Consumer Health Digest #06-44
Your Weekly Update of News and Reviews
October 31, 2006
Consumer Health Digest is a free weekly e-mail newsletter edited by Stephen Barrett, M.D., and cosponsored by NCAHF and Quackwatch. It summarizes scientific reports; legislative developments; enforcement actions; news reports; Web site evaluations; recommended and nonrecommended books; and other information relevant to consumer protection and consumer decision-making.
Vitamin-mineral supplements unlikely to protect against atherosclerosis. A comprehensive review has found no evidence that antioxidant or B-vitamin supplements influence the progression of atherosclerosis as measured with angiography and other imaging techniques. Clinical trials with antioxidants have used vitamins A and C, beta-carotene, and/or selenium. Trials with B-vitamins have used folate, B6, and/or B12. Previous meta-analyses have found that the use of these supplements did not influence the frequency of heart attacks or death. This one was conducted to determine whether there is a protective effect that is obscured by a simultaneous bad effect. [Bleys J and others. Vitamin-mineral supplementation and the progression of atherosclerosis: A meta-analysis of randomized, controlled trials. American Journal of Clinical Nutrition 84:880-887, 2006] An accompanying editorial expressed hope that “the exuberant use of vitamin-mineral supplements may be tempered by such findings, which carefully separate facts from faith.” [McCormick DB. The dubious use of vitamin-mineral supplements in relation to cardiovascular disease. AJCN 84:680-681, 2006]
Policosanol flunks major test. Policosanol, a substance derived from Cuban sugar cane, is widely advertised as effective for cholesterol control. However, a multicenter, double-blind, placebo-controlled study has found that it did no better than a placebo in lowering cholesterol levels in patients with abnormally high levels. Many controlled studies supporting this claim have been published, but the researchers noted that nearly all were supported by a commercial enterprise founded to market policosanol and were performed by a single Cuban research institute. [Berthold HK and others. Effect of policosanol on lipid levels among patients with hypercholesterolemia or combined hyperlipidemia: A randomized controlled trial. JAMA 295:2262-2269, 2006]
Mannatech claims criticized. Major newspapers in Texas have reported that Mannatech distributors are making improper health claims for the company's products. Mannatech is a multilevel marketing company that sells Ambrotose and other glyconutrient products (sugar pills) that it claims "improve cell-to-cell communication." The articles report:
- Three Nobel Prize-winning scientists (Günter Blobel, Paul Greengard, and Paul Nurse) have complained to New York Attorney General Eliot Spitzer that Mannatech distributors improperly cited their research in order to promote Mannatech products. [Robbins D. Nobel Prize winners say sites falsely cite research. Star-Telegram.com, Sept 10, 2006]
- "Third-party literature" containing testimonials has been sold to distributors at Mannatech conferences. [Robbins D. Disputed claims boost popular supplements. Star-Telegram.com, Sept 10, 2006]
- The Texas Attorney General is investigating deceptive claims about effectiveness against cancer and many other ailments. [Hopper L. Pill cure claims draw investigation by state: Mannatech accused of failing to prove sugar pills can remedy various diseases. Houston Chronicle, Oct 28, 2006]
This page was revised on November 2, 2006.