Tales of asking for evidence: are chia seeds all they’re cracked up to be?

I’ve mentioned it before, but this summer I got involved with Sense About Science’s Ask for Evidence Campaign. This is a brilliant campaign in which Sense About Science (for some reason they never abbreviate their name to initials) encourages people to ask organisations about dubious ‘scientific’ claims. Ever wondered what on earth Boswelox actually is and whether it can really counteract ‘skin microcontractions’? Ask the company for evidence. See what they say. (In that particular case the UK Advertising Watchdog has already weighed in, but you get the idea.)


Are chia seeds all they’re cracked up to be?

I picked up on a few different claims, the first of which had to do with chia seeds. They are the latest health food craze (well, you know, one of latest – this is an area that moves fast, another health food craze could have gone from magical weight-loss aid to dangerous cancer risk in the time it’s taken me to type this), and come with all manner of interesting claims from stabilising blood sugar levels to having “8 times more Omega 3 than salmon“. The trail led back to AZChia, a company set up by Dr Wayne Coates of the University of Arizona. Although, in Dr Coates defence, many of the more hyperbolic media claims don’t appear to have actually started with him, and his work seems to be rigorous.

There are lots of claims out there in the press, but they most seem to boil down to omega-3 fatty acids. Now, there’s a whole other essay to be written on that topic, but essentially (wait for it) these are essential (boom) fatty acids. That means we need them to maintain good health and although there’s some controversy over exactly what they do and don’t affect, there’s no question they’re vital for a healthy metabolism. However they can’t be made in the body (not from scratch, anyway) so we have to eat them. This is potentially tricky for vegetarians because the main source of omega-3 fatty acids is fish oils. But they do turn up in certain plant foodstuffs, and one such foodstuff is chia seeds. In fact, chia seeds biggest claim is that they are the “richest natural plant source of omega-3 fatty acids“.

But before we go any further with this it’s important to realise that there’s more than one type of omega-3 fatty acid. There is a group of molecules that fall into this category, and some of them are tricker to obtain from certain food sources than others. In particular, there’s something called ALA (α-Linolenic acid), another called EPA (eicosapentaenoic acid) and finally DHA (docosahexaenoic acid – these names just get better and better don’t they?).

The main source of these last two, DHA and EPA, is cold-water oceanic fish, like cod and salmon. Both EPA and DHA are converted into prostaglandins which regulate cell activity. DHA is a structural component of such minor essentials as your brain, retina and skin. Make no mistake, you need these molecules.

ALA is slightly different. ALA is available from plants such as, guess what, chia. And also kiwifruit seeds (bizarrely, these have nearly as much as chia seeds), perilla and flax, otherwise known as linseed. Humans cannot make ALA; we have to eat it. However our bodies can make DHA and EPA from ALA.  So, eat your ALA-packed plants and, in theory, you get the complete set.

But it’s not quite that simple (it never is, is it?)  Yes we can synthesise DHA and EPA from ALA, but only poorly. For adults, it might be less than 1% for DHA, and probably less than 5% for EPA (the numbers are slightly higher, although not much, for babies).

Back to that claim that chia seeds have 8 times more omega-3 than salmon (not, I should stress, a claim actually made by Dr Coates). It is true? Well, 100 g of salmon contains roughly 0.4 g of ALA, whereas 100 g of chia seeds contains more like 18 g. So that’s actually a lot more than 8 times. On the other hand, chia seeds contain no DHA or EPA (fish sources, remember) whereas salmon will give you about 1.4 g and 0.4 g respectively. Chia seeds may contain more omega-3 in total than salmon, but it’s not the good stuff. There’s none of the DHA that’s so important for healthy brain, skin and eyes. You might be able to convert a little bit from the ALA that is there, probably enough to get by (particularly if you’re a vegetarian or a vegan and willing to eat a lot of seeds), but oily fish really is the best source.

What about the claim that chia seeds are the richest plant source of omega-3 fatty acids? I pressed Dr Coates for evidence of this, since it’s a statement he makes on his website, and his response was as follows:

“No one paper is going to say that. You are wanting something that does not exist to my knowledge. You would need to compare hundreds of analyses and papers, determine good analyses from bad, etc. Different harvest cycles, growing locations, varieties, all affect the numbers so impossible to really do it. The statement is based on years of work and knowledge.”

So tricky to prove, but probably true. Possibly.

There is a little more to this story. Chia seeds are often promoted as a whole food, packed full of many nutrients over and above omega-3s. A ‘super-food‘, if you will. They do indeed contain a whole range of nutrients. But Dr Loren Cordain, author of the book The Paleo Dietcontends that chia seeds also contain high levels of phytate.  Phytate is the salt of phytic acid, and is a substance that binds minerals such as calcium, iron, zinc, magnesium and copper, making them unavailable for absorption by the body. As a result, chia seeds are actually quite a poor source of these minerals. And, as with all plants, it’s a similar situation with vitamin B6 – it’s something we absorb far more effectively from animal sources. In short, just because something’s in a plant, doesn’t mean we can make use of it.


If you’re not a vegetarian, stick to your oily fish.

So, in summary, should you be sprinkling chia on your breakfast cereal? Well, it probably won’t do any harm. If you’re a strict vegetarian or vegan they may be worth considering, although they’re probably not worth paying a lot of money for. If you’re a meat eater, you’re almost certainly better off sticking with oily fish – it’s a much better source of the really essential fatty acids.


I also investigated some other claims for Ask for Evidence, one of which was the statement made by Health Journalist Hazel Courteney on national radio that “the average person absorbs into their bloodstream alone about 14 kg of toxins annually through their skin.” There is more to follow on this particular story, and it should appear on the Ask for Evidence page shortly.

There was also something on anti-bac pens which I’ll discuss next time. Watch this space!

56 thoughts on “Tales of asking for evidence: are chia seeds all they’re cracked up to be?

  1. Pingback: More tales of asking for evidence: is there any point to anti-bac ens? | the chronicle flask

  2. A better source of DHA omega-3 for vegetarians–albeit an expensive one–is algal oils. Those oils are the things the fish get their oils from. They are available in supplement form.


  3. Thanks for the fun and easy to read article. Your articles are very well thought out!

    I was using flax seeds in smoothies and recently heard humans receive only a little bit of the benefits from omega3s in plants. Your article broke down everything i wanted to know in detail and saved me a lot of time! You also cite your sources so that I didnt have to browse through all those marketing websites for information i wanted!


    • I have been using chia seeds for about 5 years and found that they do a great job at hormonal balance and reducing inflammation. In addition, we call them happy food because of the way they feed your brain. We use up to 2 tablespoons each day. Try it and see if you don’t feel happier!


  4. Great info! Thanks so much! Saved a ton of reading! I’m anemic, and I just was researching chia seeds because I just bought some new snack bars, and realize that along with nutrients, they contain chia seeds. Do you think if I eat these throughout the day, along with my iron supplements, they’ll block the iron? The tablets are hefty, at 325 mg, (as I said, I’m pretty anemic). Thanks.


    • To be honest, I don’t know. Best to check with a GP or a dietician (dietician not nutritionist; nutritionists are not necessarily qualified). My feeling is that it would be unlikely to cause a problem, as the absorption problem relates to absorbing nutrients from the seeds. I wouldn’t have thought they would affect tablets taken at a different time, but I’m not an expert on this.


      • Thank you so much for your reply. I’ll put it on the list for my GP. 😊 I’ve found there’s much controversy around such a tiny seed. Perhaps I’ll just avoid them? Are they an occasional part of your diet?


      • They absolutely block iron absorption. I was taking iron everyday , i have been iron def anemia for almost my whole life , thought I had it under control , until I started taking chia seeds in a breakfast shake I was making . It stopped all absorption and left me in a very critical place with my anemia. Its best to avoid them if you can. Same with flaxseed.


    • Try taking a teaspoon full of blackstrap molasses, and do your own research on nutrition. Chemists, and most doctors, are required to take very few hours of nutritional education. There are reasons why animal products are consistently among the most unhealthy foods and plants are consistently the most healhty.

      Liked by 1 person

      • I have. Properly qualified dieticians universally recommend a balanced diet. Animal products provide lots of useful nutrients. It’s all about balance and moderation.


  5. When I initially left a comment I appear to have clicked on the -Notify me when new comments are added- checkbox and from now on whenever a comment is added I recieve 4 emails with the exact same comment. There has to be a means you can remove me from that service? Thanks a lot!


  6. I researched your conclusions that ALA does nto have any health benefits, except for when it is synthesized into DHA and EPA.
    I think that your conclusions are wrong. There are sources that say that ALA has health and anti-inflamatory benefits, without being synthesized into DHA and EPA.
    first, your cited article:
    does’t say that ALA doesn’t have health benefits. on the contrary. but it says that DHA and EPA have much more research done on them. so maybe when we will have more ALA research, we will see that it has as much benefits as DHA and EPA.
    In addition, I found these reserches that show the benefits of ALA:

    SO, what’s your opinion ?


    • Where have I concluded that ALA doesn’t have health benefits?

      My point was that DHA and EPA are essential fatty acids, with important health benefits, that all of us need to consume because we can’t synthesise them in our bodies effectively. Chia seeds are a good source of ALA, but not of DHA and EPA, so in my opinion it’s misleading to compare chia to, say, salmon.


    • There is a UK study that shows humans do convert ALA into EPA and DHA just as vegetarian animals do. It also shows that blood levels of vegan and non fish eaters are on par with heavy fish eaters. Heres the link that references the study and a quote.


      Despite having significantly lower intakes of EPA and DHA (from fish or fish oil), blood levels of EPA and DHA in vegans and vegetarians were approximately the same as regular fish eaters.

      The results indicate that the bodies of vegetarians and other non-fish-eaters can respond to a lack of dietary omega-3 EPA and DHA by increasing their ability to make them from omega-3 ALA.

      And as they said, “The implications of this study are that, if conversion of plant-based sources of n-3 PUFAs were … sufficient to maintain health, it could have significant consequences for public health…”


      • Yes, and that work is interesting, and it was a fairly large study which is also a good sign. However, as the article you linked to also says,

        “[the researchers] chose a blood level measure—micromoles per liter—that has not been well-studied as a measure of adequacy. Instead, virtually all clinical researchers use the percent of omega-3s in red blood cell membranes (the “omega-3 index”) when they’re looking for links between omega-3 levels and heart health. Thus, the meaning of someone’s micromoles of omega-3s per liter of blood is unclear when it comes to predicting people’s risk of developing heart disease.”

        And also,

        “it is not clear that the “small” differences they observed wouldn’t be significant to people’s health status over a decade or more.”

        None of this should be taken to mean that plant-based sources of omega fats aren’t useful as part of a healthy diet, because of course they are. However as things stand, this research doesn’t (yet) provide conclusive evidence to disprove the notion that fish and fish oils aren’t the most efficient source of EPA and DHA. Unless you have good reason not to eat oily fish, it’s still probably a very good idea to include it in your diet.


  7. The article was very explicit on the ALA, sources and DHA found best in oily fish, and identified the false claims made with chia seeds. I was using the wrong information for a year, so thank you for giving a detailed account without forcing me to browse through too many marketing sources. The additional research sources on Ala are also helpful. The information in this article reinforces a valid source for ALA and DHA arguments for maintaining a healthy retina (prevention of AMD), building more cells for better neural pathways in the brain, and maintaining a healthy skin. Thank you, and the additional comments listed were similar to mine.

    Kathryn Johnson


  8. Thank you for this great and informative article. Health fads come and go so quickly. Its so important to look at any food source in its entirety – as, like you alluded too, just because a food has a certain nutrient value – unless it can be properly absorbed and assimilated in the body, then it is actually not doing what it is branded or marketed to do. Great to get a through easy to undestAnd down-Lo on Chia! 😊🙏


  9. I am now going to have to go back to my science books as I was taught the following:
    Essential Fatty acids means that we cannot manufacture in the body

    Linoleic Acid (LA) Omega 6 – prostaglandin’s 1 – PG1

    Alpha-linolenic Acid (ALA) Omega 3
    Prostaglandin 3 (PG3)

    Four other fats are conditionally essential
    GLA – Gamma Linolenic Acid
    AA – Arachidonic Acid
    EPA – Eicosapentaenoic Acid
    DHA – Docosahexanoic Acid

    Also, there is a lot of good research suggesting that the ALA may be important partially for the chelating effect.

    I thought the EPA an DHA had to get converted to PG3 whereas the ALA didn’t. Am I confused?


    • Hi, sorry I’m not totally sure I understand what you’re saying? My point in the article was only that chia seeds are not a good source of EPA and DHA, so comparing them to oily fish could be seen as rather misleading.


  10. Hi! I don’t find yet a good source of omega-3 in plant-based diet. This problem makes me nerves as hell, because I’m vegan ..
    How do you think, am I really need to take a supplement (vegan) or there is some food, that can provide me enough DHA?

    p.s: i’m sorry, if I wrote unclear. I’m not a native speaker..



    • I’m vegan too. You can now get vegan algae oil Omega 3 supplements which have EPA and DHA, such as Opti3 in the UK. (The same manufacturer makes a vegan Vitamin D3, which is also quite a new thing.) I’ve been using them for years and notice they make a difference to my periods and my dry eyes.


    • Check out NutritionFacts.org and search for omega-3 or flaxseed. The nutritional studies reviewed indicate that ground flaxseed is the best plant-based source of omega-3 fatty acids as of now.


  11. i was looking at chia seeds as a source of fiber when i found your article, which, made it so easy to figure out what is what about epa, dha and ala and how they work; thanks for that. i don’t know if you have the answer (and i’ll keep searching for answers), but my doc has me taking fish oil supplements for my cholesterol, and i need fiber for my gut issues and chia seems to be chock full of fiber. i’m not much of a fish eater either – working on that. any info on taking these two together; benefits?


  12. I find chia seeds work great for my bowel movements regardless of whatever else is in them and they make me feel full for a lot longer when taken with a meal. I started taking them as a source of soluble fibre to treat diarrhea but I guess I was taking too much.

    I started to have lots of nosebleeds which I had never had before in my life as well as gum bleeds. I would be spitting out blood every time I brushed my teeth or had a tissue full of blood whenever I blew my nose.

    As soon as I scaled back to just a tbsp a day, the bleeding issues went away along with some of the benefits for my bowel movements. You can’t win I guess.


  13. Hi there. This is an interesting article. I was wondering, though, doesn’t the phytates break down after soaking the chia seeds just like it does after soaking and cooking beans?

    If not, I wonder if the health benefits of chia seeds would become greater if they were grown into micro-greens instead of just eating them like a pudding. Your thoughts?


    • I’m not an expert on this, but I believe you’re right, yes: cooking and sprouting will reduce the phytate content and therefore make the nutrients more absorbable. Chia is usually sold to be eaten raw, though.


      • As the earlier commenter mentioned about soaking the seeds : I had read that soaking makes the nutrients more available. I drink my chia seeds with a bit of juice… mostly for the fiber benefits. Looks like I need to find an omega3 supplement as well. Thanks for a non biased, easy to understand article!


  14. I sprinkle one tea spoon on my toast every morning, thinking is good for my skin because I don’t eat much fish, we live in the mountain and its so expensive, and fish oil is very expensive too. Do you think I should stop having them? or it has some benefits for me? great article!


    • Well, as I’ve said before I’m not a dietician! I’m sure chia has some benefits, just maybe not quite the ones you’ve perhaps been led to believe.


  15. Pingback: Vanilla Chia Seed Pudding | slim birdy

  16. Pingback: Vanilla Chia Seed Pudding | Slim birdy

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  18. what happens to the phytates when the chia seeds are soaked overnight? Also, I have noticed that chia seeds are now sold with probiotics added. I would like to see a study that measured the phytates in soaked chia seeds.


    • I don’t know a lot about this, but I believe that soaking them in an acidic solution (water and vinegar, say) can help to break down the phytate. So that might help, yes.


  19. Hi there – do you know whether there’s any evidence for the benefits of chia seed oil on the skin? I’ve been using a new skincare range that I really like, but I’m dubious about the claims of their star product, a chia seed face oil. They say “Chia has the perfect 3:1 ratio of omega 3 to omega 6 essential fatty acids.”, and that “A couple of drops a few times a day sorts out essential fatty acids, minerals, B-vitamins, amino acids, antioxidants and general goodness for your skin.”
    Trying to maintain a healthy level of skepticism here…


    • Hi! I don’t know much (i.e. anything really) about skincare! Dermatology is a complex area. From what I understand, virtually nothing you put on your skin is absorbed to a depth where it will actually have any effect. Moisturisers can produce a temporary plumping effect – which can make wrinkles seem less obvious for a short while – but that’s all. So I think you’re right to be dubious. But on the other hand, if you like it, and your skin seems to respond well to it, and you can afford it, then why not? Unless you have a medically diagnosed skin condition (e.g. psoriasis) I think moisturiser is one of those things, like shampoo, makeup, perfume etc, where it simply comes down to personal preference.

      Liked by 1 person

      • Great, thanks for the response! This pretty much confirms what I have managed to find out so far, which is that you should just go for the cheapest product that you like because nothing really “works”!

        Liked by 1 person

  20. It would be interesting to see if ALA to EPA and DHA conversion can actually work on the very long term. So, we know that if you just bump the ALA intake, you won’t get enough EPA and DHA because the efficiency of conversion is quite low. But then we have many kilograms of body fat and quite large fraction of that would be in the form of ALA if we would get most of our fats in the diet from whole foods like walnuts, chia seeds, flaxseeds, and also leafy vegetables, instead of cooking oils. With many kilograms of ALA in your body, the low conversion rate to EPA and DHA could be enough.

    The reason why one could suspect this should work is because our bodies have evolved under the circumstances where we would not eat a lot of fish and we would not use cooking oils either. Our diets would be similar to that of the Tsimané indians:


    ” Their diet is high in unrefined carbohydrates (72%) with about 14% protein and it is very low in sugar and in fat – also 14%, which amounts to about 38g of fat a day including 11g of saturated fat.”

    Evolution should have led to a robust body design that can cope with fluctuations in the diet that one can expect to happen in Nature. So, it would be strange if it tuned out that we really need to eat fish regularly to meet our demands for EPA and DHA. It’s a priori far more plausible that the problem with getting enough EPA and DHA has to do with unnatural aspects of our modern diet, our use of cooking oils is then a suspects that should be investigated.


    • Yes, it would be interesting – it would require quite a long term study, though. One thing, though, Europeans in particular HAVE historically eaten a lot of fish in their diets. Likewise Asian countries. So humans have evolved with fish and seafood as an integral part of our diet.


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