Policosanol as a dietary supplement
Policosanol is a dietary supplement derived from a mixture of waxy substances, primarily obtained from sugarcane. It is commonly promoted for its potential benefits in managing high cholesterol levels, with some studies suggesting it may have effects similar to statin medications. In addition to cholesterol management, policosanol has been explored for various other uses, including potential benefits for intermittent claudication, sports performance, and even conditions like Parkinson's disease. However, while initial clinical trials primarily conducted by a Cuban research group indicated positive outcomes, subsequent independent studies have raised significant doubts about its effectiveness in lowering cholesterol. Products marketed as policosanol in the United States are often derived from beeswax or wheat germ, differing in composition from the sugarcane version and lacking robust research support. Reports of side effects are generally mild, yet there are concerns regarding interactions with blood-thinning medications and certain other drugs. Due to these mixed findings and safety considerations, consulting a healthcare professional before starting policosanol is strongly advised. Overall, more independent research is necessary to validate the claims surrounding policosanol and its efficacy as a dietary supplement.
Policosanol as a dietary supplement
DEFINITION: Natural substance promoted as a dietary supplement for specific health benefits.
- PRINCIPAL PROPOSED USE: High cholesterol
- OTHER PROPOSED USES: Intermittent claudication, Parkinson’s disease, sports performance enhancement
Overview
Policosanol is a mixture of waxy substances generally manufactured from sugarcane. It contains about 60 percent octacosanol and many related chemicals. In some cases, the terms “octacosanol” and “policosanol” are used interchangeably.
Numerous studies have reported that sugarcane policosanol can substantially improve cholesterol profile, with an efficacy approximately equal to that of the most effective drugs used for this purpose. On this basis, policosanol has been approved as a treatment for high cholesterol in about two dozen countries, most of them in Latin America.
However, essentially all positive studies of policosanol were performed and reported by a single Cuban research group, a group with a financial relationship to the product. Independent verification of the product’s effectiveness was delayed for several years by various legal obstacles. Throughout the mid-2020s, several independent studies of sugarcane policosanol were reported. None of these trials have conclusively proven that policosanol lowers cholesterol.
Sources
The tested Cuban policosanol product is manufactured from sugarcane. Octacosanol and related substances are also found in wheat germ oil, vegetable oils, alfalfa, nuts, seeds, beeswax, and various animal products.
Because of political and patent issues, sugarcane policosanol has not been widely available in the United States. Products sold in the American market as policosanol are generally derived from beeswax or wheat germ. These products have a significantly different mixture of constituents and likely have substantially different effects, but they are less well-researched than sugarcane sources. Most experts recommend choosing a supplement derived from sugarcane.
Therapeutic Dosages
Typical dosages of policosanol in Cuban studies have ranged from 5 to 20 milligrams (mg) daily for up to three years. Many supplement manufacturers recommend taking 10 mg daily. In some studies, participants used 40 to 80 mg daily for twenty-four weeks. However, these dosages are not scientifically proven, and a medical professional should always be consulted before taking a new supplement.
Therapeutic Uses
The Cuban research group that holds the patent on sugarcane-derived policosanol has published approximately eighty double-blind studies on its product. If these reports are to be believed, several thousand people with elevated cholesterol levels have been enrolled in clinical trials ranging in length from six weeks to twelve months. In virtually every one of these trials, policosanol proved both more effective than placebo and just as effective as statin drugs.
However, in science, it is always necessary to have independent confirmation of results before a treatment can be considered proven to work. The first truly independent trials of policosanol as a treatment for high cholesterol began to appear in 2006. Of the eighty-nine studies (enrolling more than fifty-seven thousand people) published since then, not one found policosanol more effective than placebo. These results have raised serious doubts about the effectiveness of sugarcane policosanol. In addition, questions are being raised about other scientific claims made by the patent-holding Cuban research group.
Wheat-germ policosanol, sold in the US as a substitute for sugarcane policosanol, failed to prove more effective than placebo in the one published clinical trial of this product. There is no published evidence to indicate that beeswax-derived policosanol affects cholesterol profile. A study published in Croatia reportedly found benefits with rice-source policosanol, but it had significant problems in design and reporting. Considerable doubt exists regarding whether any form of policosanol offers cholesterol-related benefits.
One study, again conducted by the patent-holding Cuban research group, reported that policosanol is helpful for intermittent claudication. Other potential uses of policosanol have been proposed by researchers outside Cuba. A small double-blind trial found marginal evidence that policosanol might enhance sports performance. Marginal benefits were also seen in a small double-blind trial of persons with Parkinson’s disease; however, this study also reported that policosanol can increase the side effects of levodopa, the standard drug used for Parkinson’s disease. Finally, in a small double-blind trial, policosanol failed to produce any benefits in amyotrophic lateral sclerosis.
In 2018, a meta-analysis was conducted on twenty-two studies to determine the overall efficacy of policosanol in lowering blood pressure. Though the results were promising, the majority of the studies used were sponsored or conducted by Cuba’s National Center for Scientific Research, which likely skewed the results.
However, some independent studies report positive impacts from the supplement resulting from its impact on the 3-hydroxy-3-methylglutaryl-coenzyme reductase (HMG-CoA) enzyme. This is similar to the way prescription medications control cholesterol, but policosanol is purported to have less impact on the liver and kidneys than statin drugs. Though this indicates a positive potential for the supplement's use, further human trials are needed.
Safety Issues
Virtually all statements regarding the safety of policosanol derive from studies reported by the patent-holding Cuban research group. Because the reliability of these researchers is in question, all of the following statements are similarly open to question.
Given the above caveat, policosanol is said to be safe at the maximum recommended dose. In double-blind trials, only mild short-term side effects, such as nervousness, headache, diarrhea, and insomnia, have been reported. A safety study of 27,879 people followed for two to four years showed that the use of policosanol produced adverse effects, primarily weight loss, excessive urination, and insomnia, in only 0.31 percent of participants. In animal studies, no toxic signs were seen even at 620 times the maximum recommended dose. In addition, policosanol does not adversely affect the liver. Finally, policosanol does not interact with three types of medications used for high blood pressure: calcium-channel antagonists, diuretics, and beta-blockers.
On the other hand, policosanol may be a blood thinner, and it appears to enhance the blood-thinning effects of aspirin, though one study failed to confirm this adverse effect. Still, to be on the safe side, policosanol should not be combined with aspirin or other blood-thinning drugs, such as warfarin (Coumadin), heparin, clopidogrel (Plavix), ticlopidine (Ticlid), or pentoxifylline (Trental). There is also a remote chance that policosanol might cause excessive bleeding if combined with natural supplements that thin the blood, such as garlic, ginkgo, and high-dose vitamin E. Similarly, persons with clotting problems should avoid policosanol, and the supplement should not be used during the period immediately before or after surgery or labor and delivery. One non-Cuban report suggests that policosanol might increase the action of levodopa, a medication used for Parkinson’s disease, leading to increased side effects called dyskinesias.
The maximum safe dosages for young children, pregnant or nursing women, and persons with severe liver or kidney disease have not been established.
Important Interactions
Persons taking blood-thinning anticoagulants or antiplatelet medications such as aspirin, warfarin, heparin, clopidogrel, ticlopidine, or pentoxifylline should not use policosanol except on medical advice. Also, persons using natural supplements that thin the blood, such as garlic, ginkgo, or high-dose vitamin E, should not use policosanol except under physician supervision. Blood pressure medications and antidiabetes drugs also interact poorly with policosanol. Policosanol may increase both the effects and the side effects of levodopa.
Bibliography
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