Consumption of diets high in whole grains has been recommended in the 2005 Dietary Guidelines for Americans and are reported to have a number of beneficial health effects including reduced risk of cancer, cardiovascular disease, and type 2 diabetes, which are leading causes of death in the USA. These results have been attributed to the effects of the soluble and insoluble fiber content of whole grain foods on risk factors for these diseases including blood glucose, insulin, and cholesterol. Other more general beneficial physiological effects of consumption of whole grains include reduced transit time which may reduce risk of colon cancer, and reduced rate of absorption of energy containing nutrients which may reduce glucose and insulin responses and risk of obesity. Numerous studies have demonstrated that whole grains that are high in soluble fibers, such as beta-glucan, found in oat and barley products are more effective in lowering blood cholesterol than those in which fibers are predominantly insoluble such as wheat or rice. Health claims that consumption of oats or barley products effectively lower blood cholesterol concentrations have been approved by the Food and Drug Administration. This claim states that consumption of oat or barley products containing a total of at least 3 grams of beta-glucan per day is necessary to observe a health benefit. Read more...