Scientist says flax can provide Omega-3 needed in diet

TORONTO – Bruce McDonald, professor of food and nutrition at the University of Manitoba in Winnipeg, has let modern science lead him back to an old way of doing things.

After delving into the nutritional traits of flax, he’s convinced that some health food advocates had the right idea years ago. At a presentation here recently, McDonald recalled an incident years ago when he debated a health food advocate about the merits of flax.

“Now I’m putting it (flax) on my granola. That’s what he was doing 30 years ago,” he said.
North American flax production has been geared to make paint, paper and linen, but science now shows blue flax fields are a nutritional treasure trove of lignans, fatty acids and fibre.

Lignans, biologically active chemicals manufactured by certain plants, appear to have anti-cancer properties.

“The reason we started working with flax is that it by far has the highest concentration of lignans of any of the vegetable and plant products out there,” McDonald said. “It’s eight to 10-fold higher than the next best source.”

In laboratory tests with induced breast and colon cancer, lignans helped prevent the early stages of cancer and were shown to be effective in fighting the disease in its later stages.

As well, people who eat a diet high in fruits and vegetables tend to have lower incidences of heart attacks, McDonald said.

Flax oil prospects have been heightened by recent studies that show ingesting foods with unsaturated fats to reduce cholesterol buildup is not enough. Eating different kinds of unsaturated fats with different fatty acids in the correct proportion is important as well.

“The popular thing out there was that unsaturated fats prevent cholesterol from building up,” McDonald said. “We went to more unsaturated fats in our diet as a consequence of the concern with saturated fats.”

Flax oil contains large amounts of a fatty acid called alpha linolenic acid. This is an omega-3 acid, an essential nutrient not common in the usual Canadian diet.

The typical North American diet contains a ratio of omega-6 to omega-3 from10:1 to as high as 25:1. Health Canada recommends a ratio of 4:1.

Dietary fibre is another factor. Flax seed is 23 percent fibre by weight of which a third is soluble. Fibre absorbs water in the intestine and increases intestinal bulk. This provides what McDonald delicately referred to as laxation.

This article appeared in
The Western Producer
June 25, 1998

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