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While the stereotype of pregnant people wanting ice cream and pickles does hold true for many, other folks prefer to incorporate more nutrient-packed options — like seeds — into their pregnancy diet.

This type of diet may include flaxseeds. But there’s a lot we don’t know about the effects this “superfood” could have on your growing baby.

Flaxseeds come from the flax plant. This flowering plant has multiple functions, including commercial uses, such as a fiber spun into linen and paint production.

You can consume the seeds in multiple forms. Flaxseeds can be:

  • left whole
  • ground into meal
  • processed into flaxseed oil, also known as linseed oil

Flaxseeds are high in fiber and protein, making them a popular superfood choice for people who want to improve their nutritional consumption and overall health.

They’re also popular for easing constipation, according to a 2014 review. Studies have also suggested that flaxseeds may help reduce LDL cholesterol, as reported in a 2019 review.

Likewise, a 2015 review linked flaxseeds to reduced blood pressure and a 2017 review suggested that it aids in weight loss for people with a body mass index (BMI) higher than 27.

There are conflicting answers to this question. In the United States, pregnant people are often told to avoid consuming flaxseeds in any form.

In Canada, consuming flaxseeds whole or ground is considered safe, as long as you do so in moderation. If you follow Canadian standards, experts recommend consuming no more than 45 grams of flaxseeds per day.

So, if you’re unsure, it’s best to speak with your physician or a dietician for guidance or alternative options.

Much like many other foods and supplements, when it comes to the impact on pregnancy, research into adverse effects is limited due to ethical reasons.

As a result, even the National Institutes of Health (NIH) admits that research into the impact of flaxseeds in whole or ground form in pregnant or breastfeeding people is scant.

So, the NIH can’t definitively say that the food should be completely avoided. Other experts recommend waiting until after the first trimester to begin consuming flaxseeds.

But most agree that the oil from flaxseeds isn’t safe — in any amount — during pregnancy.

If you previously consumed flaxseed oil regularly, you’ll want to switch to whole or ground meal instead. The oil has been linked to premature births, especially when consumed in the final two trimesters.

Also, the oil shouldn’t be used topically during pregnancy.

It’s important to clarify that most peer-reviewed studies researching the adverse effects of flaxseeds on pregnancy — and the increased risk of hormonal imbalances in offspring — are limited to experiments performed on rats.

This is the main reason why advice for consuming flaxseeds during pregnancy is conflicting.

However, several studies performed on rats found that consuming too much flaxseed while pregnant or breastfeeding increased hormonal levels — and later increased the risk of developing breast cancer later in life in the rat’s offspring.

Still, keep in mind that not everything that happens to other members of the animal kingdom is for sure going to happen to humans.

And since few, if any, studies have been performed on humans, we can’t automatically assume people will experience the same effects.

One of the biggest benefits of flaxseed is that it’s a great source of omega-3 fatty acids. The omega-3s found in flaxseeds are specifically known as alpha-linolenic acid (ALA).

While everyone needs omega-3s, they’re especially beneficial when you’re pregnant and growing another little human. During pregnancy, omega-3s contribute to baby’s brain development, which is especially essential in the first trimester.

Though the omega-3s found in flaxseed differ from those found in most pregnancy-safe fish, it’s not the only planted-based omega-3 (ALA) source available to you if you’re concerned about adverse effects.

Other sources include spinach and kale. And fish sources of omega-3s include:

  • sardines
  • sea bass
  • mackerel
  • salmon
  • rainbow trout
  • shrimp

Also, flaxseed is an excellent regulator for blood sugar levels — a serious concern for some people during pregnancy. The seeds may also help to manage pregnancy-related constipation, according to a 2011 review.

Flaxseed can cause digestive issues. This happens when you consume fiber-rich flaxseeds but fail to drink enough liquid to aid in digestion.

Common signs that you’re not drinking enough water while consuming flaxseeds include:

  • bloating
  • diarrhea
  • gas
  • upset stomach

But these are side effects that can happen to anyone — not just during pregnancy.

Flaxseed is known to be contraindicated for some medications. This means that it can negatively impact how certain medications behave once you take them.

In particular, flaxseed can react negatively with cardiovascular and diabetic medications. This may lead to:

  • poor blood clotting
  • low blood sugar levels
  • even lower blood pressure

Also, raw flaxseed tends to have more of a negative impact than flaxseed that’s been cooked.

In raw form, along with the increased fiber, flaxseed contains trace amounts of cyanide compounds. When cooked, those compounds are broken down and made harmless.

Just like with pregnancy, the recommendations for breastfeeding are somewhat conflicted because of limited research on the topic.

While there isn’t a consensus on flaxseeds themselves, flaxseed oil shouldn’t be consumed until you’ve weaned your baby.

The choice to consume flaxseeds when you’re pregnant is going to depend on your comfort level.

Given the inconclusive and conflicting stances within the medical and scientific communities about flaxseed during pregnancy, it might be better to err on the side of caution.

Avoiding the much more concentrated flaxseed oil in pregnancy and breastfeeding is wise.

If you ate flaxseeds before your pregnancy, we recommend speaking with your physician or dietician before you continue eating it while you’re pregnant.