Conducted by researchers from leading institutions across Australia, Canada, Denmark, Finland, Germany, Iceland, India, Italy, Japan, the Netherlands, Spain, Sweden, Taiwan, the United Kingdom and the United States, the expansive investigation analyzed more than 183,000 subjects across 29 prospective studies.
“This paper confirms previous studies that found favorable relationships between omega-3 and stroke risk by including a very large number of subjects from a wide range of countries,” said William Harris, PhD, president of the Fatty Acid Research Institute (FARI) and one of the authors on the study. “It also gives comfort by showing that raising your omega-3 levels into the healthy zone (~8% Omega-3 Index) you do not increase your risk for clinically significant bleeding.”
One in four odds
According to the World Stroke Organization, one in four adults will suffer a stroke in their lifetime, representing a 50% increase in incidence over the last 20 years and the second leading cause of death worldwide after heart disease.
A paper published in The Lancet last October projects that the treatment, rehabilitation and indirect costs of stroke could more than double from $891 billion in 2020 to $2.3 trillion in 2050.
Through a pooled and harmonized analysis of the 183,291 participants in the current study, the researchers identified 10,561 total strokes, 8,220 ischemic strokes and 1,142 hemorrhagic strokes recorded over a median of 14.3 years follow-up.
When they investigated the associations between circulating and tissue omega-3 polyunsaturated fatty acids, they found that subjects in the highest 20% of omega-3 levels had a 17% lower risk for total stroke compared to those in the lowest 20% of omega-3 levels, with similar results reported for ischemic strokes. Neither EPA nor DPA was associated with a risk for hemorrhagic stroke.
Regarding the suspected mechanism of action, Dr. Harris told NutraIngredients-USA that the simplest explanation is probably via thinning of the blood, much like low dose aspirin, and that other contributing causes would be lowering blood triglycerides and a generalized anti-inflammatory action.
‘Nothing short of exciting’
Commenting independently on the findings, Harry Rice, PhD, vice president of regulatory and scientific affairs at the Global Organization for EPA and DHA Omega-3s (GOED) noted the publication included an “all-star line-up of scientists and/or doctors” who provided strong corroborating evidence to support the benefits of EPA and DHA.
“Given that every 40 seconds, someone in the United States has a stroke, that EPA, DHA and EPA+DHA significantly decreased total and ischemic stroke, is nothing short of exciting and provides yet more compelling evidence for everyone to make certain they are getting enough EPA/DHA in their diet through fish intake and/or via supplementation,” he told NutraIngredients-USA.
In terms of future study, Dr. Harris said the obvious next step would be a randomized trial in people at high risk for stroke to see if treatment with EPA + DHA reduces risk.
“Omega-3 Blood Levels and Stroke Risk: A Pooled and Harmonized Analysis of 183 291 Participants From 29 Prospective Studies”
Authors: James H. O’Keefe et al.