Association between dietary intake of Trans fatty acids and breast cancer risk: a systematic review and meta-analysis

Introduction: Earlier studies have shown that dietary intake of Trans fatty acids are associated with breast cancer risk; however, findings in this regard were conflicting. Aim: To systematically review the current evidence on the association of Trans fatty acids intake with breast cancer and to perform a meta-analysis in this regard to summarize earlier findings.Methods: The online databases of PubMed, ISI Web of Science, Scopus, ProQuest, Science Direct and Embase were searched until November 2017 for related publications using relevant keywords. In total, 7 prospective studies [6 cohort studies and one nested case-control study] with total sample size of 283015 participants were included in this systematic review and meta-analysis. Results: Individuals were aged between 26 to 80 years old. Combining 8 effect sizes from 5 prospective studies and 1 nested case-control study revealed no significant relationship between dietary intake of total trans fatty acids and risk of breast cancer (pooled effect size: 1.02, 95% CI: 0.95-1.10). According to subgroup analysis on prospective studies, we found a significant positive association between dietary intake of total trans fatty acids and risk of breast cancer for studies with follow up duration of 10 years or under (pooled effect size: 1.28, 95% CI:1.02-1.62). In addition, we found no significant association between dietary intake of CLA and risk of breast cancer (pooled effect size: 1.05, 95% CI: 0.95-1.17).Conclusion: We found that dietary intake of Trans fatty acids was not associated with breast cancer risk. Further studies are required to examine the association between dietary intake of other fatty acids and breast cancer.

Keywords:

Fatty Acids , Trans fat , CLA , breast cancer , meta-analysis