Supplements Headed Downstream?
6 November
2000
by Wyn Snow, Managing Editor
A
noted cardiologist with a decidedly negative bias toward vitamins
and herbs recently remarked that supplement-gobbling Americans have
created a nation with "the most expensive urine in history." Which
raises an interesting question: Are we literally flushing away our
money on dietary supplements? Perhaps, according to at least three
sources.
Dr.
John Potter of Seattle's Fred Hutchinson Cancer Research Center,
observes that 190 solid studies prove the cancer-fighting benefits
of eating lots of fruits and vegetables, but "supplements have only
a smattering of evidence" supporting their ability to fight cancer
-- (Reported by AOL news on 4 September 2000).
Dr.
Stephen Barrett, author of the Quackwatch website, says, "A few
[dietary supplements, herbs and hormones] are useful, but most are
promoted with false or misleading claims."
And
concerning the recent trend of adding herbal supplements to foods
(so-called functional foods), "Food companies are . . .
misleading consumers about their health benefits," according to
Bruce Silverglade, director of legal affairs for the Center for
Science in the Public Interest (CSPI). "It's shameful that respected
companies are selling modern-day snake oil."
Are
Americans then behaving foolishly by spending upwards of $15 billion
annually on dietary supplements? More and better designed research
is needed to answer this question fully -- although some results
are available now.
IBIDS database bursting with research
The
International Bibliographic Information on Dietary Supplements (IBIDS)
Database recently completed its sixth quarterly update -- and now
has upwards of 400,000 unique bibliographic records about dietary
supplements from 1986 to the present. IBIDS is a searchable database
of published, international, scientific literature on dietary supplements,
including vitamins, minerals, herbs and botanicals.
Critics
of international research characterize much of it as flawed in various
ways -- but solid, reliable, well-designed, peer-reviewed evidence
about the health benefits of many supplements is growing. Links
to several research databases
are available in the links section of our website. And news about
various new studies -- some of it quite positive -- appears regularly
in the media. Two typical examples focus on antioxidants and the
popular joint supplements glucosamine and chondroitin.
Vitamins plus antioxidants improve heart disease mortality rates
Taking
a multivitamin together with an antioxidant (vitamin A, C
or E) appears to reduce one's risk of dying from heart disease or
stroke by approximately 15% -- according to a study reported in
the July issue of the American Journal of Epidemiology
that followed 1 million Americans aged 30 and older for 7 years.
However, people who took only a multivitamin did not fare better
than those who took no vitamins at all -- and the study showed no
differences in cancer death rates between those who took supplements
and those who did not.
Glucosamine and chondroitin ease osteoarthritis pain
Five
million Americans now use glucosamine and chondroitin sulfate, partly
because of their effectiveness in animals and partly because of
the best-selling book, The Arthritis Cure -- according
to an article published in The Boston Globe on 25
September 2000.
Dr.
Timothy McAlindon of Boston University examined the European research
on these supplements (more than three dozen studies) and concludes
they are safe and do reduce osteoarthritis pain, according to his
report published earlier this year in the Journal of the American
Medical Association. McAlindon says, "At the moment the
evidence is favoring these products,'' but added that most of the
European research was sponsored by supplement manufacturers and
"was not that well done. They seem to exaggerate the treatments'
efficacy."
To
address these concerns, the effectiveness of glucosamine and chondroitin
will soon be addressed in NIH-funded research studies. A $10 million
project with 1,500 patients will look at whether these two supplements
reduce arthritis pain, and whether they impact the disease itself.
According to Dr. Robert Karpman in Phoenix, AZ, "It seems to slow
the arthritic process, but it doesn't repair the joint surface.''
Profit-making organizations often do flawed research
Supplement
producers are not the only authors of flawed research -- according
to an article published in The Lancet in August 2000
and reported in AOL News on 17 August 2000.
"A
clinical trial should only be carried out if there is substantial
uncertainty about which one of two treatments is more effective,"
according to Benjamin Djulbegovic of the H. Lee Moffitt Cancer Center
and Research Institute at the University of South Florida. But in
136 trials of treatments for a specific blood disease, Djulbegovic
and his colleagues found that trials "funded partly or only by profit
making organizations" showed a strong tendency to prefer the experimental
treatment over older methods (74% versus 26%), while trials "supported
by governments and non-profit organizations" were more balanced
(47% versus 53%).
The
profit-making organizations were more likely to use inferior controls,
thereby creating a bias favoring the new treatment. According to
Djulbegovic, "Profit-sponsored research used inferior controls in
60 percent of cases while trials funded by non-profit organizations
only used inferior controls in 21 percent of cases."
Independent research on the rise
Such
flaws are an excellent argument in favor of independent, basic research
performed by academicians. The National Institute of Health (NIH)
is now funding four research centers focusing on botanical supplements
through the Office of Dietary Supplements (ODS) and the National
Center for Complementary and Alternative Medicine (NCCAM).
Each center receives approximately $1.5 million per year for five
years. These four research centers are:
-
The UCLA Center for Dietary Supplements Research on Botanicals,
directed by Dr. David Heber, is researching yeast fermented
rice, green tea extract, soy isolates, St. John's wort, and
levels of bioactive compounds in several botanicals.
-
The University of Illinois at Chicago, directed by Dr.
Norman Farnsworth, has established a Dietary Supplements
Research Center focusing on ten herbal supplements that
may benefit women's health issues, including menopause.
-
The Purdue Center for Dietary Supplement Research on Botanicals
(at Purdue University), directed by Connie Weaver, PhD, will
study the health effects of polyphenols (a diverse group of
chemical components widely distributed in plants) -- many of
which are consumed both for their nutritive value and medicinal
properties. Examples include soy, grapes, green tea, and several
herbs.
The Purdue Center's proposed research is important for heart
disease, cancer, osteoporosis, and cognitive decline. Purdue
researchers will collaborate closely with investigators at the
University of Alabama at Birmingham (UAB), directed by Stephen
Barnes, PhD.
-
The University of Arizona Center at Tucson, directed
by Barbara Timmermann, PhD, will focus on three botanicals (ginger,
turmeric, and boswellia) widely used in Ayurvedic medicine for
the treatment of inflammatory diseases. The researchers propose
to identify the active constituents of these three herbs and
study their pharmacological activity.
Supplements and drugs: Apples and oranges?
With
new US-based supplement research expanding rapidly, a few often
overlooked facts about supplements are worth noting. For instance,
many of the active ingredients in supplements, when synthesized
and refined, are the basis for well studied and proven over-the-counter
remedies as well as prescription drugs.
Similarly,
recent studies of St. John's wort were reported on in The
Boston Globe, but with a critical focus on variations in
standard dosage and uniformity of product quality. Almost without
comment, Globe coverage noted that St. John's wort contains
naturally occurring reuptake inhibitors of seratonin and dopamine,
in amounts comparable to the primary psychoactive ingredient in
Prozac, enough so that patients with moderate levels of depression
taking the supplement would receive useful amounts without having
to resort to the much more expensive drug.
For
those wondering whether supplement users are flushing away money
that might better be directed elsewhere, the jury is not only still
out, it has yet to be really convened. A gathering volume of research
is pointing toward positive results, and clinical studies done under
federal sponsorship will also bear careful analysis.
In
the meantime, consultation with knowledgeable care givers and an
eye to verifiable supplement quality are still the best way to avoid
being swept downstream on a tide of cynicism and misplaced contempt.
Sources:
"Nutrition
Industry Sales Reach $44.5 Billion." Nutrition Business Journal
press release, 5 October 2000.
Stephen
Barrett, MD. "`Dietary Supplements,' Herbs, and Hormones." Quackwatch.com,
www.quackwatch.org/01QuackeryRelatedTopics/DSH/suppsherbs.html,
(updated most recently 9 October 2000).
Center
for Science in the Public Interest. "FDA Urged to Halt Sale of `Functional
Foods' Containing Illegal Ingredients." Press release, www.cspinet.org/new/fda_functfoods.html,
18 July 2000.
Lauran
Neergaard. "Dietary Supplements No Substitute" [for Food]. The Associated
Press, AOL news, 4 September 2000.
Reuters.
"Clinical trials break basic scientific rules." AOL news,
17 August 2000. (Reporting on Benjamin Djulbegovic et al. "The uncertainty
principle and industry-sponsored research." The Lancet,
August 2000, Vol. 356, Issue 9230, page 635.)
Reuters
Health Information. "Vitamins Reduce Risk of Death From Heart Disease,
Stroke." Vitacost.com news, www.vitacost.com/whatnew/news/aug2000/news08vit.html
(Reporting on article in American Journal of Epidemiology,
July 2000;152:149-162.)
Larry
Tye. "Boom for joint drug prods scientific study." The Boston
Globe, 25 September 2000.
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