Association of ω-3 and ω-6 polyunsaturated fatty acids with tumors: a scoping review

ω-3 polyunsaturated fatty acids (PUFAs) and ω-6 PUFAs are two types of essential PUFAs that must be obtained from food. They are metabolized by the same enzyme system to produce different cytokines, performing different functions. Previous studies have suggested that ω-3 PUFAs have anti-inflammatory, while ω-6 PUFAs have the pro-inflammatory effect on humans. However, there is growing recognition that this view may be too simple. Using tumor as an example, numerous preclinical studies have found that both ω-3 PUFAs and ω-6 PUFAs are associated with tumors, including tumor metabolism and tumor microenvironment. However, their role in tumors may vary, depending on their relative balance. This is in part because they undergo the same enzymatic metabolism. Notably, the ratio of ω-6/ω-3 PUFAs in the diet affects the anti-inflammatory and anti-tumor effects, and ω-6 PUFAs, although regarded as pro-inflammatory, may also have anti-tumor properties under certain conditions. This scoping review aims to summarize the latest literature regarding the metabolic pathways of ω-3 and ω-6 PUFAs and their relationships with tumors. Such updated information will be helpful to clinical and public health professionals regarding the role of ω-3 and ω-6 PUFAs in the prevention and treatment of tumors.