Monday, March 16, 2009

Question Everything

Question: "Can you tell me why flaxseed oil is so good ?"
Some background information:
  • Polyunsaturated fats come in 2 forms: omega-3 and omega-6 fatty acids.
  • One omega-3 fatty acid is essential (i.e. it can only come from diet) - alpha linoleic acid (ALA).
  • Good sources of ALA include green vegetables, walnuts, soybean oil, canola oil and flaxseed oil.
  • Flaxseed oil is the richest plant source of ALA.
  • Your body converts ALA into longer chain omega-3's, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
  • EPA and DHA also occur naturally in some foods, such as fish.
You have probably heard a lot about the heart-health benefits of omega-3 fatty acids. As mentioned above, ALA is a omega-3 fatty acid, but it is the longer chain omegas (EPA and DHA) that provide the health benefits. And so while flaxseed provides ALA, which is converted into the the longer-chain, omega-3 fatty acids, it would be more efficient to eat sources of EPA and DHA. Why? Because these are the fatty acids most strongly linked to improved cardiovascular health.

Bottom line: If you are a vegan/vegetarian, including plant sources of omega-3's in your diet is essential, and you should eat flaxseed oil and other sources of ALA. BUT, if you do eat fish, you should continue to do so because flaxseed oil (or other sources of ALA) is not a substitute for the omega-3's found in fish. This doesn't mean there are no benefits to adding flaxseed oil to your diet, just don't do it at the expense of eating fish. It is recommended that fish should be consumed twice a week.

7 comments:

  1. Good to know. Boy, there is a lot of misinformation out there. I am surprised to read this. I wonder if you are getting less than two servings of fish a week, is it good to add the supplements?

    ReplyDelete
  2. There is a lot of research going on in this area, but the current evidence does not suggest that ALA itself benefits heart health. In terms of the research, we just don't know if taking a fish oil supplement is going to deliver the same health benefits as eating fish. I take a cod liver oil supplement because I don't eat that much fish. As far as I know, there is no evidence to suggest taking a fish oil supplement is bad for you. BUT I recommend dietary sources as the first line of defense !

    ReplyDelete
  3. This is interesting, as I've read that only 4-8% of ALA is converted to EPA and only 0.8% to DHA. It's a problem for vegetarians like me though, who don't eat fish.

    I'm based in the UK and subscribe to VegSoc magazine. There's a new source of omegas from echium seed oil (I hadn't heard of this before). The conversion to EPA is up to five times more than ALA in flaxseed apparently. I contacted the company who make it and was satisfied that I wanted it to become part of my nutritional regime (an unusual veggie, I'm always training in martial arts so omegas are really important for me). I preferred to buy the product from a veggie site though. Worth a look, I'm happy with it. I'll keep you updated with my progress.

    ReplyDelete
  4. Give me that Filet-o-Fish, Give me that fish!

    Thanks, Dr. Nic. I know I'm supposed to take flax seed oil but now I know WHY. Great stuff.

    I just bought this new product put out by Barleans that is essentially a flax seed smoothie. I'll have to get a proper report on it from you.

    ReplyDelete
  5. I like to use a variety of sources to get my omega 3 sources. I use pharmaceutical-grade fish oils, flaxseed oil and hemp seed oil. These all provide a wide range of omega 3, 6 and 9.

    ReplyDelete
  6. Hi everyone
    Great posts. Keep your eyes open for a follow-up on the health benefits of oil. If anyone wants to contribute to a post on this topic, let me know ! I plan to write something soon.

    ReplyDelete
  7. HI KJ, send me the exact name of the product you are using. Are we talking about flaxseed or flaxseed oil ?

    ReplyDelete