Researchers from St Boniface Hospital Research Centre in Winnipeg, Manitoba compared whole seed, milled seed, and flaxseed oil.

First, the details.

  • The flaxseed components (30 grams of seed or 6 grams of alpha-linolenic acid [ALA] in the oil) were baked into muffins and eaten over a 3 months by healthy adults.
  • Comparisons were made among the following.
    • Whole seed
    • Milled seed
    • Flaxseed oil

And, the results.

  • At 1 month there were significant increases in ALA blood levels with flaxseed oil and the milled flaxseed.
  • ALA levels were significantly higher with milled flaxseed vs flaxseed oil.
  • Eating muffins supplemented with whole flaxseed did not result in a significant increase in ALA.
  • 2 more months of flaxseed ingestion did not achieve significantly higher blood levels of ALA in any group.
  • There was no significant increase in eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) blood levels in any groups.
  • There were no changes in cholesterol or triglycerides, or in platelet aggregation.
  • All groups experienced some gastrointestinal discomfort during the early stages of the study, but this disappeared with oil and milled seed.
  • Compliance with treatment was a problem with whole flaxseed.

The bottom line?
The authors concluded, “Flax oil and milled flaxseed delivered significant levels of ALA to the plasma, whereas whole flaxseed did not.”

The gastrointestinal side effects with whole seed and oil preparations were severe enough to cause withdrawal of some participants — although the abstract doesn’t give details. Everybody in the milled flaxseed group completed the study. Therefore, it might represent a good form of flaxseed in order to avoid side effects and still provide significant increases in ALA to the body.

Background on the 3 major types of omega-3 fatty acids is here.

8/12/08 22/53 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.