2 secondary prevention trials have looked at reducing total and saturated fat intake in people with existing heart disease. Neither study found an effect of reducing total and saturated fat intake on incidence of ischemic heart disease, although these studies were small and lacked statistical power. 6 studies have looked at altering the quality of dietary fat in heart disease patients by increasing the intake of polyunsaturated and monounsaturated fats. Only one of these studies found no effect on rates of nonfatal heart attacks and cardiac deaths. Good sources of polyunsaturated fats include flaxseed oil, canola oil, and safflower oil.
Olive oil is a good source of monounsaturated fats.
Supplementation with omega 3 fatty acids from fish oil can also help reduce heart disease risk.