DairyConsumptionandTotalCancerand Cancer-SpecificMortality:AMeta-Analysis ofProspectiveCohortStudies

Abstract

Theassociationbetweendairyconsumptionandcancermortalityvariesamongstudiesandremainsunclear.Thus,weconductedacomprehensive meta-analysisofprospectivecohortstudiestoexaminetheassociationbetweendairyconsumptionandtotalcancerandcancer-specificmortality. We sought eligible studies in PubMed and Web of Science databases for all publications through March 2021, and pooled RRs and 95% CIs were calculated.Weidentified34prospectivecohortstudiesincluding3,171,186participantsand88,545deaths.Comparedwithlowmilkconsumption, highmilkconsumptionwasassociatedwithhighercancermortalityinfemales(RR:1.10;95%CI:1.01,1.21)andpeopleconsuminghigh/whole-fat milk(fatcontent≥3.5%)(RR:1.17;95%CI:1.07,1.28).Increasedrisksofcancer-specificmortalityweredetectedforliver(RR:1.13;95%CI:1.02,1.26), ovarian(RR:1.32;95%CI:1.13,1.55),andprostate(RR:1.23;95%CI:1.02,1.48)cancers.Also,femaleswithhighconsumptionoffermentedmilkhad alowercancermortalityrisk(RR:0.85;95%CI:0.77,0.94).Highcheeseconsumptionwasnotassociatedwithtotalcancermortalitybutratherwith higher colorectal cancer mortality (RR: 1.22; 95% CI: 1.02, 1.46). There was no association between butter (RR: 1.06; 95% CI: 0.70, 1.59) or total dairy product consumption (RR: 0.99; 95% CI: 0.95, 1.03) and cancer mortality. Our results imply that high milk consumption, especially high/whole-fat milk,wasassociatedwithhighercancermortality,whereasfermentedmilkconsumptionwasassociatedwithlowercancermortality,andthiswas particularlyevidentinfemales.Consequently,furtherstudiesarewarranted