Method of administration influences the serum cholesterol–lowering effect of psyllium

To determine whether psyllium must be mixed with food to lower serum cholesterol, 18 modestly hypercholesterolemic subjects were studied for three 2-wk periods, in random order, separated by a 2-wk return to a National Cholesterol Education Program Step 2 diet. Compared with values for subjects consuming control wheat-bran cereal (63 g/d), after 2 wk of 54 g psyllium-enriched cereal/d containing 7.3 g psyllium, serum total, LDL, and HDL cholesterol, respectively, were reduced by 8% (6.15 ± 0.15 vs 6.71 ± 0.19 mmol/L, P < 0.01), 11% (4.24 ± 0.15 vs 4.78 ± 0.19 mmol/L, P < 0.02), and 7% (0.99 ± 0.05 vs 1.07 ± 0.05 mmol/L, P < 0.01). When 7.6 g of the same type of psyllium as in the test cereal was taken between meals, serum total (6.50 ± 0.19 mmol/L), LDL (4.50 ± 0.21 mmol/L), and HDL (1.06 ± 0.06 mmol/L) cholesterol were no different from control values, and total cholesterol was greater than after psyllium cereal (P < 0.05). We conclude that psyllium must be mixed with foods to have the maximum effect on serum cholesterol.