Eating fish is held to be good for the heart. There is an inverse correlation between 20 year mortality from heart disease and fish consumption. The positive effects of fish on heart health have been attributed to high levels of EPA and DHA in fish. However, a meta-analysis of 10 trials, which when combined included 77 917 study participants, indicated that supplementation with omega-3 fish oils does not lower cardiovascular risks. There is controversy on the issue. Some studies indicate that fish oils do lower cardiovascular risks.
The website of the National Center for Complementary and Integrative Health states, ‘Research indicates that omega-3 supplements don’t reduce the risk of heart disease. However, people who eat seafood one to four times a week are less likely to die of heart disease.’
Eating fish in then good for the heart but the jury is out on whether fish oil supplements are good for the heart. Frequently when the Mediterranean diet is mentioned olive oil is mentioned but the Mediterranean diet is also high in fish. The Mediterranean diet includes moderate to high levels of fish consumption. The fatty acid compositions of fish in the Mediterranean Sea consisted of 30.10-46.88% saturated fatty acids, Via fish the Mediterranean diet would be high in saturated fats. I am not arguing that all saturated fats are good. However I think there are difficulties in the synthesis of long chain saturated fats.
Olive oil has high levels of oleic acid. Increasing oleic acid levels via increased olive oil consumption can lead to depression. The focus on olive oil in the Mediterranean diet has been extremely unfortunate.