Capsaicin intake and oral carcinogenesis: A systematic review

Chili is the most heavily and frequently consumed spice, either as a flavouring or colouring agent, and it is also a major source of pro-vitamin A, vitamin E and C. The main capsinoidcapsaicinoid found in chili peppers is capsaicin. It has been demonstrated that capsaicin acts as a cancer-suppressing agent through its antioxidant and anti-inflammatory effects, by blocking several signal transduction pathways. Oral squamous cell carcinoma is one of the most prevalent cancer worldwide. It is noteworthy that in countries where populations of diverse ethnic groups co-exist, differences have been observed in terms of incidence of oral cancer. The variances in their diet could explain, at least in part, these differences. The objective of this systematic review is to explore if there is evidence of a possible relationship between capsaicin intake and the incidence of oral squamous cell carcinoma, and discuss such association.

A bibliographical search was made in PubMed, Scopus and Web of Science databases, and finally 7 experimental studies were included; OHAT risk of bias tool was used to assess their quality.

allAll the studies confirm that capsaicin is a chemopreventive agent that prevents the development of oral cancer, through inhibition of malignant cell proliferation and increase of apoptosis.

More human studies are needed in order to clarify the real link between consumption of chili (capsaicin) and the prevalence of oral cancer.