In the last decade the National Institutes of Health has devoted over $2 billion to studying complementary and alternative medicine. This has included several major clinical trials on herbs, vitamins, and supplements. When supplement research results report harm, the published studies appear to be more influential to consumers and their physicians than results reporting lack of efficacy. When you take any supplement it should be based on both safety and whether or not it works (efficacy).
This is especially true when we look at Vitamin E. Vitamin E is typically purchased and consumed as a preventative supplement. Vitamin E is a fat-soluble anti-oxidant that was thought to reduce oxidative stress linked to cancer and heart disease. It was also the most common supplement recommended by physicians. In 2005 the results were published from a major vitamin E trial that showed participants who took >800 IU of Vitamin E per day had higher mortality (death) rates. Later in 2005 data from two additional studies reported little or no effect of vitamin E in preventing cancer and cardiovascular disease. Sales of vitamin E decreased by 33 % the following year. Investigators feel that when supplement research results report harm, the results influence consumers and their physicians more so than results reporting a lack of benefits or efficacy.
Glucosamine and Chondroitin
These supplements gained popularity for the symptoms of osteoarthritis. This supplement is not purchased as a preventative but rather to address acute and chronic symptoms associated with stiffness and joint pain common to arthritis. In 2006 the results were published from two federally funded studies. In these studies there were no serious adverse events. However the results showed that glucosamine alone and in combination with chondroitin did not improve the symptoms of osteoarthritis more than a placebo. In a secondary analysis the glucosamine/chondroitin combination was more beneficial than the placebo in a subgroup of participants with moderate-to-severe osteoarthritis symptoms. No physical harm has been associated with glucosamine and chondroitin. Consumer use of these supplements has not decreased despite the reported decrease in actual benefits. Consumers might be better to consider supplements containing curcumin (pharmaceutical Turmeric) for inflammation and the symptoms of osteoarthritis and rheumatoid arthritis pain.
The berries or fruit from saw palmetto is used to treat urinary symptoms related to benign prostatic hyperplasia (BPH) or an enlarged prostate. This supplement is purchased for the chronic symptoms associated with an enlarged prostate. In 2006 the results of a large study was published in the New England Journal of Medicine which showed that while saw palmetto was well tolerated, it was no better than placebo in improving the symptoms of BPH or an enlarged prostate in the study participants. Uniquely saw palmetto does contain beta-sitosterol which does show statistically significant benefits in clinical studies in improving the symptoms of an enlarged prostate. The big difference is that it would take about 200 capsules of saw palmetto to equal one capsule with 300 mg of beta-sitosterol. The efficacy of beta-sitosterol when studied with enlarged prostate symptoms has been published in the British Journal of Urology, the Lancet, and the Cochrane Database of Systematic Reviews. Despite the study results of saw palmetto annual sales of saw palmetto in the US exceed $135 million annually. Again consumers are better off choosing a natural prostate supplement that uses the ingredient beta-sitosterol.
The following resources are credited for the article above:
- Tilburt JC, Emanuel EJ, Miller FG. Does the evidence make a difference in consumer behavior? Sales of supplements before and after publication of negative research results. J Gen Intern Med. 2008;23:1495–1498.
- Wilt T, Ishani A, MacDonald R, Stark G, Mulrow C, Lau J. Beta-sitosterols for benign prostatic hyperplasia. Cochrane Database Syst Rev . 2000:CD001043.
- Klippel KF, Hiltl DM, Schipp B. A multicentric, placebo-controlled, double-blind clinical trial of beta-sitosterol (phytosterol) for the treatment of benign prostatic hyperplasia. Br J Urol 1997;80:427-32.
- Berges R.R., Windeler J., Trampisch H.J., et al. Randomised, placebo-controlled, double-blind clinical trial of beta-sitosterol in patients with benign prostatic hyperplasia. Lancet; 345:1529–32, 1995
- Miller ER 3rd, Pastor Rriuso R, Dalal D, et al. Meta-analysis: high dose vitamin E supplementation may increase all-cause mortality. Ann Intern Med. 2005;142:37–46.
- Clegg D, et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. New Eng J Med. 2006;354:795–808.
- Bent S, Kane C, Shinohara K, et al. Saw palmetto for benign prostatic hyperplasia. N Eng J Med. 2006;354:557–66.