Eating Rye Bread May Reduce Cholesterol

The ability of dietary fiber, particularly soluble fibers found in cereals, to reduce coronary heart disease risk by improving serum lipid profiles has been demonstrated in several studies. The dietary fiber content of rye is 16.1 g/100 g, but its effects on blood lipids have been studied only in animal models. This study investigated the effects of increasing the amount of rye bread consumed in a daily diet on serum cholesterol levels in men and women in Helsinki, Finland, who had elevated cholesterol. Rye is a commonly used cereal in northern and eastern Europe.

Eighteen men and 22 women participated in the study. They had a baseline serum cholesterol concentration of 6.4 +/- 0.2 mmol/L. Each subject randomly consumed rye or wheat bread as 20% of their total energy intake for 4 weeks at a time, and then crossed over. There was an additional 4-week washout period between bread study periods. During the bread periods, subjects were asked to replace their customarily used breads and baked products with rye bread during the rye period and wheat during the wheat bread period. Test bread portions were 27.5-40.5 g for rye and 22.5-25.0 g for wheat. A minimum of 4-5 portions of the test breads had to be consumed each day. Fasting blood samples were collected at the beginning and the end of the bread periods.

Serum total cholesterol decreased by 8% in men during the rye bread period but did not change significantly in women. Wheat bread did not alter any of the lipid variables studied. Total cholesterol and LDL cholesterol decreased in men in a manner dependent on the amount of rye bread consumed. HDL cholesterol in men increased during the rye bread period, but not significantly. Neither type of bread altered blood levels of glucose and insulin significantly.

The significant reductions in total and LDL cholesterol observed in men were attributed to the fact that men consumed greater quantities of rye bread than women during the study. The greatest change in cholesterol levels occurred in men who ate about 8-10 slices of rye bread per day.

"In conclusion, rye bread is effective in reducing serum total and LDL cholesterol concentrations in men with elevated serum cholesterol," wrote the authors. "Good compliance with consuming a relatively large amount of rye bread in the usual diet indicates that rye bread offers a practical dietary means of reducing serum cholesterol in men."

Journal of Nutrition