Flaxseed Oil | The Paleo Diet®
noun_Search_345985 Created with Sketch.
noun_Search_345985 Created with Sketch.

The latest from The Paleo Diet®, just for you.

Hot topics, new recipes, and science

Flaxseed Oil

By The Paleo Diet Team
March 12, 2010
Flaxseed Oil image

I recently visited family and my brother is a new advocate of the paleo diet. For breakfast he made us "fakecakes" which had about 1-2 tablespoons of flaxseed in them that he ground in a coffee grinder. I had few a questions regarding the use of flaxseed in the Paleo Diet.

First, why are flaxseeds ok in the Paleo Diet but other grains (seeds) are not? My understanding for eliminating grains from the diet is the toxins that they contain, but flaxseed contains large amounts of cyanogenic glycosides, producing up to 139 mg/kg of hydrogen cyanide in raw human-grade flaxseed. I am sure flaxseeds are processed somehow before selling them but I don't know what process that is or what effect it has on the HCN concentration.

So, secondly...do you know of any studies on the amount of HCN in meals containing ground flasxseed and the chronic oral exposure of those amounts on humans? My understanding here is the HCN that isn't hydrolysed to formic acid in the stomach and doesn't bind to hemoglobin is converted to thiocyanate which hinders thyroid function.

Thank you for your time and any information you can supply.

Sincerely,
Tim

Maelán Fontes' Response:

Hi Tim,

We think your thoughts are on the right track.

When Dr. Cordain wrote The Paleo Diet book, the advice to consume flaxseed oil was an attempt to balance the increased omega-6/omega-3 fatty acid ratio due to the exaggerated intake of omega-6 vegetable oils, especially linoleic acid, in the typical western diet.

Nevertheless, animal foods (fish, muscle meat and organs from wild animals) are good sources of w3 fatty acids. Therefore, when people eat these foods regularly along with vegetables and nuts, and avoid vegetable oils (especially oils rich in Linoleic Acid – Omega 6), they get a balanced intake of omega 3, omega 6, monounsaturated and saturated fatty acids. In this situation, there is no need for flax seeds to provide Omega 3 fatty acids and balance the Omega 3/Omega 6 ratio.

Here are some facts that support the notion that animal foods, vegetables and nuts provide the necessary Omega 6 and Omega 3 fatty acids in the right proportion:

  1. Hunter-gatherers do not eat ALA from seeds or vegetable oils.
  2. Nuts, green leafy vegetables and animal foods contain ALA.
  3. The conversion of ALA to EPA+DHA is limited, due to low delta-6 and delta-5 activity, although ALA is highly oxidized (twice that of LA) (see paper by Freemantle et al). This means that at some point in history we included preformed sources of EPA and DHA and still need to do so. Animal foods (especially brain from wild ruminants and fish) are very good sources of these fatty acids.
  4. The essentiality of LA & ALA in human metabolism has been questioned (see paper by Le et al.), as we relied almost on LCPUFA (Arachidonic Acid, EPA and DHA) during the Palaeolithic era (see Dr. Cordain’s papers on that here and here). Moreover, there is already some evidence showing that human metabolism could re-convert AA and DHA into LA and ALA respectively, hence AA and DHA would be the true essential fatty acids.
  5. The possible toxicity from seeds and vegetable oils (HCN, saponins, lectins).
  6. They are not used by current HG societies, and these populations show no signs of western disease, so this means that flax seeds are not necessary.
  7. The well known positive health effects of fish oil supplementation (among other factors to improve omega-6/omega-3 ratio) in contrast with some possible adverse effects of flaxseed oil (like the epidemiological evidence that points towards increased risk of prostate cancer with flax oil consumption – see paper by Brouwer et al).

The bottom line from an evolutionary perspective is that flax seeds and/or flaxseed oil would not have been consumed by pre-agricultural humans. However, having said that, hunter gatherers always would have preferentially sought high oil plant foods as per optimal foraging theory. But, most high fat plant foods contain high MUFA (with the exception of coconut and palm oils).

Hope this helps,
Maelán Fontes Villalba - MS Ph.D. candidate in Medical Sciences at Lund University, Sweden

Even More Articles For You

Vitamin E: The Paleo Perspective
Symptoms of vitamin E deficiency are rare, but according to at least four national surveys, most Americans consume less than the RDA of this vital nutrient.
By Christopher Clark
Zinc: Optimum Intake and Sources for the Paleo Lifestyle
Learn more about zinc and the paleo diet for a healthy lifestyle. The Paleo Diet® is your trusted source for quick paleo meals, paleo diet tips & more.
By Kyle Cordain
Gum Disease and Nutrient-Dense Food Supplements
Can nutrient-dense food supplements fight off gum disease? Alvin Danenberg, D.D.S. tested the effects of three supplements in treating periodontitis.
By The Paleo Diet® Team
Paleo Leadership
 
Trevor Connor
Trevor Connor

Dr. Loren Cordain’s final graduate student, Trevor Connor, M.S., brings more than a decade of nutrition and physiology expertise to spearhead the new Paleo Diet team.

Mark J Smith
Dr. Mark Smith

One of the original members of the Paleo movement, Mark J. Smith, Ph.D., has spent nearly 30 years advocating for the benefits of Paleo nutrition.

Nell Stephenson
Nell Stephenson

Ironman athlete, mom, author, and nutrition blogger Nell Stephenson has been an influential member of the Paleo movement for over a decade.

Loren Cordain
Dr. Loren Cordain

As a professor at Colorado State University, Dr. Loren Cordain developed The Paleo Diet® through decades of research and collaboration with fellow scientists around the world.