BackgroundAccumulating epidemiological evidence has shown the favorable associations between healthy dietary patterns and risk of glioma, although the results remain inconclusive.ObjectiveWe therefore carried out a systematic review and meta-analysis to summarize the evidence from previous published studies, and to clarify the effects of healthy dietary patterns, typical healthy foods on glioma.MethodsPubMed, Web of Science, CNKI, and Wan fang data were searched from inception up to September 2022 for eligible studies. Two authors independently performed the literature search, study selection, data extraction, and quality assessment. Heterogeneity across studies was estimated using the Cochran’s Q test and I2 statistic. According to heterogeneity, the fixed-effects model or random-effects model was selected to obtain the relative risk (RR) of the merger. Subgroup analysis, sensitivity analysis and publication bias were also used for our analysis.ResultsTwenty-four articles that met the selection criteria, involving 7,278 glioma cases and 2,143,528 participants, were included in our analysis. There was a reduced risk of glioma in the highest compared with the lowest categories of healthy dietary patterns (RR = 0.58; 95% CI: 0.44–0.77; P < 0.0001). Moreover, compared with the lowest intakes, the highest intakes of vegetables (RR = 0.84; 95% CI: 0.73–0.96; P = 0.012) and fruits (RR = 0.85; 95% CI: 0.72–1.00; P = 0.045) significantly reduce the risk of glioma. However, the intakes of fresh fish, nuts, whole grains, and dairy products showed no statistically significant associations with the risk of glioma (P > 0.05).ConclusionFindings from this systematic review and meta-analysis indicate that higher intakes of healthy dietary patterns, vegetables, and fruits are significantly associated with the lower risk of glioma. Further studies, particularly with prospective design, are required to confirm our findings.

The association between alcohol intake and the risk of glioma has been widely studied, but these results have yielded conflicting findings. Therefore, we conducted this systematic review and updated meta-analysis to systematically evaluate the association between alcohol intake and the risk of glioma. A systematic literature search of relevant articles published in PubMed, Web of Science, CNKI and Wan fang databases up to December 2021 was conducted. Pooled estimated of relative risk(RR) and 95% confidence interval(CI) were calculated using fixed-effects models. A total of eight articles with three case-control studies involving 2706 glioma cases and 2189927 participants were included in this meta-analysis.A reduced risk of glioma was shown for the low-moderate alcohol drinking versus non-drinking(RR=0.87; 95%CI: 0.78, 0.97; P=0.014). In addition, there was no evidence of an increased risk of glioma in the heavy alcohol drinking compared with non-drinking (RR=0.89; 95%CI: 0.67, 1.18; P=0.404). The findings suggest an inverse association between low-moderate alcohol drinking and the risk of glioma, in the absence, however, of a dose-response relationship. More prospective studies are needed to provide further insight into the association between alcohol drinking and glioma risk.