaries of existing research conducted among Japanese. These reviews and summaries were evaluated for their reliability as scientific evidence and the strengths of association between risk factor and specific cancers. Risk factors in the guidelines which related to diet and nutrition were “alcoholic drinks”, “salt and salted foods”, “fruits and vegetables”, “physical activity”, and “body mass index”. These factors were attributed as the leading causes of cancer (Population Attributable Fractions) in Japanese, following smoking and infections, the two main causes.

Since its initial publication in 2007 by the World Cancer Research Fund/American Institute for Cancer Research, the “Second Expert Report: Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective” has been continuously updated. This Continuous Updating Project has evaluated risk factors which showed weak associations among the current Japanese population, or which have not been evaluated because of a lack of research.

The results of translational research, namely research which evaluates and publishes current knowledge, are important when determining priorities in solving issues of disease prevention. For future resolution of cancer prevention and control from the perspective of life course, two points are important: 1) promotion of ongoing research into known cancer risk factors, including methods of measurement and utilization; and 2) monitoring of young generations in terms of diet and lifestyle change, especially for factors which are considered to be cancer risks internationally. Cancer prevention and control through the life course is especially important, given that cancer develops over an extended period. Risk communication to promote ideal lifestyle decisions for diet and nutrition based on current evidence among Japanese is important. In addition, it may also be important to monitor internationally identified hazard factors which have the potential to become risk factors in Japanese.