Erythrocyte ω-3 polyunsaturated fatty acids are inversely associated with the risk of oral cancer: a case-control study.

Adverse but non-linear associations were observed between erythrocyte EPA, DHA, ω-3 index, and oral cancer risk. Additionally, there were multiplicative interactions between ω-3 PUFAs and other behavior factors such as smoking and drinking. The protective effect of ω-3 PUFAs maybe more significant in the non-smoking or non-drinking population.