Why Does Fish Oil Only Work Some of the Time?

The answer might be your refrigerator…

Approximately one out of every three American adults consume some form of omega-3 oil regularly. The majority is from eating fish, while fish oil pills provide most of the rest. Consumption of fish is advocated by the American Medical Association, American Heart Association, World Health Organization, and almost every other authority aside from those who champion vegetarianism. The vegetarian community admits the need for omega-3 oils, they just prefer to get it from flaxseed or algae.

Bad press for fish

So fish is good. In contrast, the headlines are “Fish oil pills: A $1.2 billion industry built, so far, on empty promises” (Washington Post), “Fish oil sales don’t reflect evidence” (Reuters). The Journal of the American Medical Association, in its most recent review (2012), agreed with the headlines. “Overall, omega-3 PUFA (PolyUnsaturated Fatty Acid) supplementation was not associated with a lower risk of all-cause mortality, cardiac death, sudden death, myocardial infarction, or stroke based on relative and absolute measures of association.”

Good at every age

At the same time, the vast majority of research continues to show significant benefits from fish oil supplementation. The World Health Organization advocates supplementation in pregnancy because of beneficial pregnancy outcomes. As we work our way up the age scale, the Federation of Societies of Experimental Biology journal published research documenting fish oil supplementation improves metabolic syndrome in overweight adolescents. Another study shows interactions between B vitamins and omega-3 fatty acids aided in the prevention of brain atrophy and cognitive decline in early-stage Alzheimer’s.

To translate this into common terms, fish oil supplementation is good for babies, teenagers, and old agers.

Fish oil supplementation is good for babies, teenagers, and old agers. Share on X

Only 1% of studies?

If you’re wondering how the authors in the Journal of the American Medical Association (JAMA) reached their conclusion, they excluded 99% of fish oil studies (they used 20 out of 3680), only focusing on very large randomly controlled trials. The key criteria for any fish oil study is measurement of blood levels and an extended duration of administration — i.e., several years, which unfortunately, neither were used by the JAMA criteria.

With a finer eye, the University of Oregon Linus Pauling Institute, an excellent source for information on micronutrients, sees benefits for neurologic development, cardiovascular protection, prevention of diabetes, Alzheimer’s disease, and macular degeneration, and improvement of schizophrenia. (Full disclosure — I contribute to LPI)

Fish vs fish oil capsules

While there is little disagreement that higher intake of omega-3 oils is beneficial, the studies involving intake from fish show more consistent benefit than intake from capsules. The search for cofactors that are found in fish — such as vitamins and minerals — that would contribute to better outcomes — has not yielded consistent results.

Fresh is best

Some researchers in New Zealand (Albert et. al), however, published a review of fish oil studies that includes a hypothesis that we find quite attractive. As anyone knows, fish oil can spoil, and when it does, in addition to the smell, it loses its antioxidant properties and degenerates into peroxides, which are damaging to cells. As you might suspect, neither the large JAMA studies, nor hardly any of the authors of the other three thousand Omega-3 studies had the bright idea to consider that fish oil can spoil!

Hardly any of the authors of three thousand Omega-3 studies had the bright idea to consider that fish oil can spoil! Share on X

90% are oxidized

The same New Zealand researchers also tested 32 commercial fish oil preparations right off the shelves of pharmacies. Only 3 of 32 passed the standards for oxidation. Cost and manufacture dates were not related to outcome. Country of origin was noted (including the US and Norway), but brand names were omitted. The Council on Responsible Nutrition, an industry group, volunteered a response based on point of manufacture testing, not point of consumption testing.

So what to do?

In this case we have a very low risk recommendation that may have significant benefits. If you can’t keep up an adequate intake of cold water fish — Atlantic mackerel, cod, haddock, herring, mahi mahi, salmon, anchovies, pollock, trout, whitefish, and sardines — then consider supplementing with a fish oil supplement.

If you opt for supplements, check the manufacturer and use-by dates, and buy small bottles — no more than a 30-day supply. Keep it in the refrigerator, where it should be stable for 40 days (or the freezer, where it is stable for about 100 days). Don’t be shocked when checking on manufacture dates and see fish oil for sale after months at room temperature. Know your source. Perhaps one day fish oil will be shipped and stored refrigerated. You can use prescription fish oil, but the cost is considerable.

If you opt for fish oil supplements, check the manufacturer and use-by dates, and buy small bottles, no more than a 30-day supply and keep it in the refrigerator. Share on X

References:

Lipids. 2003 Apr;38(4):415-8.
Dietary intake of fish vs. formulations leads to higher plasma concentrations of n-3 fatty acids.
Visioli F1, Risé P, Barassi MC, Marangoni F, Galli C.

Supplementation and Risk of Major Cardiovascular Disease Events — A Systematic Review and Meta-analysis
Evangelos C. Rizos, MD, PhD; et. al

Oxidation of Marine Omega-3 Supplements and Human Health
Benjamin B. Albert,1 David Cameron-Smith, Paul L. Hofman, and Wayne S. Cutfield

Interactions Between B Vitamins and Omega-3 Fatty Acids in the Prevention of Brain Atrophy and of Cognitive Decline in Early Stage Alzheimer’s David Smith FASEB