Association between folate and risk of head and neck cancer This meta-analysis reviewed the results of various studies that researched folate intake and risk of head and neck squamous cell carcinoma (1). Searches were conducted on various medical databases. 9 studies were included in the meta-analysis. The results showed that the pooled odds ratio for assessing the risk of cancer and folate intake in the highest level versus lowest level was 0.505. The linearity model of dose-response analysis indicated that with increased 100 μg/d folate intake, the risk of cancer decreased 4.3% degree. These results indicate that folate is a protective nutrient against carcinogenesis.