Eight-week randomized cross-over studies in three separate groups of 10 healthy volunteers were undertaken to determine the effects of daily dietary supplementation with pectin (12 g/day), cellulose (15 g/day) and lignin (12 g/day) on serum lipid levels. Detailed dietary records were kept throughout the study and there was no significant change in dietary intakes except for the fiber supplement. Neither pectin, cellulose, nor lignin significantly altered serum total cholesterol, triglycerides, high-density lipoprotein cholesterol, or the ratio of high-density lipoprotein to total cholesterol in healthy normolipidemic subjects over four weeks.