Policosanol's lipid-lowering activity doubted

By Stephen Daniells

- Last updated on GMT

Related tags: Clinical trial, Cholesterol

The ability of the waxy sugar-cane extract, policosanol, to reduce
LDL-cholesterol levels have been called into doubt by a new
clinical trial, but a poor delivery system undermines the studies'
conclusions, says industry.

Policosanols are waxy, mostly linear C20 to C34 alcohols, and can be extracted from beeswax and a range of plant sources including sugar cane, rice bran, green vegetables, wheat bran and saw palmetto. The extract is sold in over 40 countries worldwide.

Clinical trials from Cuba in 2001 reported that policosanols extracted from sugar cane could reduce cholesterol levels by 10 to 30 percent, and further studies from the same research group and sponsored by the same enterprise have continued to report LDL-cholesterol activity of similar magnitude. Further studies, however, have yielded mixed results.

"Our trial is the first study to investigate sugar-cane derived policosanol independently from the aforementioned Cuban research group but still using Cuban policosanol,"​ said lead author Heiner Berthold from the Drug Commission of the German Medical Association.

The new study, published in this week's issue of the Journal of the American Medical Association​ (Vol. 295, pp. 2262-2269), reports the results of a randomized, double-blind, placebo-controlled, parallel-group trial of 129 volunteers with high LDL-cholesterol levels (baseline levels of 150 milligrams per litre).

Volunteers were randomly assigned to one of five supplementation groups to receive 10, 20, 40 or 80 milligrams per day of policosanol, provided by Dalmer Laboratories (the same company that provided the policosanol for the positive Cuban trials, extracted from sugar cane), or placebo.

No formulation, dispersion or delivery details are provided other than the policosanol was provided as film-coated tablets manufactured by Madaus AG, Germany.

After 12 weeks of intervention the researchers reported: "Our rigorously controlled trial found no effect of Cuban sugar cane-derived policosanol on lipoprotein levels in patients with hypercholesterolemia or combined hyperlipidemia beyond placebo."

No significant difference was found for any of the doses of policosanol for any of the lipoprotein variables, such as LDL-cholesterol, HDL-cholesterol, total cholesterol, triglycerides, and VLDL-cholesterol.

The researchers call into question the Cuban research by saying: "Almost all [Cuban] studies [into policosanol] were supported by one sponsor, Dalmer Laboratories, a commercial enterprise founded by the Center of Natural Products, Cuba, to market policosanol."

Therefore, independent studies are required to test the validity of the lipid-lowering claims associated with policosanol. A Dutch trial, published in 2004 (Metabolism​, Vol. 53, pp. 1309-1314), also challenged the Cuban results, but this trial used a wheat germ-derived policosanol.

The results of this study, which have been picked up by national and international news media, may appear to be damaging to the policosanol industry, but Rudi Moerck, president of Valensa, who recently introduced nano-dispersed policosanol to the market, said the results are not unexpected considering the delivery system used.

Moerck told NutraIngredients-USA.com that while the new study was a "model study"​ with excellent research protocol, there was "one gigantic flaw."

The researchers do not provide any details on how the tablets were formulated, said Moerck, and that when policosanol is used as a globular material it has a very low surface area with a melting point of over 70 degrees Celsius.

"They didn't do enough work on delivery. It's a formulation science problem,"​ said Moerck.

Moerck quoted the Dutch research, by Unilever scientist Yuguang Lin, which reported 97 per cent of orally administered globular policosanol went out with the stool, showing that there was only minimal absorption.

Optimizing the delivery of policosanol is the philosophy behind Valensa's Nanocosanol, introduced only last week at the Vitafoods expo in Geneva. By taking the policosanols down to the nano-scale, Valensa hopes to improve the bioavailability of the extract.

Valensa is currently conducting its own clinical trial using Nanocosanol and expects results in about 90 days. Moerck also said that Valensa would like to be involved with the German research group behind the new JAMA study, but this time using Valensa's nano-dispersed policosanol.

Daniel Fabricant, VP of scientific affairs at the National Nutritional Foods Association (NNFA) told NutraIngredients-USA.com that the study needed to be put in context.

"There is a body of clinical evidence that exists and obviously one study will in no way complete the evolving research picture regarding policosanol,"​ said Fabricant,"Considering that there is [some] evidence for HMG-CoA reductase activity and that a simple bioassay was not performed to demonstrate activity of the test material is unsatisfactory,"​.

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