A diet high in Omega-3 fatty acids, present in oily fish such as herring, sardines, mackerel, tuna and salmon helps reduce inflammation throughout the body and has been found to be associated with a low incidence of cardiovascular disease.
Recent clinical studies have supported the claim that regular consumption of fish oils reduce cardiovascular disease although there have also been other studies with less positive results. The current view is that a diet rich in oily fish and Omega-3 fatty acids is a positive step in a strategy to prevent coronary heart disease.
The health benefits of Omega-3 fatty acids were first discovered by studies on the Greenland Inuit Eskimos. The Inuit had an extremely low incidence of heart disease despite consuming a diet very high in fat. The high intake of Omega-3 fatty acids was suggested to be responsible for the low incidence of atherosclerosis and coronary disease.
There are however, some concerns about the level of dangerous pollutants such as mercury, PCB’s and dioxin that effect the waters and in turn the fish.
In 2004 the Food Standards Agency published advice on the recommended minimum and maximum quantities of oily fish to be eaten per week. This advice provided guidance on the beneficial qualities of Omega-3 fatty acids against the potential dangers of toxic pollutants.
The recommendations on maximum consumption of oily fish were 4 portions per week for men, boys and women past childbearing age and up to 2 portions a week for women of childbearing age, including pregnant and breastfeeding women.
The American Heart Association recommends eating fish at least two times per week. It also recommends regular consumption of plant-derived sources of Omega-3 fatty acids, which are present in soybeans, walnuts, canola oil and flaxseed oil.
Flax seeds contain a high proportion of alpha linolenic acid and its oil, linseed oil. This is probably the most widely available botanical source of Omega-3 fatty acids. The addition of flax seeds to the diet of chickens increases the Omega-3 content of the eggs. There is ongoing research to explore the possibility of boosting omega 3 levels in our diet by adding it to the foods that we give to animals. Omega-3 supplementation in food has also become a significant trend in the food business. Global food companies have been launching Omega-3 fortified foods such as bread, pasta, milk and eggs.
Commercially available preparations of highly purified and concentrated Omega-3 fatty acids can be prescribed and taken on a daily basis for prevention of coronary heart disease. Products such as Omacor have been shown to lower levels of triglyceride in the blood. Omacor at a dose of 1 gram per day was shown in the GISSI-Prevenzione clinical trial to reduce risk of heart attacks in people who had already survived one heart attack. Whether this strategy could be usefully rolled out to decrease cardiovascular disease in diabetes patients needs to be established in further clinical trials before the use of these expensive products become widespread in the diabetes community.