Unsaturated Fatty Acids and Their Immunomodulatory Properties

SIMPLE SUMMARY: Diet can influence human health in both positive and negative ways. Ω-3 polyunsaturated fatty acids have an overall positive effect on humans. The sources of these fatty acids are primarily plant seeds and fish. Consumption of ω-3 fatty acids reduces inflammation and markers associated with certain diseases. Reduction in inflammation occurs through metabolites of ω-3 fatty acids and biophysical and biochemical changes in plasma membrane properties. In general, a diet high in ω-3 and low in ω-6 fats is considered favorable. This can be achieved by increasing fish and vegetable consumption while reducing animal fats in our diet. ABSTRACT: Oils are an essential part of the human diet and are primarily derived from plant (or sometimes fish) sources. Several of them exhibit anti-inflammatory properties. Specific diets, such as Mediterranean diet, that are high in ω-3 polyunsaturated fatty acids (PUFAs) and ω-9 monounsaturated fatty acids (MUFAs) have even been shown to exert an overall positive impact on human health. One of the most widely used supplements in the developed world is fish oil, which contains high amounts of PUFAs docosahexaenoic and eicosapentaenoic acid. This review is focused on the natural sources of various polyunsaturated and monounsaturated fatty acids in the human diet, and their role as precursor molecules in immune signaling pathways. Consideration is also given to their role in CNS immunity. Recent findings from clinical trials utilizing various fatty acids or diets high in specific fatty acids are reviewed, along with the mechanisms through which fatty acids exert their anti-inflammatory properties. An overall understanding of diversity of polyunsaturated fatty acids and their role in several molecular signaling pathways is useful in formulating diets that reduce inflammation and increase longevity.