Americans spend more than $1 billion a year on fish oil supplements to support heart health, fight inflammation, prevent diseases, and boost mental functioning. But how significant are cardiovascular benefits?
Both supplements and fatty fish (such as salmon, tuna, herring, lake trout and sardines) are rich in two essential omega-3 fatty acids: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Some plants–such as flaxseeds, walnuts, and pumpkin seeds–are good sources of another type of omega-3 fatty acid: alpha-linolenic acid, which the body can convert into DHA and EPA.
Omega-3 fatty acids have a variety of heart-protective effects. The American Heart Association advises eating at least two serving of fish (particularly fatty fish) per week, adding that people with coronary artery disease may not get enough omega-3 through diet alone. Such patients may want to talk to their doctor about supplements. A simple blood test called OmegaCheck™ can help measure the balance of healthy and unhealthy fats in a patient’s diet.
Here are new and recent findings about the health benefits of fish and fish oil.
- Reduced risk for acute coronary syndrome (ACS). A recent meta-analysis of studies involving 408,305 participants, published in American Journal of Medicine, found that those who ate the most fish (four or more servings per week) had the lowest rate of ACS–a medical emergency in which blood flow to the heart is suddenly blocked–compared to those who ate the least. Each additional 100-gram serving of fish per week was linked with a 5 percent drop in risk.
- Better brain health in older women. In a study of 1,111 postmenopausal participants in the Women’s Health Initiative Memory Study, researchers tested the women’s blood levels of marine omega-3 fatty acids, then measured their brain volume by MRI eight years later, when the women’s average age was 78. Those whose omega-3 levels were twice as high at baseline had 0.7 percent larger brain volume, the equivalent of delaying the normal less of brain cells that occurs with aging by one to two years, reported the researchers.
- Lower danger of heart failure. A recent meta-analysis that pooled data from five studies that included 170,231 participants reported that compared to those who rarely or never ate fish, those with higher intake were less likely to suffer heart failure. An increment of 20 grams of fish daily was associated with a 6 percent lower risk of heart failure.
- Protection against stroke. In another meta-analysis, even infrequent fish intake (one to three servings monthly) helped protect against ischemic stroke, compared to people who never ate fish or consumed it less than once a month. The research, published in the journal Stroke, found that people who ate the most fish had a 45 percent lower risk for stroke, compared to those who ate the least.
- Lower triglycerides and reduced risk for dangerous heart arrhythmias. Fish oil has been shown to be so effective at reducing triglycerides that there are now six prescription omega-3 fatty acid formulations approved in the United States. The AHA cautions patients not to take more than 3 grams of omega-3 fatty acids from supplements unless they are under a physician’s care, since high intakes may cause excessive bleeding in some people. The AHA also reports omega-3 fatty acids decrease risk for arrhythmias that can lead to sudden death, modestly reduce blood pressure, and slow the growth of arterial plaque.