Originally cultivated in Babylonia and prehistoric Europe, flax (linum usitatissimum) is an herbaceous plant that yields many benefits. From its fibrous stalks, we create linen; while from its edible seeds, we produce flaxseed oil. For thousands of years, humans have been consuming flax in some form for its nutritional and medicinal value. Even Hippocrates, the “Father of Medicine,” prescribed it to treat a variety ailments.
Historically, flax has been used as a pain reliever, a diuretic, an expectorant, an astringent, and a laxative. And today, flaxseed still enjoys a reputation as a heart-healthy food that’s easy and affordable to bring into your diet. Here’s what you need to know to get the most of out this valuable nutrient.
Flax is an excellent source of essential omega-3s.
Omega-3s are essential fatty acids (EFAs), which are common to many seed and nut oils. Just as amino acids build proteins, EFAs build prostaglandins: hormone-like compounds that affect reproductive health and may also play a role in regulating blood pressure and inflammation, platelet aggregation, and pain sensitivity.
Like their counterparts, the omega-6s, omega-3s are necessary to our survival, but cannot be made by our bodies. Instead, they must be sourced from the food we eat. As an unrefined food, flaxseed provides the richest source of omega-3s fatty acids. In fact, some farmers include flaxseed in their chickens’ diets to boost the omega-3 content of their eggs.
Omega-3s play an integral role in cells throughout our bodies, especially on receptors in cell membranes. Flaxseed is especially high in alpha-linolenic acid (ALA): the precursor to eicosapentaenoic acid, (EPA), the omega-3 found in fish oil. Not only does that give it the ability to boost immunity, it may also help prevent the loss of magnesium and calcium. (13, 14)
It’s cancer-fighting and heart-healthy.
For hundreds of years, flax was used to treat various tumors; and as it turns out, that folk remedy was not misguided. In the 1970s, researchers discovered that flax does contain cancer-fighting agents. (4) And in a more recent Canadian study, flaxseed was found to have the ability to lower total cholesterol levels (including “bad” LDL cholesterol), while having no adverse effects on “good” HDL cholesterol. (15)
The lipid-lowering effect of flaxseed (but not its oil) can be attributed to its high fiber content, which likewise lends itself to a healthy digestive tract by warding of constipation, diverticulosis, type 2 diabetes, and cardiovascular disease (CVD), to name a few. In addition to omega-3s and fiber, it’s also a great source of the following:
From protecting against stroke, to lowering triglycerides, to decreasing inflammatory responses, there’s no denying that flaxseed is a powerhouse nutrient. But that’s not all
It has all the plant lignans you need.
Lignans are natural chemicals found in plants that have antioxidant properties. (16) They are often referred to as phytoestrogens; and when metabolized by the body, they can have profound effects on hormone-sensitive cancers (such as breast, uterine, and prostate) by decreasing cell proliferation and inhibiting enzyme activity. (18, 19)
Research is ongoing as to whether or not high-circulating levels of lignans can prevent these kinds of hormone-related diseases. However, if you’re looking to get more lignans into your diet, flaxseed is the way to go. You can also find them in other seeds (such as pumpkin, poppy, and sunflower), whole grains, brans, and berries.
Get the most out of flaxseed.
Like most foods, it matters how flaxseed is consumed and digested—as this directly affects how well the body can absorb different nutrients.
According to NutraIngredients-USA, plant lignans found in flax are more bioavailable when the seeds are crushed or ground, rather than whole. (7) Meanwhile, lignans are not present in flax oil at all unless flaxseed is added. And as with fish oil—another popular source of omega-3s—the extraction process has the potential to damage polyunsaturated fats: generating peroxides that ultimately do the body more harm than good.
Here are some dos and don’ts to keep in mind for sourcing and cooking with flaxseed:
Ackman RG. The absorption of fish oils and concentrates. Lipids. 1992 Nov;27(11):858–62.
Bryhn M, Hansteen H, Schanche T, Aakre SE. The bioavailability and pharmacodynamics of different concentrations of omega-3 acid ethyl esters.
Prostaglandins Leukot Essent Fatty Acids. 2006 Jul;75(1):19–24. Epub 2006 Jun 27.
Dyerberg J, Madsen P, Møller JM, Aardestrup I, Schmidt EB. Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent
Fatty Acids. 2010 Sep;83(3):137–41.
E. Ibáñez, J.A. Mendiola, M. Castro-Puyana. Supercritical Fluid Extraction Encyclopedia of Food and Health, 2016, Pages 227–233
Rui P.F.F. da Silva, Teresa A.P. Rocha-Santos, Armando C. Duarte. Supercritical fluid extraction of bioactive compounds. TrAC Trends in Analytical Chemistry, Volume 76, February 2016, Pages 40–51
West AL, Burdge GC, Calder PC. Lipid structure does not modify incorporation of EPA and DHA into blood lipids in healthy adults: a randomised-controlled trial. Br J Nutr. 2016 Sep;116(5):788–97.