Fish oil supplements

Omega-3 Benefits: The Proof is in the Blood

There has been a lot of research about the benefits of consuming omega-3 fats, primarily from fish or fish oil, for brain and heart health. Several studies in recent years have called those benefits into question, with some prominent scientists stating that people should stop taking fish oil supplements. However, two new studies published this year show that omega-3 fats should not be dismissed so lightly.

A study led by Dr. Liana Del Gobbo at the Stanford University School of Medicine examined the question of omega-3 fats and heart attack. This study analyzed data from over 45,000 people from 16 countries over a 10-year period. It differed from many previous studies in that instead of relying on diet recall, it looked at actual blood levels of omega-3 fats. For every standard deviation increase in omega-3 levels, there was a 9% decreased risk of fatal heart attack. This included both fish-derived omega-3s, as well as plant-derived omega-3s (from walnuts, flaxseed, etc.). Important points to note are that these people did not have heart disease at the beginning of the trial period, and they were not taking omega-3 supplements – their source was diet.

Another recent study confirmed the connection between omega-3s and protection against Alzheimer’s disease. Researchers at the University of Southern California examined older adults, and found that low blood levels of DHA (one of the primary omega-3 fats in fish oil) were associated with higher levels of amyloid plaque – the gunk in brain cells that seems to cause Alzheimer’s disease. They caution, of course, that this does not mean that fish oil supplements can prevent or cure Alzheimer’s disease: this study just showed correlation, not causation.

In both studies, the researchers emphasize dietary sources of omega-3 fats rather than supplementation. While I agree with this approach in general, I feel that fish oil supplementation can fill in the gap when we are not getting the recommended 2-3 servings of cold water fish per week. These studies differed from previous studies that used fish oil supplements like drugs – comparing them to placebo over a relatively brief period of time, often in patients who were already sick. This latest research shows that when it comes to omega-3s, prevention is the best bet. Start eating fish or taking fish oil regularly in your 20s and 30s, rather than waiting to rely on it in your 60s or 70s after the first heart attack.


  • Del Gobbo LC, Imamura F, Aslibekyan S, et al. ω-3 polyunsaturated fatty acid biomarkers and coronary heart disease: Pooling project of 19 cohort studies. JAMA Intern Med 2016; DOI:10.1001/JAMAINTERNMED.2016.2925.Abstract
  • AMA Neurol. Published online August 8, 2016. Abstract  Editorial

Leave a Comment