Winnipeg-based clinical trial has wowed cardiac specialists with its blood-pressure reducing results


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Cardiac specialists around the world are paying close attention to a potentially groundbreaking Winnipeg-based clinical trial that shows flaxseed lowers blood pressure in patients with heart disease--more than any dietary measure ever demonstrated in science.

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Hey there, time traveller!
This article was published 03/12/2012 (3708 days ago), so information in it may no longer be current.

Cardiac specialists around the world are paying close attention to a potentially groundbreaking Winnipeg-based clinical trial that shows flaxseed lowers blood pressure in patients with heart disease–more than any dietary measure ever demonstrated in science.

The drop in blood pressure equals a 50 per cent drop in stroke risk and a 30 per cent drop in heart attack risk, says the study’s lead investigator, Grant Pierce.

In November, the American Heart Association (AHA) allowed Pierce and his colleagues to present their research at the AHA conference in Los Angeles, attended by more than 20,000 cardiac physicians and researchers from more than 100 countries.

CP Blood pressure was a secondary measurement in the St. Boniface study, but it took on a greater significance as the results were recorded.

“(Reaction) varied from, ‘Wow. I can’t believe this.’ To lots of questions. To lots of congratulations,” says Pierce, a U of M physiology professor who is also St. Boniface General Hospital’s executive director of research.

The American Heart Association even features news of the joint St. Boniface Hospital/University of Manitoba (U of M) flax study on its website,

“We’re excited because the trial itself was done in a very tightly-controlled manner, which means we have very good confidence that the results were real,” says Pierce, who is confident his research will be published in a respected, peer-reviewed scientific journal in the upcoming months.

He says the elaborate, year-long, double-blind, randomized, placebo-controlled trial cost nearly $1 million, funded by Flax 2015, Canada Bread, the Canola Council of Canada, the Agriculture Research Development Initiative, Glanbia Nutritionals Inc., the Canadian Institutes of Health Research and St. Boniface Hospital Foundation.

In the study, 110 people were randomly divided into two groups. One group ate a grain product (either a bagel, bar, muffin or pasta) daily containing 30 grams (about three heaping tablespoons) of milled flaxseed. Meanwhile, the other group ate a placebo — a grain product that looked and tasted like the flaxseed version, but didn’t actually contain any flax.

During the trial, neither the subjects nor the researchers knew who was in the placebo group or who was in the flax group.

Nearly 80 per cent of the participants went into the trial with elevated blood pressure, peripheral arterial disease (PAD) and on medication to lower their blood pressure. (PAD is an often detrimental circulatory problem in which constricted arteries reduce blood flow to the legs and arms).

So far, the researchers have analyzed the first six months of the study. The data shows the flaxseed group lowered their systolic blood pressure by an average of 15 millimetres of mercury (mmHg) while they lowered their diastolic blood pressure by an average of seven mmHg.

Trial participants with normal blood pressure did not experience a significant drop in blood pressure after ingesting daily flax.

Systolic blood pressure is the pressure on your arteries as your heart beats–the top number of a blood pressure reading. Diastolic blood pressure is the pressure on your arteries in between beats–the bottom number of a blood pressure reading.

“You might not think it is unless you’re in the hypertensive area, but every little millimetre makes a big difference in heart attacks and strokes,” says Pierce, reiterating that the drop is enough to cut stroke risk in half and lower heart attack risk by 30 per cent.

In the placebo group, systolic blood pressure increased marginally while diastolic blood pressure stayed stable. The flaxseed group experienced significant increases in their levels of heart-healthy omega 3 fat, alpha linolenic acid as well as a 10-fold increase in the potent antioxidant enterolactone. The placebo group did not experience such changes.

Pierce says subjects in the flax study had an even greater drop in blood pressure than seen in the respected DASH (Dietary Approaches to Stop Hypertension) trial. That study put subjects on the widely-accepted DASH Diet, a low-fat regimen that emphasizes whole grains, produce and portion control.

Are these the results Pierce expected?

“Absolutely not. We were concentrating on, for example, cholesterol. We were thinking there would be other changes, for example, in arrhythmias. Blood pressure was a secondary measurement for us.”

Pierce says the study could have far-reaching health implications since high blood pressure is a growing problem that affects 50 million Americans and five million Canadians.

It could also have an economic impact in Canada since we are the world’s largest flax producer and exporter on the planet, according to the Flax Council of Canada.

“The stars are aligned nicely here,” says Pierce, who hopes his study could drive up flax demand. He also hopes that developing countries can use the relatively inexpensive and easily-eaten crop to boost health.

PHIL HOSSACK / winnipeg free press Grant Pierce poses with a beaker of flaxseed at the St Boniface Reasearch Centre where he and associates have been studying the effects of flax on heart patients.

What makes flax, a nutty-tasting seed, so work so well?

Pierce says its ingredients, in isolation, have all been shown to lower blood pressure in small amounts. “What I think is happening is we have a superfood that is having a synergistic effect on blood pressure.”

He says he’s not sure whether the flax in this study acted alone in lowering patients’ blood pressure or whether it boosted patients’ antihypertensive medication.

He says he will look into that in a future clinical trial.

Judging by the comments on the AHA website, those interested displayed a cautious optimism at the study.

“Impressive but only 110 patients. clearly need verification in a larger group. I would not want to change practice based on 50 people taking a treatment!!!,” says one web heckler, presumably a physician.

Says another web commenter: “Sad to say many patients think ‘newest, most expensive, most innovative’ is the best! How many other ‘simple’ alternatives are really good or better, but we have no proof because there is no money to be made in finding out??”


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The flax facts

The research: A year-long, million-dollar clinical trial that found flax seed lowered blood pressure more than any other dietary intervention ever seen in a study.

What it means to your health: Daily ingestion of flax could cut stroke risk in half and lower heart attack risk by 30 per cent.

Who thinks it’s a big deal: The American Heart Association, who featured the study at it’s recent conference in Los Angeles.

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