Resistant starches

Initially, it was hoped that resistant starches (ie, starches that enter th e colon) would have clear advantages in the reduction of colon cancer risk and possibly the treatment of ulcerative colitis. Recent studies have confi rmed the ability of resistant starch to increase fecal bulk, to increase th e molar ratio of butyrate in relation to other short-chain fatty acids, and to dilute fecal bile acids. However, reduction in fecal ammonia, phenols, and N-nitroso compounds have not been achieved. At this point the picture f rom the standpoint of colon cancer risk reduction is not clear. Nevertheles s, there is a fraction of what has been termed resistant starch (RS1), whic h enters the colon and acts as slowly digested, or [ente, carbohydrate. Foo ds in this class are low glycemic index and have been shown to reduce the r isk of chronic disease. They have been associated with systemic physiologic effects such as reduced postprandial insulin levels and higher high-densit y lipoprotein cholesterol levels. Consumption of low glycemic index foods h as been shown to be related to a reduced risk of type 2 diabetes. Type 2 di abetes has in turn been related to a higher risk Of colon cancer, especiall y colon cancer deaths. if carbohydrate has a protective role in colon cance r prevention, it may lie in the systemic effects of low glycemic index food s. The colonic advantages of different carbohydrates, therefore, remain to be documented. However, there is reason for optimism about the possible hea lth advantages of so-called resistant starches that are slowly digested in the small intestine. (C) 2000 Lippincott William & Wilkins, Inc.