Effects of Dietary n-3 and n-6 Polyunsaturated Fatty Acids in Inflammation and Cancerogenesis

The dietary recommendation encourages reducing saturated fatty acids (SFA) in diet and replacing them with polyunsaturated fatty acids (PUFAs) n-3 (omega-3) and n-6 (omega-6) to decrease the risk of metabolic disturbances. Consequently, excessive n-6 PUFAs content and high n-6/n-3 ratio are found in Western-type diet. The importance of a dietary n-6/n-3 ratio to prevent chronic diseases is linked with anti-inflammatory functions of linolenic acid (ALA, 18:3n-3) and longer-chain n-3 PUFAs. Thus, this review provides an overview of the role of oxylipins derived from n-3 PUFAs and oxylipins formed from n-6 PUFAs on inflammation. Evidence of PUFAs' role in carcinogenesis was also discussed. In vitro studies, animal cancer models and epidemiological studies demonstrate that these two PUFA groups have different effects on the cell growth, proliferation and progression of neoplastic lesions.

Automated summary

It is recommended to reduce saturated fatty acids (SFA) and increase polyunsaturated fatty acids (PUFAs) n-3 and n-6 in the diet to lower the risk of metabolic disorders. Western-type diet often contains excessive n-6 PUFAs and a high n-6/n-3 ratio. Oxylipins derived from n-3 and n-6 PUFAs play a role in inflammation, while PUFAs have varying effects on cell growth, proliferation, and neoplastic lesion progression, as observed in in vitro studies, animal models, and epidemiological studies.