OATS AS A FUNCTIONAL FOOD FOR HEALTH

Authors: BEHALL, KAY; HALLFRISCH, JUDITH - RETIRED, BHRNC, DHPL

Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Book / Chapter
Publication Acceptance Date: 11/16/2006
Publication Date: N/A
Citation: N/A

Interpretive Summary: The book chapter reviews the effectiveness of grains containing soluble fiber in reducing major health risk factors. Epidemiologic studies reported that diets rich in whole grains may protect against hypertension, stroke, cardiovascular disease, and Type 2 diabetes. Studies show that grains containing a high amount of soluble fiber, such as oats or barley, are more effective in lowering blood cholesterol in animals and humans than are grains containing predominantly insoluble fibers, such as wheat or rice. Oats and oat bran have been used successfully to lower blood lipids and have been promoted as lipid-lowering foods. The amount of oats or oat bran consumed, initial blood lipids concentration and age of the population studied may have played a role in the presence or absence of beneficial lipid lowering effects. On the basis of epidemiologic and clinical study results suggesting that oats are effective in lowering blood cholesterol levels, the U.S. Food and Drug Administration (2001) has allowed a health claim for oats and soluble fibers from oats. The recommended effective level of consumption is a minimum of four servings per day, each containing at least 0.75 g of soluble fiber for an intake of at least 3 g of soluble fiber per day from oats. A diet low in saturated fat and cholesterol in conjunction with the soluble fiber intake was recommended to reduce the risk of heart disease. Oats, barley and their soluble fiber extracts have been reported to have beneficial effects on glucose tolerance, especially with regard to the magnitude of postprandial glucose and insulin response. Beneficial health effects also include reduced insulin resistance, improved glycemic control in diabetes, and potentially decreased the risk for development of diabetes. Insulin resistance has been associated with in the development of Type 2 diabetes mellitus, obesity, hypertension and ischemic heart disease independently and as part of the metabolic syndrome. The beneficial effects of consuming oat or barley or their soluble fiber extracts are most likely occur in subjects whose elevated glucose and insulin can be modified by diet; that is, individuals who are older, overweight, or have Type 2 diabetes. The effects of soluble fibers on blood pressure are less well described. In individuals at risk for cardiovascular disease, Type 2 diabetes or hypertension, consumption of a healthy diet high in fiber from oat can lower total and LDL cholesterol, glucose, insulin and systolic and diastolic blood pressure. This review of grains high in soluble fiber is important to scientists, the general public and to health care professionals working with subjects and individuals with diabetes or coronary heart disease.

Technical Abstract: Epidemiologic studies reported that diets rich in whole grains may protect against hypertension, cardiovascular disease and Type 2 diabetes. Studies show that grains containing soluble fiber, such as oats, are more effective in lowering glycemic response, insulin resistance, and blood cholesterol in animals and humans than are grains containing predominantly insoluble fibers, such as wheat or rice. Based on epidemiologic and clinical studies reporting lower cholesterol levels after chronic consumption of oats, oat bran or oat fiber extracts, the U.S. Food and Drug Administration has allowed a health claim for oats and oat fiber extracts based on the soluble fiber (beta-glucan) content. The effects of soluble fibers on blood pressure are less well described. The amount of oats, oat bran or oat soluble fiber consumed, initial blood glucose, insulin or cholesterol concentrations and age of the population play a role in the magnitude of the reductions observed. In individuals at risk for cardiovascular disease, Type 2 diabetes or hypertension, consumption of a healthy diet high in fiber from oat can lower total and LDL cholesterol, glucose, insulin and systolic and diastolic blood pressure.