CIMMYT Series on Carbohydrates, Wheat, Grains, and Health: Carbohydrates, Grains, and Whole Grains and Disease Prevention. Part IV. Cancer Risk: Lung, Prostate, and Stomach1,2 To address current claims that discourage ingestion of carbohydrates (CHOs), wheat, and cereal grains, as well as to celebrate the versatility, nutritional and health benefits, and contribution of these foods to the world food supply, we felt compelled to defend their role in the diet and write a series of reviews. The eighth review in this series examines scientific research findings on the impact of whole and refined grains and the CHOs they contain on three common cancers: lung, prostate, and stomach. The totality of the data indicates total CHO intake is not related in most cohorts to risk for these cancers. The few studies conducted on the role of dietary fiber in lung cancer show that low CHO and dietary fiber intakes may increase risk. For prostate and stomach cancers, cereal fiber intake specifically has been associated with reduced risk. The effects of refined grains or specific grain-based foods on lung cancer are unclear. For prostate cancer there may be a weak association between increased risk and refined grain and bread consumption. For stomach cancer there seems to be less risk associated with whole grain intake and increased risk associated with diets high in refined grains and low in fruits and vegetables. When considered as a whole, the evidence appears to support several general dietary recommendations. For diets in which calorie intake matches energy needs, food groups are represented in recommended amounts, and there is a mix of whole and refined staple grains, there seems to be less risk for developing certain cancers. Adequate dietary fiber from this balance of foods positively impacts the immune system, microbiome, gut transit, and colonic fermentation, which significantly contributes to general health and decreased cancer risk. |