WHEAT BREAD SUPPLEMENTED WITH DEPOLYMERIZED GUAR GUM REDUCES THE PLASMA-CHOLESTEROL CONCENTRATION IN HYPERCHOLESTEROLEMIC HUMAN-SUBJECTS

Recent human studies have shown that the physiologic effects of guar g um are not diminished by partial depolymerization of its galactomannan fraction. We evaluated the effect of depolymerized guar galactomannan on fasting plasma cholesterol and triacylglycerol concentrations in h ealthy volunteers with moderately raised plasma cholesterol concentrat ions (range: 5.2-8.0 mmol/L). This study was designed as a randomized, double-blind crossover of two 3-wk feeding periods separated by a 4-w k washout period. Control and guar wheat breads were prepared by a com mercial bread-making process. Subjects (n = 11) were asked to replace their normal bread with that provided, receiving control bread for one 3-wk period and guar bread for the other period, without altering the ir baseline diet. Subjects recorded their intake of foods for 6 consec utive days on three occasions during the study. Fasting venous blood s amples (10 mL) were taken from subjects on two consecutive mornings at the start and end of each feeding period. No significant changes in b ody weight or dietary intake were recorded in the control and guar bre ad periods. There was a significant reduction (10%) in total plasma ch olesterol concentration after the guar treatment (P < 0.001), mainly b ecause of a reduction in the low-density-lipoprotein-cholesterol fract ion. No changes in plasma high-density-lipoprotein-cholesterol or tria cylglycerol concentrations were seen. The cholesterol-lowering effect of partially depolymerized guar gum appears to be of a magnitude simil ar to that of high-molecular-weight guar gum used in earlier studies.