Dietary vitamin B intake and the risk of esophageal cancer: a meta-analysis.

BACKGROUND

Several epidemiology studies have explored the association between dietary B vitamins' intake and the risk of esophageal cancer (EC). However, the results remain inconclusive. Thus, we conducted a systematic review with meta-analysis to evaluate such association.

METHODS

Literature retrieval was performed using PubMed (Medline), ScienceDirect, and Cochrane Library electronic databases for all studies published from database inception to December 2017.

RESULTS

The meta-analysis included 19 studies and showed an overall decreased risk of EC (OR=0.77, 95% CI: 0.68-0.87) in association with multivitamin B (ie, B1, B2, B3, B5, B6, B9, and B12) dietary intake. In a subgroup analysis based on vitamin B subclass, B1, B3, B6, and B9 vitamins were associated with decreased EC risk (vitamin B1: OR=0.68, 95% CI: 0.56-0.82; vitamin B3: OR=0.70, 95% CI: 0.53-0.94; vitamin B6: OR=0.64, 95% CI: 0.49-0.83; and vitamin B9: OR=0.69, 95% CI: 0.55-0.86). By contrast, no association was detected between dietary vitamin B2 and vitamin B5 intake and EC risk (vitamin B2: OR=0.86, 95% CI: 0.64-1.16; vitamin B5: OR=0.49, 95% CI: 0.20-1.20), whereas a potential non-linear dose-response association was found between dietary vitamin B12 intake and EC risk. A statistically significant, inverse association was observed for an increase of 100 µg/day in supplemental vitamin B6 and B9 and EC risk (vitamin B6: OR=0.98, 95% CI: 0.98-0.99; vitamin B9: OR= 0.89; 95% CI: 0.86-0.94).

CONCLUSION

These findings support that vitamin B may have an influence on carcinogenesis of the esophagus. Vitamin B1, B3, B6, B9 showed a decreased risk of EC, and vitamin B12 showed an increased risk of EC.