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Ratio of n-3/n-6 PUFAs and risk of breast cancer: a meta-analysis of 274135 adult females from 11 independent prospective studies.

Yang B, Ren XL, Fu YQ, Gao JL, Li D - BMC Cancer (2014)

Bottom Line: USA subjects with higher ratio of n-3/n-6 in serum phospholipids (PL) have a significantly lower risk of BC (pooled RR = 0.62; 95% CI: 0.39, 0.97; I2 = 0.00%; P for metaregression = 0.103; P for a permutation test = 0.100), and per 1/10 increment of ratio in serum PL was associated with 27% reduction of BC risk (pooled RR = 0.73; 95% CI: 0.59, 0.91; P for linear trend = 0.004; P for metaregression = 0.082; P for a permutation test = 0.116).Higher intake ratio of n-3/n-6 PUFAs is associated with lower risk of BC among females, which implies an important evidence for BC prevention and treatment is by increasing dietary intake ratio of n-3/n-6 PUFA.No firm conclusions from USA populations could be obtained, due to the limited numbers of USA studies.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Food Science and Nutrition, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China. duoli@zju.edu.cn.

ABSTRACT

Background: Increased ratio of n-3/n-6 polyunsaturated fatty acids (PUFAs) in diet or serum may have a protective effect on the risk of breast cancer (BC); however, the conclusions from prospective studies are still controversial. The purpose of this study is to ascertain the relationship between intake ratio of n-3/n-6 PUFAs and the risk of BC, and estimate the potential summarized dose-response trend.

Methods: Relevant English-language studies were identified through Cochrane Library, PubMed and EMBASE database till April 2013. Eligible prospective studies reporting the multivariate adjusted risk ratios (RRs) for association of n-3/n-6 PUFAs ratio in diet or serum with BC risk. Data extraction was conducted independently by 2 investigators; disagreements were reconciled by consensus. Study quality was assessed using the Newcastle-Ottawa scale. Study-specific RRs were combined via a random-effects model.

Results: Six prospective nested case-control and 5 cohort studies, involving 8,331 BC events from 274,135 adult females across different countries, were included in present study. Subjects with higher dietary intake ratio of n-3/n-6 PUFAs have a significantly lower risk of BC among study populations (pooled RR = 0.90; 95% CI: 0.82, 0.99), and per 1/10 increment of ratio in diet was associated with a 6% reduction of BC risk (pooled RR = 0.94; 95% CI: 0.90, 0.99; P for linear trend = 0.012). USA subjects with higher ratio of n-3/n-6 in serum phospholipids (PL) have a significantly lower risk of BC (pooled RR = 0.62; 95% CI: 0.39, 0.97; I2 = 0.00%; P for metaregression = 0.103; P for a permutation test = 0.100), and per 1/10 increment of ratio in serum PL was associated with 27% reduction of BC risk (pooled RR = 0.73; 95% CI: 0.59, 0.91; P for linear trend = 0.004; P for metaregression = 0.082; P for a permutation test = 0.116).

Conclusions: Higher intake ratio of n-3/n-6 PUFAs is associated with lower risk of BC among females, which implies an important evidence for BC prevention and treatment is by increasing dietary intake ratio of n-3/n-6 PUFA. No firm conclusions from USA populations could be obtained, due to the limited numbers of USA studies.

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Related in: MedlinePlus

Forest plot of ratio of n-3/n-6 PUFAs in diet or serum PL for the highest vs. lowest. Prospective studies concerning dietary and serum PL ratio of n-3/n-6 PUFAs separately are referred to by first author, year of publication and number of subjects, weighted and ranked according to the inverse of the variance of the logRR estimate. The relative risks (RRs) are represented by the squares (the size is proportional to the weights used in the meta-analysis), and CIs are represented by the error bars. P values for heterogeneity test (I square and Q test) and RR for the highest exposure quantile vs. lowest from individual study were pooled by using random effect model. The diamonds can represent the pooled RR from subtotal risk estimate of dietary or serum PL ratio, according to their corresponding position in the figure.
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Figure 2: Forest plot of ratio of n-3/n-6 PUFAs in diet or serum PL for the highest vs. lowest. Prospective studies concerning dietary and serum PL ratio of n-3/n-6 PUFAs separately are referred to by first author, year of publication and number of subjects, weighted and ranked according to the inverse of the variance of the logRR estimate. The relative risks (RRs) are represented by the squares (the size is proportional to the weights used in the meta-analysis), and CIs are represented by the error bars. P values for heterogeneity test (I square and Q test) and RR for the highest exposure quantile vs. lowest from individual study were pooled by using random effect model. The diamonds can represent the pooled RR from subtotal risk estimate of dietary or serum PL ratio, according to their corresponding position in the figure.

Mentions: We performed a random-effects model meta-analysis for highest quantile compared with lowest (FigureĀ 2). Eleven independent prospective studies reported the association between ratio of n-3/n-6 and risk of breast cancer, involving 8,331 BC events and 274,135 adult females (premenopausal, postmenopausal, or combined) across different countries. Intake ratio of n-3/n-6 PUFA was inversely associated with BC risk for the highest vs. lowest quantile among study populations (pooled RR = 0.90; 95% CI: 0.82, 0.99; I2 = 11.40%; Pheterogeneity = 0.33).


Ratio of n-3/n-6 PUFAs and risk of breast cancer: a meta-analysis of 274135 adult females from 11 independent prospective studies.

Yang B, Ren XL, Fu YQ, Gao JL, Li D - BMC Cancer (2014)

Forest plot of ratio of n-3/n-6 PUFAs in diet or serum PL for the highest vs. lowest. Prospective studies concerning dietary and serum PL ratio of n-3/n-6 PUFAs separately are referred to by first author, year of publication and number of subjects, weighted and ranked according to the inverse of the variance of the logRR estimate. The relative risks (RRs) are represented by the squares (the size is proportional to the weights used in the meta-analysis), and CIs are represented by the error bars. P values for heterogeneity test (I square and Q test) and RR for the highest exposure quantile vs. lowest from individual study were pooled by using random effect model. The diamonds can represent the pooled RR from subtotal risk estimate of dietary or serum PL ratio, according to their corresponding position in the figure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4016587&req=5

Figure 2: Forest plot of ratio of n-3/n-6 PUFAs in diet or serum PL for the highest vs. lowest. Prospective studies concerning dietary and serum PL ratio of n-3/n-6 PUFAs separately are referred to by first author, year of publication and number of subjects, weighted and ranked according to the inverse of the variance of the logRR estimate. The relative risks (RRs) are represented by the squares (the size is proportional to the weights used in the meta-analysis), and CIs are represented by the error bars. P values for heterogeneity test (I square and Q test) and RR for the highest exposure quantile vs. lowest from individual study were pooled by using random effect model. The diamonds can represent the pooled RR from subtotal risk estimate of dietary or serum PL ratio, according to their corresponding position in the figure.
Mentions: We performed a random-effects model meta-analysis for highest quantile compared with lowest (FigureĀ 2). Eleven independent prospective studies reported the association between ratio of n-3/n-6 and risk of breast cancer, involving 8,331 BC events and 274,135 adult females (premenopausal, postmenopausal, or combined) across different countries. Intake ratio of n-3/n-6 PUFA was inversely associated with BC risk for the highest vs. lowest quantile among study populations (pooled RR = 0.90; 95% CI: 0.82, 0.99; I2 = 11.40%; Pheterogeneity = 0.33).

Bottom Line: USA subjects with higher ratio of n-3/n-6 in serum phospholipids (PL) have a significantly lower risk of BC (pooled RR = 0.62; 95% CI: 0.39, 0.97; I2 = 0.00%; P for metaregression = 0.103; P for a permutation test = 0.100), and per 1/10 increment of ratio in serum PL was associated with 27% reduction of BC risk (pooled RR = 0.73; 95% CI: 0.59, 0.91; P for linear trend = 0.004; P for metaregression = 0.082; P for a permutation test = 0.116).Higher intake ratio of n-3/n-6 PUFAs is associated with lower risk of BC among females, which implies an important evidence for BC prevention and treatment is by increasing dietary intake ratio of n-3/n-6 PUFA.No firm conclusions from USA populations could be obtained, due to the limited numbers of USA studies.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Food Science and Nutrition, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China. duoli@zju.edu.cn.

ABSTRACT

Background: Increased ratio of n-3/n-6 polyunsaturated fatty acids (PUFAs) in diet or serum may have a protective effect on the risk of breast cancer (BC); however, the conclusions from prospective studies are still controversial. The purpose of this study is to ascertain the relationship between intake ratio of n-3/n-6 PUFAs and the risk of BC, and estimate the potential summarized dose-response trend.

Methods: Relevant English-language studies were identified through Cochrane Library, PubMed and EMBASE database till April 2013. Eligible prospective studies reporting the multivariate adjusted risk ratios (RRs) for association of n-3/n-6 PUFAs ratio in diet or serum with BC risk. Data extraction was conducted independently by 2 investigators; disagreements were reconciled by consensus. Study quality was assessed using the Newcastle-Ottawa scale. Study-specific RRs were combined via a random-effects model.

Results: Six prospective nested case-control and 5 cohort studies, involving 8,331 BC events from 274,135 adult females across different countries, were included in present study. Subjects with higher dietary intake ratio of n-3/n-6 PUFAs have a significantly lower risk of BC among study populations (pooled RR = 0.90; 95% CI: 0.82, 0.99), and per 1/10 increment of ratio in diet was associated with a 6% reduction of BC risk (pooled RR = 0.94; 95% CI: 0.90, 0.99; P for linear trend = 0.012). USA subjects with higher ratio of n-3/n-6 in serum phospholipids (PL) have a significantly lower risk of BC (pooled RR = 0.62; 95% CI: 0.39, 0.97; I2 = 0.00%; P for metaregression = 0.103; P for a permutation test = 0.100), and per 1/10 increment of ratio in serum PL was associated with 27% reduction of BC risk (pooled RR = 0.73; 95% CI: 0.59, 0.91; P for linear trend = 0.004; P for metaregression = 0.082; P for a permutation test = 0.116).

Conclusions: Higher intake ratio of n-3/n-6 PUFAs is associated with lower risk of BC among females, which implies an important evidence for BC prevention and treatment is by increasing dietary intake ratio of n-3/n-6 PUFA. No firm conclusions from USA populations could be obtained, due to the limited numbers of USA studies.

Show MeSH
Related in: MedlinePlus