Why Flax Seeds Aren’t As Good As They’re Claimed To Be
Photo courtesy of Dakota Flax
Flax is commonly touted as a good way for everyone to get their omega-3 fatty acids. Add some to your cereal. Grind it on your toast. Add the oil to your salad dressing. Bad news for vegetarians today: I’m dispelling the rumor that flax is a good way to get your omega-3s.
Here is the simple reason that adding flax seeds or oil doesn’t work the way you’d like it to: flax contributes an omega-3 known as Alpha-linolenic acid (ALA). The problem with ALA is that it’s a short-chain fatty acid, only 18 carbons long, while the body needs the long-chain fatty acids known as Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). Just remember the acronyms, there’s no reason to memorize those names.
So the body converts the short-chain ALA to the long-chain EPA and DHA. Unfortunately, this process is very inefficient, on the order of 5-10%. Ironically, the higher your intake of saturated fat, the more efficient this process is. But most people that are taking flax are very health-conscious and avoid saturated fat like the plague (that is a gross generalization, no source for that).
Converting ALA To EPA & DHA
Here’s a bit of technical jargon. Warning: more information than you really wanted ahead! Skip the next few paragraphs if you don’t care. When you take in ALA, the body has to convert it to EPA and DHA through several rounds of desaturating and elongating. Here is a basic flowchart of the actions of the desaturation and elongation steps. You can see in the upper-left corner, you have ALA, which is acted upon by delta-6 desaturase to form Stearidonic acid, another 18-carbon omega-3. This fatty acid is elongated by the insertion of an ethyl group to form Eicosatetraenoic acid, 20-carbons long; we’re getting closer. A little action from delta-5 desaturase gives us EPA, but we’re still 2 carbons short for DHA. Once again, we have to elongate to get Docosapentaenoic acid and then let delta-4 desaturase convert it to DHA.
It all sounds so simple, but that doesn’t take into account things that can inhibit that action of the desaturases. For instance, alcohol, diabetes, sugar, and aging all inhibit delta-6 desaturase, meaning that each of those items reduce the efficiency of the first step of converting ALA to EPA. Delta-5 desaturase is inhibited by EPA, meaning that the body works to slow down EPA production when EPA is high. High levels of omega-6 in the diet can also affect the conversions. There are likely other elements of lifestyle that inhibit the action of these desaturases.
Technically, flax is a good source of omega-3; it’s just the wrong form of it. So from a purely logical standpoint, it makes sense to focus on getting the EPA and DHA that the body uses directly rather than taking a precursor and hoping for the best.
And the best sources of EPA and DHA are animal products, specifically fish and grass-fed meats. The best sources are (in order) cold water fish, grass-fed meat, and eggs (properly raised eggs!). However, I find that to get a nice high intake of omega-3, supplementation is required, specifically supplementation with cod liver oil and fish oil. I use Carlson’s Very Finest lemon flavored oil and take a tbsp of both cod liver and fish oils per day for a total of 3g of DHA and 3.5g of EPA, give or take. The cod liver oil also contributes 2100-3600 IU of naturally-occurring vitamin A and 1200 IU of vitamin D.
Dealing With Inflammation
But here’s another kicker. One of the big benefits of omega-3s is their anti-inflammatory properties. Since we want to keep inflammation low, it makes sense to first avoid foods, activities, and lifestyle factors that cause inflammation and then to supplement our body to help it fight off the remaining inflammation. There appears to be conflicting information on whether supplementing with flax oil increases the amount of inflammation. Some studies say it increases inflammation, some say it does nothing, others say it decreases inflammation.
If you really need justification for increasing your omega-3 intake, omega-3s have been shown to reduce the risk of stroke and cardiovascular disease, help with depression, possibly stave off Alzheimer’s, and keep Type I Diabetes at bay. The list goes on and on; search PubMed for “fish oil” and any disease/condition you want to learn about. I bet you’ll find some way that omega-3s help. Fatty acid deficiencies are associated with declines in cognitive function (see Alzheimer’s above), increases in ADD, dry skin, allergies, fatigue, and decreased immunity.
The Omega-6/Omega-3 Ratio Is More Important
Most important though is the omega-6/omega-3 ratio. The typical American’s ratio is around 20:1, but it should be more in the range of 2:1 to 1:1. So along with increasing the amount of omega-3 you take in, you need to reduce the amount of omega-6 that you take in.
Major sources of omega-6 are the very foods that we’ve been told to eat lots of: vegetable oils and grains. A high omega-6 intake actually inhibits the body’s ability to use omega-3s because they occupy several of the same pathways.
Omega-6s are pro-inflammatory, while omega-3s are anti-inflammatory; optimally, they should balance. And finally, omega-6s promote tumor growth (like of the prostate), along with inflammatory and auto-immune disorders, all of which have taken off in the last half of the century.
Eat Foods Your Body Recognizes
I’m going to say the opposite: avoid vegetable oils and grains. They are unnatural substances that have no place in a healthful hunter-gatherer diet. If you’re eating a proper diet of meat, vegetables, nuts, seeds, oils, fruits, and tubers, you’re probably doing just fine. A little grain won’t hurt you, but a lot of grain will. And vegetable oils are quite likely rancid by the time you use them since polyunsaturated fats are so unstable, so ditch the corn and peanut oil and stick to olive, coconut, palm, and grass-fed animal fats.
It’s your call: flax seeds with a nice dose of hope or meat and seafood?
References:
ALA
EPA
DHA
Omega Conversion
Fatty Acid Deficiencies and ADD
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20 Reader Comments
Feel free to leave a comment below... and as always please keep it in good taste. Comment spamming ONLY to promote your website is NOT allowed. So please use your real name in the field below otherwise it may be edited or removed. Constructive discussion is always welcome, personal attacks or useless bickering is not. Not all comments may be answered directly by editors/writers.
Scott, couple great posts.
Comment though. The main page, after not coming up yesterday, now has a white body background and a light gray text making it hard to read. I had to highlight it to read without straining. If I clicked on a link to view just that post it was back to normal.
Joe
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Nutrition : Fats
1. 15 March 2003 | Filed under Author : Groves + Nutrition : Fats
Fatty Acids Requirements
You may be interested in the relative oxidation indexes of various oils and fats:
Coconut oil: 32.48
Butter: 142.12
Beef dripping: 178.40
Mutton fat: 231.20
Olive oil: 362.80
Canola oil: 544.80
Soy oil: 608.00
Udo’s oil: 933.60
Flax oil: 1035.20
Fish oil: 2172.80
While I haven’t been able to find the exact reference for the chemistry, I’ve seen it in other places. The reason being that polyunsaturated fatty acids are prone to oxidation and the Omega 3’s are more prone than Omega 6’s. With this in mind, refrigeration and minimizing exposure to oxygen is essential. I try to find fish oil pills that are combined with antioxidants such as Vitamin E and CoQ10. Krill Oil is expensive, but is combined with natural antioxidants. Also consumption in the natural state is desirable, i.e. consuming wild caught fish and free range meat and grinding up flax seed. While it is not necessarily the best source of Omega 3’s, ther is no reason to exclude it entirely given how unbalanced the 6 to 3 ratio is in our diet.
Thanks for the time and space to comment.
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Good information there Mark. The propensity of polyunsaturated, and even monounsaturated, fats to oxidize under heat is why I cook in coconut oil, palm oil, or tallow/lard nearly 100% of the time. Flax and fish oil definitely need to be stored in the fridge if they are oils. Capsules can go in the freezer.
Cheers
Scott Kustes
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[...] as the only source of omega-3 available to them is flax, which as we’ve discussed, isn’t a good source. Animals are the only good source of the long-chain omega-3s that make up the human brain. In fact, [...]
[...] it’s really not. Notice that the Quaker oats provide only 130mg of ALA, a paltry amount of an acid that is inefficiently converted to the EPA and DHA used by humans. But the average consumer doesn’t know that. They only know that the media says “eat [...]
[...] Stick to olive, coconut, and palm oils rather than those listed though. As we’ve discussed, ALA isn’t a good source of omega-3s for humans. Grains are omega-6 factories, so avoid them. Is it just me or does that [...]
[...] than omega-6, and this is of the alpha-linolenic acid variety, which as we’ve discussed is poorly converted into the EPA and DHA the human body needs. Take a look at corn, soy, peanut, and cottonseed. Is it any wonder that most [...]
Here is another reason that I don’t include flax in my diet, just as I don’t include soy, the phytoestrogen content is flax is way-high! You can do your own search, but here is one link: http://www.dietaryfiberfood.com/phytoestrogen.php
Also, I don’t buy the argument that phytoestrogens and xenoestrogens take-up the space that natural estrogen uses (the soy industry would love for you to buy this argument, as would the chemical industries), so consume lots of them to prevent estrogen over load. In our modern society/world, xenoestrogens are ubiquitous, so if you care about your health, you should do all that you can to keep your testosterone-to-estrogen levels high (both men and women). Just a few ideas to do your own search linking to this are: man-boobs (moobs), breast cancer, libido, weight gain, muscle mass, etc.
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The lower conversion rate is relevant, and I didn’t know about the phytoestrogens, but is there not an issue of heavy metals and other toxins in fish due to water pollution? It is advsed most people limit fresh fish for this reason, particularly tuna but also other fish, and taking fish oil as a supplement would mean getting still larger doses. Also, fat (oil) is the place where many of these toxins accumulate, making it a still more serious issue. Refined fish oil is supposed to get around this issue, but reliably certified and tested oil is hard to find.
Just some impressions, I would be interested in feedback on my comments in case they are mistaken on some point.
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Calvin, I concur about the phyto/xenoestrogen issue. I don’t think it’s a good idea to fill the body with plant estrogens.
Mazz, there are issues with toxins in fish, though in our modern world, there are toxins everywhere. It’s really a matter of reducing your toxin load as much as possible. That means not eating the fish high up in the food chain very often (shark, swordfish, etc). The question is “do the benefits of fish oil and fish overcome the potential drawbacks of PCBs and mercury?” I think if we’re sticking to smaller fish such as sardines, along with salmon, and high quality fish oils like Carlson’s or Blue Ice, the benefits are much much greater.
Cheers
Scott
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[...] Modern Forager: The Vaunted Flax Seed [...]
Hi Scott,
Great blog; good post,
A few more ideas on flax to stir things up: Whether your idea of healthy eating is primal (as in Mark Sisson’s awesome blog), evolutionary, or paleo, I doubt that flax seeds, much less flax oil have ever played much of a role in the diet of humans (same with canola, soy, corn, peanut, and most other vegetable oils). Fish on the other hand has. Something to also consider is that super unsaturated oils (Omega 3’s) are only found in abundance in the northern latitudes, and cold water, hence look at where flax grows and where the best sources of Omega 3’s from fish come from (reason: their double bonds both remain fluid at cold temperatures for the sake of stability at warm ones). Compare this to the latitudes where coconut and palm grow (sources of saturated coconut and palm oil which are both saturated and very resistant to oxidation; they’re also heat/light stable). The reason that omega 3’s are not found in in any quantity in the tropics is because of how easily these highly unsaturated oils oxidize, both in nature, and once consumed,–this is very important! Oxidation happens in the presence of light, oxygen, and extended exposure to heat or just high heat. Imagine what happens, for example, when humans living at middle latitudes supplement with lots of omega 3’s, and have 9-12 months of intense UVA/UVB sunlight. Compare this to people living in northern latitudes which receive much lower intensity and duration of light (on an annual basis)–same thing as the polyunsaturates (Omega 6’s), but these are super polyunsaturates–therefore even more reactive–they turn rancid, unless there are lots of antioxidants present. Just on example of this are the ever visible lipofusion (age spots), in the skin.
From an evolutionary perspective, I think that only species (including humans) living in the northern latitudes (again, compare to species living in the middle latitudes and tropics) should eat/supplement with higher quantities of omega 3’s (and even then limit the amounts–more isn’t always better–especially in the case of super unsaturates), and these should come from cold water fish, or from the fat of mammals that get them from their diet–the same way that our ancestors did–which wouldn’t include the flax oil.
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Calvin, great comment and I think you’re spot-on. Here’s a question though: what constitutes “middle latitudes”?
Cheers
Scott
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” Ironically, the higher your intake of saturated fat, the more efficient this process is”
This is simply not true, I can’t imagine where you read or heard this. Animal fat, transfat and excessive omega 6 fatty acids inhibits the conversion of ALA into DHA and EPA. Being deficient in certain vitamins and minerals also inhbits conversion of ALA into DHA and EPA. Healthy bodies, contrary to popular belief, convert ALA into DHA and EPA. Some researchers even believe that conversion in many people is as inefficient as it is because the body will not convert more than is needed…
In any event, vegans can still acquire their DHA and EPA from algae. Fish/marine animals themselves do not produce their own DHA/EPA, they acquire it from blue-green algae…
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African, I’m not sure where I read it as I can’t find the source. Wish I could. I’ve actually been reading some interesting stuff on whether EPA and DHA are truly Essential Fatty Acids for humans. Thanks for the insightful comment.
Cheers
Scott
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Scott:
What about walnuts’ omega3 content? I’ve read it’s in ALA. What do you think?
It’s a bit offtopic here, but I would like to take your advice about something. I’ve started olympic weightlifting and I’d like to increase my overall calorie intake, mostly from fat sources. It would be convenient to drink couple shots of oil a day for this but I’m not sure which source would I choose. 60-80 ml of olive oil would be too much? Should I worry about too much PUFA and wrong o6-o3 ratio? I eat lots of (fatty) meat, eggs, veggies and fruits for carbohydrate ( about 150 gramm cho), but it’s hard to reach to the point I’m starting to gain weight especially without nuts. So far I’ve eaten about 5-8 ounce of almonds for the calories but I think my digestion can’t take this amount of nuts.
I would appreciate your answer, thanks!
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Good info Scott. Glad I found this info. I’m a carnivore, and do welcome efficient health advice. The cost of healthy living… is ridiculous if you follow every glam trend. Sorting through the facts, fiction, and the truth are all equally challenging and daunting tasks. I ingest about 6 grams of Fish Oil daily (small fish not salmon or cod), I use flax, but do not see great benefits from it. I have actually found I function better with large portions of fish, beef, and chicken daily. The rest is room created with alcohol and potatoes (irish background).
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Les, walnuts are also an ALA source. Outside of animal foods, I don’t know where you’ll find any EPA or DHA. As for gaining weight, shooting olive oil sounds pretty harsh, though I’m sure it would work to add calories…120 calories per tablespoon. Have you added starchier vegetables like sweet potatoes and squashes? I can load a sweet potato up with tons of coconut cream and oil and some honey and eat it all with no problem…lots of good carbs and saturated fats in there.
And yes, nuts can be harsh on the digestion unless you soak them first. More about that here
JD, lots of people find that more meat = better functioning. I think as long as people stick to unprocessed foods, they tend to find the right amount of meat, green leafies, fruit, etc without having to worry about counting carbs, fat grams or calories.
Cheers
Scott
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Thanks, Scott. I’m glad I found this article; it has helped my re-evaluate my (scrupulously-researched) dietary planning in a big way… I have been a believer in paleo-diet style nutrition for a few years now and I’m finding that the more I learn about it, the more sense it makes (both to my brain and body).
Always love the blog! Thanks again!
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Here’s a link that mentions the relationship between saturated fat and omega-3. Sorry to come late to the discussion.
http://www.westonaprice.org/Saturated-Fats-and-the-Kidneys.html
It can be argued that they’re not a neutral source but Mary Enig, PhD has been studying this stuff since at least the 1950s and was sounding the alarm against trans fats back then, so maybe people should listen to her. She’s written books on the subject of dietary fats.
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