TY - JOUR
T1 - Association between whole grain intake and breast cancer risk
T2 - a systematic review and meta-analysis of observational studies
AU - Xiao, Yunjun
AU - Ke, Yuebin
AU - Wu, Shuang
AU - Huang, Suli
AU - Li, Siguo
AU - Lv, Ziquan
AU - Yeoh, Eng kiong
AU - Lao, Xiangqian
AU - Wong, Samuel
AU - Kim, Jean Hee
AU - Colditz, Graham A.
AU - Tamimi, Rulla M.
AU - Su, Xuefen
N1 - Funding Information:
This study was supported by grants from the National Natural Science Foundation of China (81402672) and Hong Kong Research Grants Council General Research Fund (14113414).
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/9/21
Y1 - 2018/9/21
N2 - Background: 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. Methods: 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. Results: 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 2 = 63.8%, p for heterogeneity = 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 2 = 58.2%, p for heterogeneity = 0.026), but not in the cohort studies (RR, 0.96; 95% CI: 0.82 to 1.14, p = 0.69; I 2 = 66.7%, p for heterogeneity = 0.029). In addition, stratified analysis suggested that sample size could be a potential source of heterogeneity. Conclusions: 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.
AB - Background: 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. Methods: 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. Results: 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 2 = 63.8%, p for heterogeneity = 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 2 = 58.2%, p for heterogeneity = 0.026), but not in the cohort studies (RR, 0.96; 95% CI: 0.82 to 1.14, p = 0.69; I 2 = 66.7%, p for heterogeneity = 0.029). In addition, stratified analysis suggested that sample size could be a potential source of heterogeneity. Conclusions: 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.
KW - Breast cancer
KW - Meta-analysis
KW - Observational studies
KW - Whole grain
UR - http://www.scopus.com/inward/record.url?scp=85053661435&partnerID=8YFLogxK
U2 - 10.1186/s12937-018-0394-2
DO - 10.1186/s12937-018-0394-2
M3 - Article
C2 - 30241536
AN - SCOPUS:85053661435
VL - 17
JO - Nutrition Journal
JF - Nutrition Journal
SN - 1475-2891
IS - 1
M1 - 87
ER -