Is there a role for hibiscus to lower cholesterol?

Not according to researchers at St. John’s National Academy of Health Sciences, in Bangalore, India.

First, the details.

  • 60 people with LDL (bad) cholesterol blood values between 130-190 mg/dL and no history of coronary heart disease were randomly assigned to a treatment group.
    • 1 gm of Hibiscus sabdariffa leaf extract for 90 days
    • Placebo (a similar amount of maltodextrin)
  • In addition, everyone was given dietary and physical activity advice for the control of their blood lipids.
  • Anthropometry (size, weight,  proportions), blood biochemistry, diet, and physical activity were assessed at the start of the study and at days 45 and 90.
  • Neither the patients nor researchers knew the treatment given — double blind.

And, the results.

  • Body weight, blood levels of  LDL cholesterol and triglycerides decreased in both groups, but there were no significant differences between the groups.

The bottom line?

It’s likely that the results of this study were a due to following the standard dietary and physical activity advice.

The authors concluded, “At a dose of 1 gm/day, H. sabdariffa leaf extract did not appear to have a blood lipid lowering effect.”

These findings contradict the results of a laboratory study published earlier this year. In that study, researchers at Naresuan University, in Phitsanulok, Thailand reported, “The potency of extracts from H. sabdariffa… [was] similar to 0.4 mcg/mL [of the statin] pravastatin [Pravachol] in inhibiting HMG-CoA reductase and possibly reduced cholesterol biosynthesis.”

Possible reasons for the failure to lower cholesterol by H. sabdariffa in this study include incorrect dosage or poor formulation that failed to release the active ingredient. Or, maybe it just doesn’t exert a cholesterol-lowering effect at well-tolerated doses.

7/21/10 21:42 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.