Flax Seeds


Flax seeds (also known as flaxseed) provide many of the advantages of chia seeds but are slightly less practical because of their hard seed coatings and are also less stable because they lack the unique antioxidant content of chia.

Although historically flax has been used extensively for industrial purposes, the seeds have become popular in more recent times as a dietary source of alpha linolenic acid (ALA).

Flaxseed is a rich source of lignans, which may have benefits for fighting cancer and lowering cholesterol, although more research is required.


Flax, also known as linseed, is the common name for Linum usitatissimum. The plant has been cultivated since ancient times for its fibers, seeds and seed oil. The fibers and oil have been used in many industrial processes throughout history, although the use of the seeds as food is slightly less well established.

As with chia, scientific research studies for flaxseed are not plentiful, although there is no shortage of marketing material based on their health benefits.

For this project we examined a very small number of published research articles, which provided limited insight, and consulted a small number of web sites and books.

We formulated a series of questions that we have then attempted to answer by studying the A&C book and, to a lesser extent, the other research material.

The questions that we have addressed during this project are:

What is the history of flax as a food?
What is the nutrient content of flax?
Is there a contamination issue?
How stable are flax seeds compared to other seeds?
What side effects are there?
What specific benefits do they provide?
How can flax seeds be incorporated into our diet?
Does flax need to be approved for use as a food?

What is the history of flax as a food?

Whereas Ayerza & Coates (A&C) provide a detailed account of the extensive history of chia seeds as a food, primarily in mesoamerica, there does not appear to be an equivalent record available for flax. A&C assert that flax has never played a significant role historically in the human diet.

A few sources, including Artemis Simopoulos's book The Omega Diet, state that flax seeds were used as food by the ancient Greeks and Romans, who added them to their bread, and also the ancient Egyptians and Hebrews. Apparently, Hippocrates promoted the use of flax for the treatment of inflammation.

We have so far been unable to establish, via original research sources, the extent to which flaxseed played a role in ancient diets. It seems certain, however, that flax was one of the earliest cultivated crops. The flax plant has been grown for thousands of years for its fiber, used to make linen clothing, and oil, from which paints and varnishes have been manufactured.

What is the nutrient content of flax?

An Important Food for Vegetarians: In common with chia and other plant sources of n-3, flax seeds do not contain EPA and DHA. They are a very rich source of ALA, however, and provide complete protein, fiber, minerals, B vitamins and lignans.

The PUFA content of flaxseed is comparable to that of chia seeds. The USDA database gives 22.8g of ALA per 100g of flaxseed compared with 17.6g for chia seeds, with omega 6 levels (primarily LA) being very similar.

Aside from fatty acid composition, flax has some marked similarities to chia in terms of its high fiber content and complete protein (although chia seems to have a small advantage in both of these areas). In other respects, such as mineral and vitamin content, there are more apparent differences.


According to A&C, ALA makes up 57.5% of the total fatty acids in flaxseed, while LA makes up 15%, giving a ratio of 3.83 1 n-3 to n-6 (compared with 3.36 for chia).


Like chia, flaxseed is a source of complete, high quality protein. It is therefore likewise particularly valuable to vegetarians and vegans.


The USDA database shows that flaxseed is an excellent source of minerals, losing out to chia only in its calcium content, which is nevertheless worthwhile.


The USDA database lists significant quantities of the B vitamins Thiamin, Riboflavin and Niacin, together with vitamin B6 and folic acid.


Flaxseed does not benefit from the antioxidant component of chia seeds and hence does not have the same potential for long-term storage. It is, however, rich in lignans, which act like antioxidants in certain respects (see below).

Dietary fiber

Flaxseeds are an excellent source of dietary fiber, although they contain less than two thirds of the levels found in chia seeds, with a total content of 27.3g compared with 37.7g for chia, according to the USDA database.


Flax seeds, together with sesame seeds, are one of the best known sources of lignans, a class of phytoestrogens. Although lignans are thought to act like antioxidants and are believed to have powerful anti-cancer properties, we have not so far found any research studies to substantiate these ideas.

Is there a contamination issue?

It is widely acknowledged that flaxseed contains small quantities of neurotoxins including cyanogenic glycosides. It is generally accepted that these compounds do not constitute a health risk if flaxseed is consumed in moderate quantities.

How stable are flax seeds compared to other seeds?

Although flax seeds contain the antioxidant-like lignans, they do not possess the inbuilt antioxidant protection of chia seeds and hence are less stable and more prone to lipid oxidation. Their shelf life is thus shorter, especially when they are exposed to oxygen after grinding or extracting their oil.

A Shorter Shelf-life: Due to their protective coating, flax seeds are far more stable than flaxseed oil. They have a much shorter shelf-life than chia seeds, however, because they do not have the same in-built antioxidant protection. Keep them in the refrigerator or freezer for months rather than years.

What side effects are there?

The limited research sources found did not indicate any adverse effects associated with consumption of flaxseed beyond the cautionary statements relating to potential toxic effects and possible intestinal blockages where extremely large quantities are consumed.

What specific benefits do they provide?

The benefits of flax seeds can be summarized as follows:
Learn about the nutritional benefits of ALA

How can flax seeds be incorporated into our diet?

Use a Coffee Grinder: Flax seeds have a much harder coating than chia seeds. You will therefore need to convert them to a powder using a coffee grinder before adding them to recipes. Use your imagination to incorporate them into a variety of dishes.

Flax seeds have hard coatings that are not easily broken down by our alimentary systems. It is therefore necessary to grind the seeds.

The ground seeds can be used in the following ways:

Does flax need to be approved for use as a food?

According to A&C, some countries have restricted the use of flaxseed as a form of food. We have not yet found any detailed information about this form of restriction.

Go to Part 4 - Perilla and Sacha Inchi Seeds

Return to Part 1 - Overview