Flaxseed proponents will admit other forms of omega-3 fatty acids have more scientific studies to back health claims than alpha-linolenic acid (ALA), the form of omega-3 fatty acid found in flaxseed.
"Most of the work in omega-3 oil obviously has been done on EPA and DHA," said Kelley Fitzpatrick, director of health and nutrition for the Flax Council of Canada, Winnipeg, Man. "The flax industry has mostly focused on the study of milled flax."
Ms. Fitzpatrick, who also is a technical adviser for Glanbia Nutritionals, Inc., Monroe, Wis., added, "I would certainly concur we need way more research on ALA on its own."
The Flax Council of Canada is working on that. The group has joined forces with the Canola Council of Canada, Winnipeg, for a clinical trial that will look at the effects of ALA, EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid) on cardiovascular benefits, Ms. Fitzpatrick said. Oils sourced from canola, flaxseed and fish will be tested. The project, which is in the funding application process, may cost $2.5 million over three years, Ms. Fitzpatrick said.
A recent review performed at the University of Guelph in Ontario examined studies involving all three kinds of omega-3 fatty acids: plant-based ALA and EPA and DHA from fish oil. Titled "Are all n-3 polyunsaturated fatty acids created equal?" it was published on-line Aug. 10 in Lipids in Health and Disease. It reviewed dozens of studies examining the effects of omega-3 polyunsaturated fatty acids on chronic diseases, including cancer, insulin resistance and cardiovascular disease.
"Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in particular have been studied extensively, whereas substantive evidence for a biological role for the precursor, alpha-linolenic acid (ALA), is lacking," the researchers said.
More work is needed to identify the effects of ALA on the diseases, the researchers concluded.
"The need is evermore apparent, given that ALA is by far the predominant form of n-3 PUFA (omega-3 polyunsaturated fatty acid) consumed in the typical North American diet and its conversion to EPA and DHA is minimal," the authors said.
The body converts ALA into EPA and DHA, but debate has arisen over how much it converts. The percentage has been reported as low as in the single digits.
Maybe researchers are looking in the wrong places for conversion of ALA into EPA and DHA, said Dan Best, founder and president of Best Vantage, Inc., based in Northbrook, Ill., and involved in food business and technology marketing. The company has done work for Enreco, Inc., Sheboygan Falls, Wis., a supplier of flaxseed ingredients.
Mr. Best pointed to two published scientific studies to back up the conversion opinion. An article published in 2002 in the Journal of Lipid Research involved piglets. It showed conversion of ALA into DHA occurs in the tissues and would not be reflected in the blood plasma.
"Blood plasma is how conversion of ALA to DHA has historically been measured, but in our view this is false, as the conversion of ALA to DHA does not show up in the blood there," Mr. Best said.
Another article appearing in 2006 in The Journal of Nutrition examined how the act of conversion occurred in the target tissues in canines and thus would not show up in the blood stream.
All three forms of omega-3 fatty acids are beneficial, Ms. Fitzpatrick said.
"We’ve got to get away from either-or, either ALA or fish oils," she said. "It’s both. It has to be both. You cannot say one or the other. You cannot fortify enough foods with just fish oil to meet omega-3 needs."
Pizzey’s Nutritionals, based in Angusville, Man., and part of Glanbia P.L.C., offers an ingredient that combines all three forms of omega-3 fatty acids. Fish oil naturally is encapsulated in milled flaxseed in MeadowPure UltraGrad.
Customers of Pizzey’s Nutritionals may custom-formulate how much EPA, DHA or ALA is in their ingredients. For example, companies wanting a finished product that benefits mental development of children may want more DHA in the ingredient, Ms. Fitzpatrick said. Companies wanting a product focused on heart health may want more EPA.
Flaxseed oil is about 57% ALA, according to the Flax Council of Canada, while flaxseed itself contains 23% ALA by weight. Only 1.6 grams of whole-milled flaxseed per U.S. Department of Agriculture reference serving contributes enough flaxseed to make an "excellent," "rich" or "high" source claim for omega-3 fatty acids on a food product label, Mr. Best said.
Flaxseed offers other opportunities
besides products with omega-3 fatty acids. Flaxseed is about 28% fiber and is a source of lignans, which have been shown in laboratory studies of animals to help protect against certain kinds of cancer, according to the Flax Council of Canada.
Gluten-free products are another opportunity. Whole grain milled flaxseed contains zero gluten, Mr. Best said, but it does contain a film-forming soluble fiber called arabinoxylan that simulates many properties of wheat flour. Sterling Choice whole milled flaxseed from Enreco may be used in gluten-free pasta, waffles, bread, cookies, crackers, breadings and pizza crust.
Consumers may have a healthy opinion of flax, but what about its omega-3 fatty acid? According to a 2007 survey from the Flax Council of Canada, awareness of omega-3 fatty acids was over 50%, Ms. Fitzpatrick said. Awareness of ALA was 10%.
"Consumers are very aware of flax, but not ALA," she said. "They know flax. They really like flax."
European panel approves one of two ALA claims
A cause-and-effect relationship has been established between the dietary intake of alpha-linolenic acid (ALA), which is found in flaxseed, and the reduction of blood cholesterol concentrations, according to an opinion released this year by the European Food Safety Authority Panel on Dietetic Products, Nutrition and Allergies. To bear a claim, a food should contain at least 15% of the proposed labeling reference intake value of 2 grams of ALA per day, according to the panel.
The EFSA panel denied another claim for ALA, an omega-3 fatty acid. It ruled the evidence provided was insufficient to establish a cause-and-effect relationship between the dietary intake of ALA and the maintenance of normal blood pressure.
This article can also be found in the digital edition of Food Business News, October 13, 2009, starting on Page 33. Click