Long-term effects of guar gum on blood lipids.

While guar gum has been shown to lower total cholesterol and low density lipoprotein cholesterol (LDL-C) in diabetic patients over the short-term, the long-term effects are less well studied and may be unpredictable. Granola bars with and without 6.6 g guar gum were developed and fed to 16 adult volunteers with Type II diabetes mellitus who had been randomized in a double-blind fashion into guar and placebo groups of equal size. Four to six bars were consumed daily with an ad lib diet over a 6-month period. Total cholesterol, total high density lipoprotein cholesterol (HDL-C), subfractions HDL2-C and HDL3-C, LDL-C, and beta-apoprotein were measured at 0 and 6 months. Although LDL-C was lower and triglycerides higher at 6 months than at baseline, these changes were of equal magnitude and direction in both guar and placebo groups. Using each subject as his own control, only the change in triglycerides was statistically significant (P less than 0.025). When male subjects alone were analyzed, the guar group showed a statistically significant decrease in LDL, while the placebo group did not. Other lipid parameters were not significantly changed during the study, despite a positive effect on carbohydrate metabolism from the guar bars. The data suggest either that the hypolipemic effects of guar gum in patients with Type II diabetes mellitus are not sustained for 6 months, or the effects occur only in men.