Dairy product consumption and gastric cancer risk: a meta-analysis.
OBJECTIVE
To investigate whether dairy product consumption is a risk factor for gastric cancer.


METHODS
We searched the PubMed and Web of Science databases for English-language studies on dairy product consumption and gastric cancer risk that were published between October 1980 and September 2013. One author independently extracted data and assessed study quality. Based on the heterogeneity results, we used either the fixed effects model or the random effects model to compute the summary relative risks and 95% confidence intervals (CIs). We also analyzed subgroups according to the study design, geographic region, sex, and whether there were adjustments for confounders (smoking and drinking) with respect to the sources of heterogeneity.


RESULTS
We found 39 studies that were potentially eligible for inclusion in this meta-analysis, including 10 cohort studies and 29 case-control studies. The summary relative risk for gastric cancer, comparing the highest and lowest dairy product consumption categories, was 1.06 (95%CI: 0.95-1.18). Specific analyses for milk, butter, and margarine yielded similar results, but the results for cheese and yogurt were different. There was significant heterogeneity for all studies (Q = 112.61; P = 0.000; I (2) = 67.1%). No publication bias was observed (Egger's test: P = 0.135; Begg's test: P = 0.365). There was a nonsignificant association between dairy product consumption and gastric cancer risk in the subgroup analysis for the study design, sex, geographic region, and whether there were adjustments for confounders (smoking and drinking).


CONCLUSIONS
In our meta-analysis, dairy product consumption was associated with a nonsignificantly increased risk of gastric cancer. However, this result should be verified using large, well-designed prospective studies.
Yan Sun, Lian-Jie Lin, Chang-Qing Zheng, Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110022, Liaoning Province, China.
Yan
Y
Sun
Yan Sun, Lian-Jie Lin, Chang-Qing Zheng, Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110022, Liaoning Province, China.
Lian-Jie
LJ
Lin
Yan Sun, Lian-Jie Lin, Chang-Qing Zheng, Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110022, Liaoning Province, China.
Li-Xuan
LX
Sang
Yan Sun, Lian-Jie Lin, Chang-Qing Zheng, Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110022, Liaoning Province, China.
Cong
C
Dai
Yan Sun, Lian-Jie Lin, Chang-Qing Zheng, Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110022, Liaoning Province, China.
Min
M
Jiang
Yan Sun, Lian-Jie Lin, Chang-Qing Zheng, Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110022, Liaoning Province, China.
Chang-Qing
CQ
Zheng
D003611:Dairy Products / Q000009:adverse effects*; D004032:Diet / Q000009:adverse effects*; D005247:Feeding Behavior; D006801:Humans; D008019:Life Style; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000453:epidemiology*
Dairy product; Gastric cancer; Meta-analysis; Milk