Fish Oil: Supplement or Drug or Worthless?

The usefulness of taking over the counter fish oil supplements and now prescription fish oil medications to prevent cardiovascular disease and events like heart attack and stroke has had poor support from medical experts because previous studies have showed minimal to no benefit.  However in the past two years, we have learned more including who can be helped from fish oil and what kind should be taken.

First, only a certain type of fish oil called “Omega 3” is effective.  It has been used in the past in moderate doses to bring down triglycerides in people who are already taking cholesterol lowering drugs (statins) and has been available over the counter and is now available in higher doses by prescription.  Over the past 2 years three studies have established that in people who have high triglycerides (>150mg%) and are taking Omega 3 along with a cholesterol lowering medications, they achieve lower triglyceride levels and enjoy a reduced chance of heart attack and death from heart disease.  Surprisingly, Omega 3 in these doses (1 gram per day) does not reduce the risk of stroke and has a weaker effect in people who do not have established cardiovascular disease as opposed to someone who has known disease of the arteries of their heart.  However, it is now clear that even if you do not have cardiovascular disease, taking an Omega 3 capsule of 1 gram per day can reduce the risk of death from cardiovascular disease PROVIDED your intake of fish is less than 1.5 servings per week.  If you eat 1.5 servings of fish per week or more, there is NO benefit in taking 1 gram/day of Omega 3.

Interestingly, the average dietary intake of Omega 3 in the United States is only 100mg per day which is 1/5th the recommended minimal daily amount of Omega 3 in an ideal diet and 1/10th the amount in a typical one gram capsule of Omega 3.  In other words, the US diet is quite deficient in Omega 3 or “fish oil”.  The best sources of Omega 3 are oily fish such as salmon, herring, anchovies, sardines and rainbow trout.  White fish such as tilapia have much lower content. And to get the benefit of Omega 3 without taking a pill, at least 1.5 servings of fish per week are required.

Finally, a new prescription Omega 3 drug is available called “Vascepa” which has 4 grams of concentrated fish oil per tablet.  In people already on a statin medication with known cardiovascular disease plus elevated triglycerides, taking 4 grams of this fish oil preparation daily has recently been shown to reduce triglycerides, cardiovascular death, heart attack and stroke by 28% compared to placebo.  But, it would be nearly impossible to take this much Omega 3 in one’s diet.  Accordingly, this new preparation of Omega 3 is likely going to be prescribed for a substantial number of people with known cardiovascular disease and elevated triglycerides who already are taking a statin drug.  Its also reassuring that there are minimal to no side effects with all of these Omega 3 preparations.

In summary fish oil supplements and now concentrated prescription preparations seem to have the ability to reduce the risk of death from cardiovascular disease beyond what the cholesterol lowering (statin) group of medicines can achieve.  Yet, for the standard over the counter Omega 3 supplement (1 gram tablet) the cardiovascular benefit, albeit modest, is seen only if dietary Omega 3 is deficient.  Use of the more concentrated form, Vascepa, should be limited to those with both cardiovascular disease and elevated triglycerides who are already on statin medications.