Around 3g of omega-3 fatty acids taken on a daily basis may be the optimal dose for lowering blood pressure. The corresponding research review was published in the Journal of the American Heart Association.
Omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are commonly found in fish, including salmon, sardines, and trout, and are available in dietary supplements. While they have been linked to lower blood pressure, their optimal dosage has remained unclear.
In the current review, researchers analyzed the results of 71 clinical trials published between 1987 and 2020 that examined the relationship between blood pressure and omega-3 fatty acids DHA and EPA. The studies included almost 5,000 participants ranging from 22 to 86 years old. The participants took supplements for an average of 10 weeks.
In the end, the researchers found that adults who consumed between 2-3g of omega-3 fatty acids had reduced systolic and diastolic blood pressure by an average of 2 mm Hg.
Meanwhile, those with hypertension who consumed 3g of omega-3 fatty acids per day experienced a decrease in systolic blood pressure of an average of 4.5 mm Hg, whereas those with hypertension who consumed 5g of omega-3 fatty acids per day experienced declines of 4mm Hg.
"Most of the studies reported on fish oil supplements rather than on EPA and DHA omega-3's consumed in food, which suggests supplements may be an alternative for those who cannot eat fatty fish such as salmon regularly," said study author Xinzhi Li, M.D., Ph.D., assistant professor and program director of the School of Pharmacy at Macau University of Science and Technology in Macau, China, "Algae supplements with EPA and DHA fatty acids are also an option for people who do not consume fish or other animal products."
The researchers note that while their findings support FDA guidance that EPA and DHA omega-3 fatty acids may reduce the risk for cardiovascular complications, further research is needed before their results could become an ‘authorized health claim’.
They note that limitations to their study include how blood pressure was measured and whether the studies exmoaned omega-3 intake from diet or supplements.