Shenzhen Key Laboratory of Molecular Epidemiology, Shenzhen Center for Disease Control and Prevention, Shenzhen, China.
School of Public Health and Primary Care, Faculty of Medicine, School of Public Health, Prince of Wales Hospital, The Chinese University of Hong Kong, Room 508, Shatin, New Territories, Hong Kong, China.
Nutr J. 2018 Sep 21;17(1):87. doi: 10.1186/s12937-018-0394-2.
Epidemiological studies have found that high whole grain intake may be associated with a reduced risk of breast cancer. However, the evidence has not been consistent. We conducted a meta-analysis to quantitatively assess the association between whole grain intake and breast cancer risk.
Relevant observational studies were identified by searching PubMed, Embase, Cochrane library databases, and Google Scholar through April 2017. Summary relative risk (RR) estimates were calculated using random-effects meta-analysis.
A total of 11 studies, including 4 cohort and 7 case-control studies and involving 131,151 participants and 11,589 breast cancer cases, were included in the current meta-analysis. The pooled RR of breast cancer for those with high versus low whole grain intake was 0.84 (95% confidence interval [CI]: 0.74 to 0.96, p = 0.009; I = 63.8%, p = 0.002). Subgroup analysis by study design found a significant inverse association in the case-control studies (RR: 0.69; 95% CI: 0.56 to 0.87, p = 0.001; I = 58.2%, p = 0.026), but not in the cohort studies (RR, 0.96; 95% CI: 0.82 to 1.14, p = 0.69; I = 66.7%, p for heterogeneity = 0.029). In addition, stratified analysis suggested that sample size could be a potential source of heterogeneity.
Results of the current meta-analysis suggest that high intake of whole grains might be inversely associated with a reduced risk of breast cancer, and the inverse association was only observed in case-control but not cohort studies. More large-scale cohort studies are needed to confirm the inverse association observed.
流行病学研究发现，高谷物摄入量可能与降低乳腺癌风险有关。然而，证据并不一致。我们进行了一项荟萃分析，以定量评估全谷物摄入量与乳腺癌风险之间的关系。
通过检索 PubMed、Embase、Cochrane 图书馆数据库和 2017 年 4 月之前的 Google Scholar，确定相关观察性研究。使用随机效应荟萃分析计算汇总相对风险（RR）估计值。
共有 11 项研究，包括 4 项队列研究和 7 项病例对照研究，涉及 131151 名参与者和 11589 例乳腺癌病例，纳入了本荟萃分析。高谷物摄入量与低谷物摄入量相比，乳腺癌的汇总 RR 为 0.84（95%置信区间[CI]：0.74 至 0.96，p=0.009；I=63.8%，p=0.002）。按研究设计进行的亚组分析显示，病例对照研究中存在显著的负相关关系（RR：0.69；95%CI：0.56 至 0.87，p=0.001；I=58.2%，p=0.026），但在队列研究中无显著相关（RR，0.96；95%CI：0.82 至 1.14，p=0.69；I=66.7%，p 异质性=0.029）。此外，分层分析表明，样本量可能是异质性的一个潜在来源。
本荟萃分析结果表明，大量摄入全谷物可能与降低乳腺癌风险呈负相关，且仅在病例对照研究中观察到这种负相关，而在队列研究中未观察到这种相关性。需要更多的大规模队列研究来证实观察到的负相关关系。
