Omega-3 fatty acids have garnered a lot of positive press over the years. They’ve been said to improve diseases ranging from heart disease to rheumatoid arthritis. However, research published in the Journal of the American Medical Association has challenged the assumptions about this supposed nutrition powerhouse.
Researchers were interested in the effects of omega-3 fatty acids on heart disease related deaths, heart attacks, strokes, and sudden deaths. In this systematic review, published in September, findings from 20 randomized clinical trials evaluating omega-3 fatty-acid supplementation outcomes were pooled. Only studies with at least 1-year follow up made the cut. They found no clear association between increased omega-3 fatty acid intake and improved outcome for heart and stroke related disease and mortality.
Does this mean you can tune out the doctor’s advice to increase cold-water fish consumption?
Maybe. However, there are probably too many questions about the results from this meta-analysis to disobey doctor’s orders just yet.
Are the study’s results true for all omega-3 fatty acids?
It is hard to say. Fatty acids are diverse; they fit into more categories than the well-known saturated, unsaturated, and trans fats. In fact, even the omega-3 fatty acid category can be broken down into smaller categories: ALA, EPA, and DHA. While they share many functions, there are small differences in how each of these omega-3 fatty acids works in the body. Therefore, it is possible that one type of omega-3 fatty acid has no effect on heart diseases and strokes, while another has a significant effect. The study did not look at each variety individually.
Would it make a difference when omega-3 fatty acid therapy began?
There have been many studies to examine the impacts of omega-3 on heart and stroke health. Each study began increasing an individual’s omega-3 fatty acid intake at different times; in some cases before onset of any health issues and, in others, immediately following a heart attack or several years after a stroke. These studies indicate that the sooner the increased consumption begins the bigger impact it has. It’s possible, however, that more decisive conclusions could have been drawn had the JAMA analysis looked at studies in which therapy began at similar stages of health or disease.
Is there a difference between omega-3 fatty acids from food and from supplements?
This certainly is a concern, and the researchers knew this. The systematic review looked at omega-3 intake from foods separately from intake from supplements. It found the same results in each group. In food or pill form, it makes no measurable difference to an individual’s risk of heart disease related deaths, heart attacks, strokes, and sudden deaths.
What about the other diseases and conditions omega-3 fatty acids may benefit?
Omega-3 fatty acids are not just associated with improved heart health. They are important to brain development and learning. There is evidence that increased consumption of these fatty acids may slow the effects of aging on the brain. There have even been studies linking omega-3 intake to reduced pain associated with diseases like rheumatoid arthritis. However, this study did not address these conditions.
Were there enough similarities in the studies to ensure valid results?
Systematic reviews are no stranger to this question. On the one hand, they are useful for pooling results from multiple, equivalent studies. The combination creates a larger sample size, and increases the results’ reliability. However, critics frequently point out that it can be difficult to find studies that are close enough in design and execution to draw meaningful conclusions. This is certainly an area of concern for this review. In some cases, researchers were able to compensate for differences among the studies. However, not all differences can be accounted for and could have contributed to the study’s novel findings.
Questions about the health benefits of omega -3 fatty acids are not new. Countless studies have looked at their effects on heart, brain, and overall health. It may be too soon to discount them completely. However, it is important that future research look into the many concerns raised before a final verdict can be reached. In the meantime, discuss any decisions about omega-3 fatty acid supplements – as with all supplements – with your doctor.
Katie Fesler is a first-year Nutrition Communications student with a personal interest in staying heart healthy.