Submitted to: United States-Japan Cooperative Program in Natural Resources
Publication Type: Proceedings
Publication Acceptance Date: 12/11/2004
Publication Date: 12/11/2004
Citation: Behall, K.M. 2004. Health effects of barley consumption. United States-Japan Cooperative Program in Natural Resources. Honolulu, Hawaii, December 11-18, 2004. Interpretive Summary: Cardiovascular disease remains the major health problem in the US even though fat intake has declined in response to recommendations of health organizations. Consumption of soluble fiber, like that in oats, has been recognized as beneficial in decreasing blood cholesterol levels and other cardiovascular risk factors. Barley contains high amounts of soluble fiber but is not consumed as extensively as oats in the US diet. This review summaries two studies which investigated whether consumption of barley would reduce cardiovascular risk factors similarly to the reduction observed after oats. Moderately hypercholesterolemic men and women initially consumed a Step 1 diet to adjust the subjects to a lower fat, higher fiber diet than is typically consumed by the U.S. population. Three diets with similar total dietary fiber were fed for 5 weeks each. Only test foods made with whole wheat or brown rice (low), ½ whole wheat/ brown rice and ½ barley (mid) or only barley (high) varied between the diets. Total lipids were determined enzymatically and lipid subclass fractions were measured by nuclear magnetic resonance spectroscopy. Compared with prestudy concentrations, total cholesterol after the low-, medium-, and high-soluble fiber diets was 14%, 17%, and 20%, respectively, lower in Study 1 and 4%, 9%, and 10%, respectively, lower for all subjects in Study 2. In Study 2, men had the greatest percent decrease (14.5%) after consuming the high ß-glucan diet, followed by the postmenopausal women (10.7%) and the premenopausal women (8.4%). LDL cholesterol concentrations followed the same significant pattern of reduction that was observed for total cholesterol. In both studies the ratio of total cholesterol to HDL cholesterol was highest after the low soluble fiber diet. HDL cholesterol and triacylglycerol concentrations after three diets were not significantly different. No gender difference was observed. LDL particle size did show a significant variation between the diets but no difference was observed due to the amount of soluble fiber in the diet. Overall the subjects' cardiovascular risk factors improved with decreased total cholesterol, LDL and total cholesterol/HDL cholesterol ratio; the higher soluble fiber intake having the greatest effect on total and LDL cholesterol. The American public will benefit by having another food source containing soluble fiber that can be included in a healthy diet to reduce cardiovascular risk.
Technical Abstract: Cardiovascular disease remains the major health problem in the US. Consumption of soluble fiber, like that in oats, has been recognized as beneficial in decreasing blood cholesterol levels and other cardiovascular risk factors. Barley has high amounts of soluble fiber but is not extensively consumed in the US diet. This study investigated whether consumption of barley would reduce cardiovascular risk factors comparably to reductions observed with other soluble fiber sources. Moderately hypercholesterolemic subjects consumed controlled step one diets for 17 wk. After a 2 wk adaptation period, whole grain foods containing 0, 3, or 6 g soluble fiber/day from barley were included in the step one menus. Diets were consumed for 5 wk each and fed in a Latin square design. Total cholesterol and low density lipoprotein (LDL) was significantly lower when the diet contained 3 or 6 gm of ß-glucan from barley, the greatest change occurring in the men and postmenopausal women. High density lipoprotein (HDL) and triacylglycerol concentrations did not differ among the three levels of dietary ß-glucan. Large LDL particle size significantly decreased when whole grains were incorporated into the three diets. Postmenopausal women had significantly higher LDL particle size. These results indicate that barley may be an effective addition to a healthy diet to lower total and LDL-cholesterol in both men and women.