Studies draw attention to nutraceuticals at Canadian medical conference

By Clarisse Douaud

- Last updated on GMT

Related tags Natural health products Alternative medicine Medicine

Studies presented at the North American Research Conference on
Complementary and Integrative Medicine point to the medical
establishment's growing interest in alternative therapies -
counterbalancing recent denouncements against the field.

Natural health products and functional foods played an important role at the Edmonton, Canada conference whose primary host was a group of 32 medical schools called the Academic Consortium for Complementary and Alternative Health Care.

Fours studies pertinent to the herbal and dietary supplement and functional foods industry included: pharmacists' attitudes to natural health products, the potential deterioration of probiotic supplements before they reach shelves, herb-drug interaction in patients with osteoperosis and green tea as an aid for immunity disorders.

The public is the motivation behind the conference and not the medical establishment itself, according to one of the organizers of the conference.

"Our work is to serve the public interest, and the public has overwhelmingly indicated they want to know more about the safety and efficacy of these therapies,"​ Dr. Sunita Vohra of the University of Alberta told, "the use of natural health products is extremely common in adults and children, hence it is important to collect data on which therapies 'work' for which conditions, and which do not."

Last week a letter was sent by senior doctors in the UK to health care trusts urging that funds be spent only on evidence-based medicines. The communiqué sparked furious debate about the role of complementary and alternative medicines. Prince Charles' Foundation for Integrated Health struck back saying that alternative medicine should have a more prominent place in health care.

Dr. Vohra says that on one end of the spectrum of opinion surrounding complementary and alternative therapies there are those who don't need evidence because they say this body of work is "bunk". At the other end, she says, are people who don't need evidence because they accept the therapies' value without question.

"This conference and its broad appeal is to the larger group in the middle, who try to have an open mind, but who remain uncertain or skeptical, and for whom evidence will guide their opinion as to what works and what doesn't,"​ said Dr. Vohra.

In the case of the conference, what works and what doesn't was very much linked to adverse events reporting and product safety.

One study presented suggested many pharmacists are encountering reportable adverse events in patients using natural health products, but are not reporting these events.

In the survey, 47 percent of 132 pharmacists indicated they had seen a potential natural health product-drug interaction or adverse event. But out of these only 2 respondents reported the interaction to Health Canada and about half discussed it with the patient.

A second study, conducted as part of the Canadian multicenter osteoporosis study, found few potential drug-herb interactions in patients with osteoporosis.

The patients were divided between those taking cardiovascular agents and those taking neuroleptic agents. Researchers assessed whether or not herbal therapies, such as St.John's Wort, patients were taking were adversely interacting with these drugs.

"In this randomly selected, population-based sample we found a relatively low rate of potential drug-herb interactions, most of which were among subjects using specific cardiovascular medications,"​ the authors concluded.

Of the 514 subjects on one of the cardiovascular medications, 2.5 percent were using a contraindicated herb. Only one of the 514 subjects taking a neuroleptic agent was identified as at-risk for a potential drug-herb interaction (lithium and psyllium).

The third relevant study presented at the conference looked at quality assurance and lactobacillus-containing dietary supplements commercially available in Washington State.

The authors showed that while probiotic supplements contain so-called 'friendly' bacteria, they also contain live microorganisms that make them susceptible to contamination and loss of effectiveness during shipping and storage.

The investigators concluded most Lactobacillus supplement products in Washington State were viable, but found a large discrepancy existed between labeling and actual contents. The most commonly identified labeling discrepancy was at the species level rather than the genus level.

"Many products contained organisms not listed on the label,"​ the authors noted. "Some of these could act as human pathogens, posing risk if used by susceptible consumers,"​ they added. It is not clear where quality was compromised in the chain of events from manufacturer to consumer.

Of the 94 samples analyzed, investigators found 88 percent were viable. Of these, manufacturer labeling exactly matched only 8 percent of the products, while 51 percent contained at least one organism that matched labeling at both genus and species level.

Disturbingly, seventy-one percent of the supplements contained at least one organism not listed on the label, and ten percent had more than one potentially pathogenic organism.

The only ingredient-based study presented at the conference was done on green tea - and its potential to help with impaired immunity, namely HIV infection.

The study claims to have shown that the green tea component epigallocatechin gallate (EGCG) binds to the CD4 molecule on immune cells, inhibiting HIV from attaching to host cells.

"We have demonstrated clear evidence of high affinity binding of EGCG to the CD4 molecule. EGCG at concentrations equivalent to those obtainable by the consumption of green tea is able to significantly reduce the attachment of gp120 to CD4,"​ the authors concluded.

While EGCG may be effective against HIV in laboratory cells, much more research is needed to determine if it has potential in infected humans, say the authors.

Among the 16 participating organizations at last week's conference were the American Academy of Pediatrics, the International Society for Complementary Medicine Research and the Advanced Food Materials Network, as well as medical researchers representing various North American university hospitals.

"We had 650 registrants from 23 countries, signifying the relevance and importance of this topic to scientists from around the world,"​ said Dr.Vohra.

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