Flaxseed Oil Alert: Don’t Take When Pregnant

From a press release:

A study has found that the risks of a premature birth quadruple if flaxseed oil is consumed in the last two trimesters of pregnancy. The research was conducted by Professor Anick Bérard of the Université de Montréal’s Faculty of Pharmacy and the Sainte-Justine Hospital Research Center and Master’s student Krystel Moussally.

In Canada, 50 percent of pregnant women take prescription medication. Yet many of them prefer to use natural health products during the pregnancy. “We believe these products to be safe because they are natural. But in reality, they are chemical products and we don’t know many of the risks and benefits of these products contrarily to medication,” says Bérard.

Bérard and Moussally set out to conduct one of the largest studies ever undertaken on by analyzing data from 3354 Quebec women. The first part of the research established that close to 10 percent of women between 1998 and 2003 used natural health products during their pregnancy. Before and after pregnancy they were respectively 15 and 14 percent to use these products. The increase means that about a third of women consuming natural health products stopped during the pregnancy.

The most consumed natural health products by pregnant women are chamomile (19 percent), green tea (17 percent), peppered mint (12 percent), and flaxseed oil (12 percent). Bérard and Moussally correlated these products to premature births and only one product had a very strong correlation: flaxseed oil.

“In the general population, the average rate of premature births is 2 to 3 percent. But for women consuming flaxseed oil in their last two trimesters that number jumps up to 12 percent,” says Bérard. “It’s an enormous risk.”

The correlation existed only with flaxseed oil, yet women consuming the actual seed were unaffected. Even if more studies must be undertaken to verify these results, Bérard recommends caution when it comes to consuming flaxseed oil.

Thanks to Joyce Cohen.

3 Responses to “Flaxseed Oil Alert: Don’t Take When Pregnant”

  1. MT Says:

    Sounds like about 350 women would have been taking flax, and about 40 premature births would have been seen from that group. Very striking. Could anything else have explained this? A different type of interaction or another aspect of lifestyle from the type of women who use supplements? What else was controlled for? It would be interesting to see this contrasted with other types of Omega-3 supplementation. I’m assuming it is another constituent of the flax causing this — maybe the lignans?

    If that is the case, I would wonder whether the problems flax creates in pregnancy isn’t having some smaller effect on general consumers, which is not noticed because the O3s are offsetting a still greater problem.

    Would be interesting to know quantities. Most people probably only take a few of the capsules a day, so if these women were taking such small quantities that is really alarming.

  2. Patri Friedman Says:

    This is quite strange, since omega-3s, in other studies I’ve read, reduce the risk of prematurity. (Prematurity is related to inflammation, omega-3s reduce systemic inflammation).

  3. Mini Moo Moo Says:

    We needed this info. It has just settled a disagreemnt! *Bookmarked*