What Are The Side Effects Of Flaxseeds?


5 Min Read

The mucilage in flaxseeds can have a strong laxative effect and can significantly increase the number of bowel movements you have in a day. Their estrogen content can alter the menstrual cycle, interfere with sexual development, and fertility if taken in excess. Flaxseeds are also known to cause mild rhinitis/asthma, nausea, allergic reactions during pregnancy.

Flaxseeds – these tiny, nutty seeds are the talk of the town, making an appearance in a variety of salads, soups, and smoothies. Flaxseeds contain some powerful nutrients and have earned their bragging rights. But are they really suitable for everyone, or do these diminutive seeds have side effects you need to watch out for?


The Good Stuff

Flaxseeds have hit the headlines for all the right reasons, with the goodness of omega 3 fatty acids, antioxidant lignans (the naturally occurring form of estrogen), micronutrients such as copper and magnesium, vitamins B1,B2, and B6, and mucilage packing a punch in every seed.1 Doctors and nutritionists are recommending them as a dietary supplement. Numerous studies vouch that they can help lower cholesterol, aid weight loss, and even lower the risk of cancer. They can also help keep your skin, nail, and hair healthy.2

Side Deals

Is the picture all rosy though? While flaxseeds are mother nature’s answer to many of our ailments, there are a few possible side effects you need to look out for.

Gastric Trouble


One likely effect is on the digestive system. Eating flaxseeds can have gastrointestinal side effects and can significantly increase the number of bowel movements you have in a day. This means multiple trips to the bathroom to alleviate bloating, stomach pain, constipation, diarrhea, and the like. There are two reasons why things could go a bit off track with flaxseeds, especially when you overdo them. One, the high fiber content of flaxseeds can be too much at times for some of us with a more delicate digestive system. Second, the mucilage in flaxseeds can have a strong laxative effect. As much as it can help in both diarrhea and constipation, flaxseeds can also backfire (pun unintended!) and have the reverse effect.3 Flaxseeds should ideally be had with water or other fluids – else, it could worsen constipation and even cause an intestinal block.4

Hormonal Excesses


The phytoestrogenic nature of flaxseeds can have a downside. It’s often a mixed bag for some women – flaxseeds can help treat hormonal imbalances and ease menopausal difficulties like hot flashes on one side but they can also significantly alter the menstrual cycle on the other. The estrogen content can even interfere with sexual development and fertility if taken in excess.5

Allergic Reaction

If you are prone to allergies, especially related to cereals or grains, check for any possible allergic reaction to flaxseeds before you include them in your diet. The seeds have been known to cause vomiting, nausea, and allergic reactions, even leading to life-threatening anaphylaxis in some cases.6 It can truly be an occupational hazard if you work in close proximity to flaxseed powder, maybe as a chef or baker (the powder is a great egg substitute too). It has been found to cause mild rhinitis or asthma when inhaled regularly.7

During Pregnancy


Pregnancy is a time to exercise extra caution about what you eat and don’t eat. Even seemingly harmless natural foods can cause an untoward reaction so it’s best to check with your doctor if are veering off your regular diet. As it turns out, flaxseed oil is to be avoided by pregnant women, especially in their second or third semester – the risk of premature birth and low birth weight has been found to increase almost four times.8

Other Medication

We know that flaxseeds are high in fiber and tend to block the digestive passage in a way. They can also reduce the absorption of other medicines or supplements and are best avoided when you are taking other oral medication.9 They may also interfere with or modulate the effect of certain medication like blood thinning or blood sugar medicines. So talk to your doctor before you add them to your diet.10

How Much is Good For You


Doctors recommend just a spoonful a day for the seed to work its magic. Best that the seeds are soaked or powdered before eating for easier absorption by the body. In fact, flaxseeds in whole or oil form can be quite difficult for the digestive tract to process and can lead to severe gastrointestinal issues when consumed regularly.11

Goodness Prevails

So is this one more superfood flying out the window? Not necessarily! The goodness of flaxseeds far outweighs the possible downsides. Add the powder to just about anything – flour, batter, cereals, smoothies, or just plain yogurt, and your body has a lot to be thankful for – cardiovascular protection, a healthy digestive system, and hormonal balance being key. So do get in those flaxseeds, but remember, moderation is the operative word!

References   [ + ]

1.Morris, Diane H. “Essential nutrients and other functional compounds in flaxseed.” Nutrition Today 36, no. 3 (2001): 159-162.
2.Oomah, B. Dave. “Flaxseed as a functional food source.” Journal of the Science of Food and Agriculture 81, no. 9 (2001): 889-894.
3.Palla, Amber Hanif, and Anwarul-Hassan Gilani. “Dual effectiveness of Flaxseed in constipation and diarrhea: Possible mechanism.” Journal of ethnopharmacology 169 (2015): 60-68.
4, 9.Flaxseed and Flaxseed Oil, National Center for Complementary and Integrative Health.
5.Barrett, Julia. “Phytoestrogens. Friends or foes?.” Environmental Health Perspectives 104, no. 5 (1996): 478.
6.Alvarez-Perea, A., D. Alzate-Pérez, A. Doleo Maldonado, and M. L. Baeza. “Anaphylaxis caused by flaxseed.” J Investig Allergol Clin Immunol 23, no. 6 (2013): 446-447.
7.Vandenplas, Olivier, Vinciane D’Alpaos, M. Cesar, Stéphanie Collet, M. Tafforeau, and J. Thimpont. “Occupational asthma caused by linseed oilcake.” Allergy 63, no. 9 (2008): 1250-1251.
8.Moussally, Krystel, and Anick Bérard. “Exposure to specific herbal products during pregnancy and the risk of low birth weight.” Alternative Therapies in Health & Medicine 18, no. 2 (2012).
10.Possible Interactions with: Flaxseed Oil, University of Maryland Medical Center.
11.Austria, J. Alejandro, Melanie N. Richard, Mirna N. Chahine, Andrea L. Edel, Linda J. Malcolmson, Chantal MC Dupasquier, and Grant N. Pierce. “Bioavailability of alpha-linolenic acid in subjects after ingestion of three different forms of flaxseed.” Journal of the American College of Nutrition 27, no. 2 (2008): 214-221.
CureJoy Editorial

The CureJoy Editorial team digs up credible information from multiple sources, both academic and experiential, to stitch a holistic health perspective on topics that pique our readers' interest.

CureJoy Editorial

The CureJoy Editorial team digs up credible information from multiple sources, both academic and experiential, to stitch a holistic health perspective on topics that pique our readers' interest.