Basil is a very good source of beta-carotene, lutein, ursolic acid and vitamin K. Basil also contains numerous volatile compounds with powerful antioxidant, anti-inflammatory, antimicrobial, and antifungal properties. Basil may help alleviate type 2 diabetes by improving insulin activity in the body. Carnosol, a component of basil, has been shown to inhibit carcinogenesis of human prostate cancer cells. While the evidence is mixed as to whether basil can retard liver tumor formation in experimental mice, it has been shown to inhibit liver cancer metastasis. Basil leaf extract has been found to be highly effective in inhibiting carcinogen-induced lung tumor incidence in experimental mice.
Basil oil and its components have been shown to have significant anti-proliferative activity in the mouse leukemia and kidney cells. In addition, basil oil has been found to significantly inhibit carcinogen-induced squamous cell carcinoma in the stomachs of experimental mice.
Breast cancer-related effects of eating basil
Basil is an excellent dietary source of the carotenoid lutein. Lutein consumption and circulating lutein levels have been found to be associated with reduced risk of breast cancer in several epidemiological studies. Lutein has been shown to inhibit the progression of both ER+ and ER+ breast cancer cells under hypoxia, a low-oxygen condition in which solid breast tumors can thrive. Lutein has also been shown to potentiate the effect of taxane chemotherapy drugs (Taxol and Taxotere) in breast cancer cells.
Linalool, another component of basil, has been found to increase Adriamycin (doxorubicin) induced cytotoxicity and pro-apoptotic effects in chemotherapy-resistant breast cancer cell lines.
While they are closely related, basil (Ocimum basilicum), otherwise known as sweet basil, is not the same plant as holy basil (Ocimum sanctum). Fresh or dried basil typically is used as a food ingredient, whereas holy basil normally is consumed as a herb in the U.S.
When basil is used as a food ingredient, it is safe, but basil essential oil might cause cancer in extremely large quantities since it contains estragole. Estragole is an organic compound that acts as a rodent carcinogen in large doses. The proportion of estragole in basil oil can be significant. Pesto sauce, which has basil as the primary ingredient, can also have a significant estragole component. Pesto can also contain moderately high levels of copper, which could contribute to angiogenesis and metastasis of breast cancer, especialy in women with inflammatory breast cancer (IBC) or triple negative (ER-/PR-/HER2-) disease. Therefore, we recommend against consuming all but small amounts of basil essential oil and consuming basil pesto infrequently (no more than once or twice per month).
Below are links to recent studies concerning this food. For a more complete list of studies, please click on basil.