Omega-3 supplements show surprising effects on blood pressure

A 12-week clinical trial found that omega-3 supplements improved certain blood-pressure readings and inflammation-related markers in patients already taking medication, suggesting potential benefits beyond standard treatment.

A new study published in the journal Nutrients suggests that omega-3 supplementation may improve selected inflammatory biomarkers and blood-pressure measures in patients receiving treatment for hypertension and dyslipidemia.

Exploring omega-3 benefits in patients with hypertension and dyslipidemia

Hypertension and dyslipidemia are frequently coexisting health conditions associated with oxidative stress and pro-inflammatory responses, endothelial dysfunction, and altered vascular tone. The coexistence of these cardiometabolic abnormalities can significantly increase the risk of developing cardiovascular and metabolic diseases.

Long-chain omega-3 polyunsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have shown promise as adjuvant therapies to regulate persistent inflammatory and hemodynamic responses in patients receiving treatments for cardiometabolic conditions.

Omega-3 fatty acid supplementation has widely been linked to improvement in blood pressure and blood lipid profile. However, inflammatory, hemodynamic, and vascular effects of these fatty acids have mostly been studied separately, and there is lack of evidence for their synchronized effects in patients receiving treatment for cardiometabolic conditions.

The current study aimed to investigate the effect of EPA and DHA supplementation for 12 weeks on inflammatory biomarkers, blood pressure, and vascular function in patients receiving treatments for hypertension and dyslipidemia.

In this exploratory, randomized, double-blind, placebo-controlled pilot trial, a total of 100 adults were randomly assigned at 1:1 ratio into the intervention and control groups. The intervention group participants received pharmacological-grade omega-3 capsules in addition to usual antihypertensive and lipid-lowering therapies. The control group participants received identical-looking capsules containing medium-chain triglycerides.

Omega-3 reduces selected inflammatory markers and blood-pressure measures

The analysis of inflammatory biomarkers revealed significantly greater reductions in neutrophil-to-lymphocyte ratio and ferritin in the intervention group compared to the control group at 12 weeks. These findings suggest that omega-3 fatty acids may influence selected inflammation-related biomarkers, rather than producing a generalized reduction in systemic inflammation.

The assessment of blood pressure changes indicated significantly greater reductions in daytime systolic blood pressure, nighttime diastolic blood pressure, and central systolic blood pressure in participants who consumed omega-3 fatty acids over the 12-week period.

The assessment of vascular function showed significantly greater reductions in estimated pulse wave velocity in the intervention group at 12 weeks compared to that in the control group. These findings suggest a possible vascular response to omega-3 supplementation, although they do not independently establish improvements in arterial stiffness.

Omega-3 shows selective benefits without significant cholesterol change

The study reveals that omega-3 fatty supplementation for 12 weeks at a dose of two grams per day is associated with significant changes in selected markers of systemic inflammation, blood pressure, and estimated arterial stiffness in patients receiving standard pharmacological treatment for hypertension and dyslipidemia.

The observed reduction in neutrophil-to-lymphocyte ratio is consistent with emerging evidence suggesting that omega-3 fatty acids including EPA and DHA may influence the balance between circulating innate and adaptive immune cells.

The Omega-3 Index, defined as the combined percentage of EPA and DHA among total fatty acids in red blood cell membranes, serves as an objective biomarker of long-term omega-3 status. Although Omega-3 Index was not measured in this study, existing evidence links EPA and DHA supplementation to increased Omega-3 Index and reduced neutrophil-to-lymphocyte ratio.

Despite observed reductions in two inflammatory biomarkers including neutrophil-to-lymphocyte ratio and ferritin, the study did not find any significant between-group difference in C-reactive protein levels.

Previous studies investigating the effect of omega-3 supplementation on inflammatory biomarkers, including C-reactive protein, tumor-necrosis factor-alpha, and interleukin-6, have produced inconsistent results. The involvement of multiple pathways in mediating the anti-inflammatory effects of EPA and DHA may explain why omega-3 supplementation is not associated with a generalized anti-inflammatory response.

Notably, the ambulatory blood pressure monitoring conducted in the study showed significant reductions in daytime systolic and nighttime diastolic blood pressure in the omega-3-supplemented group compared with the control group. In contrast, blood pressure measured at clinics did not show any significant between-group differences in changes over time.

Given that ambulatory monitoring allows automatic 24-hour monitoring of blood pressure while performing normal day-to-day activities and sleep, these findings highlight the significance of additional information provided by 24-hour monitoring. This additional information is particularly crucial in this context, because 24-hour and nighttime blood pressure are strong predictors of adverse cardiovascular outcomes.

Regarding central systolic blood pressure, which reflects the hemodynamic load experienced by the heart and central arteries, the study found a significant reduction in the omega-3 group compared with the control group. However, these measurements were obtained from a limited number of participants, therefore the findings should be regarded as preliminary evidence requiring further validation.

Regarding vascular effect of omega-3 supplementation, the study found a significant reduction in estimated pulse wave velocity, which is consistent with a possible improvement in arterial stiffness. However, the pulse wave velocity was derived from oscillometric pulse-wave analysis, which is not equivalent to directly measured carotid–femoral pulse wave velocity. These findings therefore should not be interpreted as independent evidence of improved arterial stiffness.

Interestingly, omega-3 supplementation was not associated with significant between-group differences in triglycerides, LDL cholesterol, HDL cholesterol, or fasting glucose, suggesting that the observed inflammatory and blood-pressure changes were not accompanied by measurable improvements in these conventional cardiometabolic markers.

Overall, the study findings suggest a selective response to omega-3 fatty acid supplementation across inflammatory, hemodynamic, and vascular domains rather than a uniform anti-inflammatory or cardiovascular effect. However, the exploratory nature of the trial, multiple statistical comparisons without adjustment, and incomplete availability of some measurements limit the certainty of these findings. Adequately powered clinical trials with larger sample size and prospectively specified endpoints are needed for further validation of these findings.

Journal reference:

• Kotliar C. (2026). Effects of Omega-3 Supplementation on Inflammatory Biomarkers and Ambulatory and Central Blood Pressure in Patients Treated for Hypertension and Dyslipidemia: A Randomized, Double-Blind, Placebo-Controlled Trial. Nutrients. DOI: https://doi.org/10.3390/nu18213717. https://www.mdpi.com/2072-6643/18/21/3717