Effect of combining viscous fibre with lovastatin on serum lipids in normal human subjects

Soluble fibre supplements are recommended to reduce the levels of low-density lipoprotein cholesterol (LDL-C). Limited information exists on the interaction between fibre and hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). The purpose of the present study was to evaluate the per se effect of psyllium (10 g/day) and lovastatin (20 mg/day) alone and in combination on serum lipids in normal human volunteers.

In a 4-week open label, randomised, parallel study, subjects were randomised to receive 20 mg of lovastatin, 10 g of psyllium or 20 mg of lovastatin plus 10 g of psyllium in evening daily. Levels of total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C), TC/LDL-C ratio, LDL-C/HDL-C ratio and triglycerides were determined after 1, 2, 3 and 4 weeks of treatment.

The study group comprised 36 adult, male subjects. All treatments were well tolerated, and after 4 weeks the mean LDL-C, TC and TG levels in the group receiving 20 mg of lovastatin plus 10 g of psyllium fell by 30.88%, 26.88% and 26.21% from baseline, compared with 24.78%, 19.55% and 32.88% in the group receiving 20 mg of lovastatin and 3.58%, 2.90% and 10.95% in the group receiving 10 g of psyllium respectively. Although additive effect was observed in the group receiving combination compared with group receiving lovastatin, the observed difference was not statistically significant. No significant changes from baseline in HDL-C levels occurred.

Psyllium soluble fibre should be considered as a safe and well-tolerated dietary supplement option to enhance cholesterol lowering.