Herbal products contain fillers, contaminants, omit ingredients on labels: study

Do you know what's in your daily vitamin? A new study says, probably not. Christopher Furlong/Getty Images

TORONTO – Canadians are becoming more and more conscious of the ingredients on their plate, in household cleaning products, cosmetics and beauty.

But for all their trying, a new study shows that when buying natural health products – things like vitamins, minerals and herbal remedies – many don’t know what ingredients a product contains.

Researchers from the University of Guelph tested 44 herbal products from 12 companies, all of which are available to consumers in Canada and the USA.

They found that the majority of the products, 60 per cent, contained ingredients not listed on the label. Moreover, most companies substitute high quality herbal ingredients for cheaper ingredients, contaminants and fillers.

Contamination poses serious health risks to consumers

“Contamination and substitution in herbal products present considerable health risks for consumers,” said Steven Newmaster, lead author and integrative biology professor at the University of Guelph.

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In one case, a product labelled as St. John’s wort was substituted with senna, a herbal laxative that is not meant for prolonged use as it can cause chronic diarrhea and liver damage among other things.

A number of other products were contaminated with feverfew. Although feverfew has been used traditionally to treat migraines and arthritis, it has side effects including oral ulcers, nausea and vomiting, and reacts with other medications. Pregnant women should not consume any amount of feverfew.

Fillers used in products – but not listed on the label – included rice, soybeans and wheat, a concern for those with allergies or who are trying to use only gluten-free products Newmaster said.

He said that while the use of fillers is standard practice with herbal and natural products, consumers have a right to know what’s in the products they’re using.

Of all the companies tested, researchers said only two had authentic herbal products, free from contaminants, fillers and substitutes.

Regulation of natural health products

The herbal product industry is a big black box. There are no standards for the authentication of herbal products, and the industry suffers from fraud and unethical practices by some manufacturers, said Newmaster.

“As a result, the marketplace is prone to contamination and possible product substitution, which dilute the effectiveness of otherwise useful remedies, lowering the perceived value of all related products because of a lack of consumer confidence in them.”

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Medicinal herbs are the fastest-growing segment of the alternative medicines market in North American, said the researchers. It’s a $60-billion a year industry, with thousands of companies operating around the world.

“There is a need to protect consumers from the economic and health risks associated with herbal product fraud,” said Newmaster.

While Canada has regulated natural health products since 2004, Newmaster said there is a massive backlog of licence applications. Thousands of products in the stores right now don’t have a full product licence. A 2010 poll showed that while three out of every four Canadians use natural health products, the majority (79 per cent) do not look on the label for a Natural Health Product License Number (NPN) or Drug Identification Number for Homeopathic Remedies (DIN-HM) on the product.

He said that regulatory problems around the world continue to affect the safety and consistency of natural health products.

Up until this point, determining what was inside herbal pills was difficult, so his team developed standard methods and tests using something called DNA barcoding, which uses biotechnology to quickly and accurately identify plant material based on standardized gene sequences.

Newmaster hopes that the herbal industry adopt DNA barcoding in order to authenticate herbal products going to market.

The study was published Friday in the journal BMC Medicine.


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