Dietary patterns and risk of oral and oropharyngeal cancers: A systematic review and meta-analysis.

Systematic evaluation of evidence assessing the role of dietary patterns on oral and oropharyngeal (OOP) cancer risk can provide a better understanding of their relationship. This systematic review of observational studies aimed to integrate the most recent evidence on the relationship between posteriori and priori dietary patterns and risk of development of OOP cancers. Studies were retrieved from Embase, PubMed, and Web of Science, and a total of 22 publications were included in the systematic review, of which 17 were included in the meta-analysis. Summary risk was estimated for highest versus lowest intakes of most common identified food groups and risk of OOP cancers using the random effect, generic inverse variance method. The quality of the included studies was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS) for Case-Control and Cohort studies. As per pooled analysis, consumption of healthy patterns may decrease the risk of OOP cancers by 43 %, and that of western patterns may increase this risk by 62 %. The pooling of data from ten studies analysing priori patterns and OOP cancers shows that the Mediterranean diet and diverse diet reduce the risk of such cancers, and a pro-inflammatory diet escalates the risk. On NOS, 11 studies were good in quality and 11 were moderate. Adopting a diet rich in fruits and vegetables and low intake of snacks and animal fats can potentially reduce the likelihood of developing OOP cancers. Encouraging Mediterranean diet, diverse diet and anti-inflammatory food components would be beneficial in the prevention and control of OOP cancers.