A high plasma level of the omega-3 fatty acid docosahexaenoic acid (DHA) was associated with a lower mortality risk from all causes, including cardiovascular disease, cancer and other causes during up to 14.6 years of follow-up, according to a study published on March 6, 2024, in Mayo Clinic Proceedings.¹

“This is the largest ever study to examine the relationship between DHA status and long-term mortality,” authors Evan L. O’Keefe, MD, and colleagues announced. “The findings strengthen the hypothesis that DHA, a marine-sourced omega-3, may support cardiovascular health and lifespan.”

Dr. O’Keefe and his associates analyzed information from participants in the UK Biobank, a database of information from approximately half a million men and women from England, Wales and Scotland. Participants were recruited from 2007 through 2010 and followed through 2021. The current study included 117,702 adults with available plasma measurements of DHA.

During the follow-up period, there were 8,622 deaths. People with plasma DHA levels in the top one-fifth of participants had a 21% lower risk of dying from all causes, cardiovascular disease, cancer or other causes during a median 12.7 years of follow-up compared with participants whose levels were in the lowest fifth. About 47% of people in the top group reported taking fish oil compared with only 18.3% of the people with the lowest DHA levels.

When researchers merged their results with those of a recent meta-analysis of 17 studies that evaluated DHA levels and mortality, the risk of dying during the follow-up period among the highest fifth of DHA concentrations was 17% lower than the least fifth. Risks of mortality from cardiovascular disease, cancer or all other causes were 21%, 19% and 15% lower for those in the top fifth category of plasma DHA levels.