The review of existing evidence, published in Scientific Reports, identified a potential dose-response relationship between all-cause mortality and both dietary intake of omega-3s and circulating levels of omega-3 long-chain polyunsaturated fatty acids (LCPUFAs).
Led by senior author Li-Qiang Qin from Soochow University, China – and co-authored by Professor Manfred Eggersdorfer ofDSM Nutrition Products – the analysis pooled data from eleven prospective studies involving more than 370,000 participants from the general population.
“In this meta-analysis involving over 30 thousand deaths events from 11 prospective studies, both dietary and circulating omega-3 LCPUFA are shown to be significantly associated with reduced risk of all-cause mortality, and the associations are similar for EPA and DHA,” wrote the team.
However, the team conceded that since the meta-analysis is based on observational studies, there is potential that other influences or unmeasured confounders from the original studies could impact the findings.
“Future well designed primary prevention trials that account for nutrition status, health conditions, and medication usages of participants are also warranted to confirm our findings and those from others,” said the team – who added that larger-scale prospective studies could also help to identify whether the potential dose-response association found in the current meta-analysis is linear or nonlinear.
Li-Qiang Qin and colleagues noted that while there have been a number of prospective observational studies that investigated the relationships between dietary or circulating omega-3 LCPUFA and all-cause mortality, “the results have been inconsistent.”
“In an attempt to quantitatively summarise the evidence, a systematic review and meta-analysis was carried out in the present study,” they said – noting that searches for potentially eligible studies were performed using the PubMed and EMBASE databases, and that after inclusion criteria were applied a total of eleven prospective studies involving 371,965 participants and 31,185 death events were included in the meta-analysis.
Results from the pooled analysis suggested that both dietary and circulating omega-3 LCPUFA are significantly inversely associated with risk of all-cause mortality, said the team.
Further dose-response analysis, revealed that each 0.3 gram per day increment in omega-3 LCPUFA intake was associated with 6% lower risk of all-cause mortality, while each 1% increase in the proportions of circulating EPA and DHA in total fatty acids in blood was associated with 20% and 21% decreased risk of all-cause mortality, respectively.
Source: Scientific Reports
Volume 6, Open Access, Article number: 28165, doi: 10.1038/srep28165
“N-3 long-chain polyunsaturated fatty acids and risk of all-cause mortality among general populations: a meta-analysis”
Authors: Guo-Chong Chen, et al