Capsaicin and oral cancer Original paper

Oral squamous cell carcinoma is one of the most common cancers worldwide, but its prevalence varies considerably by region and ethnicity. Capsaicin, the molecule responsible for the “spiciness” of peppers, has potent antioxidant and anti-inflammatory properties; could it protect against oral cancer?

This systematic review included 7 studies (3 in vitro, 2 in vivo, and 2 in both) that investigated the possible anticancer properties of capsaicin. The in vitro studies mainly focused on how capsaicin (or synthetic analogues) induces apoptosis in oral cancer cells. The in vivo studies investigated the effects of capsaicin on tumor size and the incidence of oral epithelial dysplasia (a precursor to cancer) and oral cancer in rats.

Capsaicin promotes apoptosis of oral cancer cells in a dose-dependent manner, and approximately 350 µM is enough to increase levels of proapoptotic biomarkers and reduce the abundance of viable cancer cells. Similarly, capsaicin was shown to reduce tumor volume and cancer cell proliferation in mice and rats.

Establishing dose dependency is an important part of supporting a causal relationship, but it’s important to remember that the doses used in cell or animal studies can be very different from the doses required for the same effect in humans. As a result, high-quality human studies are required before we can actually claim that capsaicin can prevent or treat oral cancer in any way.