Several lines of research suggest that omega-3 fatty acids—particularly DHA—may be linked with modest improvements in blood pressure regulation.
A double-blind, placebo-controlled study published in the Journal of Nutrition (April 2007; 137(4): 973–978) examined the effects of a relatively small dose of DHA (docosahexaenoic acid) on blood pressure. In this crossover study, 38 male subjects were randomized to receive either 700 mcg of DHA per day or a placebo for three months. After a four-month washout period, the groups were reversed.
When taking DHA, subjects experienced an average reduction in diastolic blood pressure of 3.3 mm Hg. Heart rate was also modestly lower in the DHA group, by an average of 2.1 beats per minute.
Observational data point in a similar direction. A large cross-sectional epidemiological study published in Hypertension (2007; 50: 313–319) evaluated blood pressure in 4,680 participants, with measurements taken eight times across four physician visits. The researchers identified an inverse relationship between dietary omega-3 fatty acid intake and blood pressure, meaning higher omega-3 consumption from food was associated with lower blood pressure readings.
Earlier findings are consistent with these results. A meta-analysis published in the Archives of Internal Medicine (June 28, 1993; 153: 1429–1438) reviewed multiple trials examining fish-oil supplementation and blood pressure. Across 11 studies involving individuals with normal blood pressure, omega-3 fatty acids were associated with reductions in blood pressure. An additional six studies involving people with hypertension also showed reductions, with the largest effects observed in individuals starting with the highest blood pressure levels.
Taken together, these findings suggest that omega-3 fatty acids may play a supportive role in cardiovascular regulation, particularly as part of broader dietary and lifestyle patterns.
