Wednesday, July 21, 2010

About those Fish Oil Supplements...

How do you know what fish oil supplement is best and how much to take?    

First, let's be clear that we're talking specifically talking about "fish oil".  Often, the two active components of fish oil (EPA and DHA) are referred to as omega-3s or omega-3 fatty acids.  Both EPA and DHA are omega-3s.  In fact, there are a whole bunch of omega-3 fatty acids out there (for example, one called ALA).  But only EPA and DHA have been scientifically proven in multiple studies to benefit your heart and brain.  Supplements from flaxseed or other oils contain other types of omega-3, which are important, but they do not have the same potency or efficacy as EPA and DHA.  

Depending on your health status, you may want to take more or less fish oil.  Experts recommend that healthy persons consume 1-2 fatty fish meals a week to obtain their fish oil, which is equal to about 200-500 mg/day of EPA and DHA.  If you are at risk for heart disease, experts recommend supplementation of a higher dose (up to 3000 mg/day) under the care of a physician.  There's even a prescription formula of fish oil called Lovaza for people with really high blood fat levels (called triglycerides).  On the other hand, if you're taking blood thinners or have other underlying health issues, you may not want to take a fish oil supplement at all.  So think about all that before you read the stuff below.  

If you don't eat 1-2 servings of fatty fish a week or if you just want to know what supplement to take, here are some considerations to pick the right bottle:

1. The source of fish oil.  If you read the bottle, the ingredients may include things like menhaden (a garbage fish), sardines, anchovy, mackerel, cod, algae or krill (sea monkeys...seriously, sea monkeys).  To the best of my knowledge (based on my review of the scientific literature), there are no meaningful differences between the sources of EPA and DHA when consumed at equivalent amounts (unless you're a vegetarian and would prefer to eat algae over a fishie).

2. The amount of EPA and DHA.  This is where you can find some big differences between supplements.  If you are a normal, healthy person, you may want to follow the advice of some experts and take a supplement with about 300 to 500 mg/day of total omega-3 fatty acids from EPA and DHA.  This number will be clearly indicated on the label.  There will also be a number for the total amount of fish oil...disregard that number and focus on the number listed for EPA and DHA.  For example, I have a fish oil supplement from CVS Pharmacy.  It has 1,200 mg of fish oil but all I care about is that it has 360 mg of total omega-3 fatty acids from DHA and EPA.  I would consider this a "good one".  If you take less this level of fish oil, the risk of "fishy burps" and the unpleasant gastrointestinal effects should be low or none.  If you go much higher, you may want to keep your supplement in the freezer, which will reduce the unpleasantries (thanks to Melissa for this tip).

3. The amount of contaminants like mercury and PCBs.  As I indicated in my last post on fish oil, very often the good stuff (EPA and DHA) comes with some bad stuff (mercury, PCBs, PAHs, etc.).  The proper way to eliminate the bad stuff is through processing of the oil.  In March of 2010, a law suit was filed against several manufacturers of omega-3 oils (mainly cod liver oils and shark oils) because they contained pretty high levels of PCBs (and the suit is still pending)...obviously not processed very well.  However, Consumer Reports looked at different fish oil supplements (mostly from menhaden and other fish) and all were very low in the bad stuff.  My CVS Pharmacy fish oil clearly says that it is mercury free and of high purity, so I feel pretty good about it.  Bottom line is that if purity is not clearly indicated on the label, you may want to pass on that one.

4. The price.  Given all of the above, it should be pretty easy to figure out the price-value equation of different supplements.  Until someone gives me a reason otherwise, I'm sticking with my CVS Pharmacy supplements made from anchovy and sardines for the summer...because they are cheap and contain the good stuff without the bad stuff.  In the winter, I take Nature's Bounty Omega-3 + vitamin D just because I'd rather take fewer pills (and we all know how important vitamin D is for health).  But like any science, things could change in the flap of a fin...will update as the science evolves.

Dr T

(Sources used for the information above include the Dietary Guidelines for Americans, Omega 3 Information, Pubmed, and American Heart Association)


  1. Easily digestible science for the rest of us. Thank you!

    Hourrah for fish oil!

  2. My doctor also told me about one at Jewel(he did a ton of research on fish oil)...Equaline Triple Strength Omega 3 Fish Oil. 1400 MG of fish oil 900 mg. of EPA/DHA from anchovies, mackerel and sardines.

  3. This is like some crazy across the world fish esp moment. I just purchased an industrial size bucket of the stuff yesterday. For all you aussies out there, the best one I could find was Blackmores. I still lost my keys today though.

  4. Such a very informative post. I am planning to have fish oil on my diet. That is why I am looking for information about fish oils. This article is what I am looking for.

  5. So I have the same CVS 1200mg fish oil you talked about. The lable says to take 3 a day, but that seems like a lot. I have been taking it twice a day.
    What dosage do you recommend?

  6. Thanks for your comment/question! I just take one capsule the days of the week when I remember (3-4 times/week maybe). Plus I try to eat tuna or salmon at least once a week. This approach is consistent with the major public health recommendations for fish oil intake in healthy persons.

    People at high risk for heart disease or with diagnosed high triglycerides should talk to their doctors about dosage...they may want to take more. Since fish oil could interact with other medications, it's smart to talk to your physician or pharmacist first if you are on any existing medications or have any serious health conditions before taking fish oil supplements.

  7. I no heart issues I am aware of. I started taking it as a suggestion from a trainer at the gym. I was getting some pain in my knees and ankles when jogging.
    I do take Naproxen 500mg twice a day for artritis. Are there any kind of intereactions i should know about? If not is 2 a day a good dosage?

  8. Fish oil supplements are really good for the heart. We should also eat food rich in healthy fats to prevent health problems.

  9. Fish oil contains omega 3 which is essentially good for the heart. It has anti-inflammatory properties which helps maintain the flexibility of the joints and muscles.

    herbal supplements online