When I recently wrote about glucosamine, I discussed the evidence up through the New England Journal of Medicine study of 2006, which I thought was a pretty definitive study showing that neither glucosamine, chondroitin or a combination of the two was more effective than placebo. Subsequent studies have continued to fuel the controversy. One 2007 study showed that glucosamine sulfate was better than placebo for knee osteoarthritis. Another 2007 study showed that glucosamine HCl and chondroitin, with or without exercise, were no better than placebo for knee osteoarthritis. Sources like the Natural Medicines Comprehensive Database believe the evidence favors glucosamine sulfate but not glucosamine hydrochloride.
A new study was published 19 February 2008 in the prestigious Annals of Internal Medicine. It is arguably the best study to date, and may shed some light on the controversy. Carried out in the Netherlands in a primary care setting, it studied 222 patients with hip osteoarthritis over a 2 year period. Half the patients took glucosamine sulfate 1500 mg a day; half took a placebo. They concluded that glucosamine sulfate was no better than placebo in reducing symptoms and progression of hip osteoarthritis. (more…)
The core principle of science-based medicine is that health care decisions should be based upon our best current scientific evidence and understanding. When applied to the regulation of health products this means that health claims should first be required to meet some reasonable threshold of scientific evidence before they are allowed. Admittedly this is not a purely scientific question but the application of scientific knowledge to an essentially political question – the balance of protection vs freedom.
Regardless of where one thinks this balance should be, I think most would agree that is it a problem if the public generally wants more protection than it is getting, or believes it is currently getting more protection than it is. A Harris poll from 2002 indicates that the majority of Americans believe that companies cannot make health claims about supplements unless they have been proven scientifically and approved by the FDA, when in fact this is not the case. The Dietary Supplement Health and Education Act of 1994 (DSHEA), largely through the efforts of Senator Orin Hatch from Utah, removed supplements from the control of the FDA and specifically allowed for so-called structure function claims to be made about products without any burden of proof. Most Americans are not aware of this fact.
A new study by lead author Shelly Gray and published in the latest issue of the Journal for the American Geriatric Society, found no effect from taking Vitamin C or E, either alone or in combination, on the risk of dementia or Alzheimer’s disease after 5.5 years. Vitamins C and E were chosen because they both have significant antioxidant activity, and so this study was partly to test the hypothesis that oxidative stress causes or contributes to dementia.
The science behind the role of oxidative stress in aging and neurodegenerative disorders and the modulation of oxidative stress by nutritional antioxidants is complex and has not yielded many confident therapeutic recommendations. And yet, by contrast, antioxidants are sold to the public with dramatic health claims as if they were well established. It is common for marketing hype to out pace scientific reality, especially when the science is complex and preliminary so that there is as yet no firm scientific consensus.
For background, oxidative stress refers to the production in the cells of the body of certain oxygen-based compounds, collectively called reactive oxygen species (ROS), that are highly reactive. Some of these compounds are simply waste products of cell metabolism. Others serve a useful purpose, such as nitric oxide that is used in neurotransmission. What these ROS compounds have in common is that they react with proteins, DNA, and other cell components and cause damage.
Glucosamine and chondroitin, used separately or together, are among the more popular diet supplements. They are used widely for osteoarthritis, especially of the knee, and have been better studied than most other diet supplements. But do they really work?
The journal of my medical specialty, American Family Physician, recently published an article about the use of dietary supplements in osteoarthritis. They gave a “B” evidence rating to both glucosamine and chondroitin. This means there is inconsistent or limited-quality patient-oriented evidence. They recommended the use of glucosamine sulfate, saying, “Overall, the evidence supports the use of glucosamine sulfate for modestly reducing osteoarthritis symptoms and possibly slowing disease progression.” They did not exactly recommend chondroitin, although they said it “may provide modest benefit for some patients.”
I remain skeptical. And so does R. Barker Bausell, who devoted several pages of his book Snake Oil Science to an analysis of the research on glucosamine and chondroitin. (more…)
Over the last few months, I have had a truly surreal experience. It started when I noticed a two-page full color spread in TV Guide magazine advertising a product called Akavar 20/50. It contained the same claims that so many bogus weight loss products do: eat all you want and still lose weight. What attracted my interest was their highlighted statement: “We couldn’t say it in print if it wasn’t true!”
I laughed out loud. Anyone can say anything in print until they get caught. These diet ads all say things that aren’t true, and the FTC can’t begin to catch them all.
The ad describes research results they call “staggering.” They have scientific documentation that 23 out of 24 patients using Akavar’s active ingredient lost weight. They also described a controlled, randomized clinical trial of their actual product in which 23 out of 24 patients lost “a substantial amount of weight.” Two questions immediately came to mind: why were the numbers the same in both studies, and if a single active ingredient worked just as well, why was there any need to develop the Akavar formulation?
There was a toll-free number where I could call for further information. I called and asked for the citations of the two studies they referred to. The man who answered was flummoxed: “No one’s ever asked me that before.” He had to go for help. Finally he came up with the names of two journals and no further information.
I searched PubMed for anything in either of those journals that might even remotely be the studies they described, and I couldn’t find anything. I wrote the company’s customer service representative and asked for more information. And then the real fun began. Here are the actual e-mails for your delectation: (more…)
A recent web feature produced by the New York Times tells the story of Chris Kilham, “The Medicine Hunter.” Specifically it recounts his thoughts on the use of maca, a root native to South America, “said to have energy and libido enhancing properties,” according to the piece. The brief piece reflects the current attitudes popular in the public and promoted by mainstream media reflecting a false dichotomy between medicinal plants and pharmaceuticals. This false dichotomy is extremely counterproductive and ultimately harmful to consumers.
Kilham represents this false dichotomy when he says:
“My goal is to have more people using safe, effective, proven, healthful herbs, and fewer people using toxic, overly expensive, marginally effective, potentially lethal pharmaceutical drugs.”
There are many unwarranted assumptions in this statement. It seems to be implying that herbs are inherently more safe, less toxic, and more healthful than pharmaceuticals. It also assumes that there is a real difference between the two. Therefore Kilham seems to be saying something meaningful when he is actually just reflecting biased assumptions. This is made clear if we simply reverse his statement. Most people, for example, would agree if I said that “My goal is to have more people using safe, effective, proven, healthful pharmaceuticals, and fewer people using toxic, overly expensive, marginally effective, potentially lethal herbs.”