The review contains data from more than 800,000 participants and over 20,000 cases of breast cancer – finding that women with the highest intake of omega-3 PUFAs from marine sources were found to have a 14% reduction in risk of breast cancer compared with women with the lowest intake.
Writing in the British Medical Journal (BMJ), Professor Duo Li and his team from Zhejiang University, China, found a dose-response relationship that showed a 5% lower risk of breast cancer per 0.1g/day or 0.1% energy/day increment of dietary marine omega-3 PUFAs.
“In this meta-analysis dietary intake of marine omega-3 polyunsaturated fatty acids (PUFA), but not alpha linolenic acid (ALA), was associated with a lower risk of breast cancer,” the team concluded – noting that their work “provides solid and robust evidence that marine omega-3 PUFA are inversely associated with risk of breast cancer.”
“Our findings have important public health implications,” said Li and colleagues. “The prevention of breast cancer continues to be an important public health issue for researchers, especially with regard to the investigation of relations between breast cancer, diet, and lifestyle.”
The Chinese team set out to investigate the association between fish and omega-3 PUFA intake and the risk of breast cancer – analysis included data from 26 publications, including 20,905 cases of breast cancer in five studies and 883,585 participants from 21 independent prospective cohort studies from the United States, Europe and Asia.
The team found that marine omega-3 PUFA was associated with a 14% reduction of breast cancer between the highest and lowest category of intake. However, no significant protective association was found for ALA - the plant based omega-3 PUFA.
Further analysis indicated a dose response: each 0.1 g per day or 0.1% energy per day increment of intake was associated with a 5% reduction in risk
Li and his team said that the finding, together with previous publications, “supports a protective role of marine omega-3 PUFA on the incidence of breast cancer."
Published online ahead of print, doi: 10.1136/bmj.f3706
“Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies”
Authors: Ju-Sheng Zheng, Xiao-Jie Hu, Yi-Min Zhao, Jing Yang, Duo Li