Omega-3 lowers inflammation, blood pressure in obese adults

Cardiovascular disease, or CVD,  is a leading cause of death worldwide, and diet strongly influences risk. The American Heart Association recommends reducing saturated fat and increasing polyunsaturated fatty acids, or PUFA, intake, which may cut CVD risk by up to 30%. PUFAs include omega-3 and omega-6, but their direct effects on CVD-related inflammation have not been well compared.

Foods like fish are rich in omega-3 and omega-6 polyunsaturated fatty acids, including eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA.

In a recent study, published in the Journal of Lipid Research, Elise Grytten of Haukeland University Hospital and colleagues compared omega-3, or fish oil, and omega-6, or safflower oil, supplements on CVD risk markers. Participants were overweight adults aged 30–70 with abdominal obesity. They received either omega-3 supplements (rich in eicosapentaenoic, or EPA, and docosahexaenoic, or DHA, acids) or omega-6 supplements (rich in linoleic acid) in randomized seven-week sequences. Omega-3 supplements reduced proinflammatory chemokines such as CCL5 and CCL4, suggesting these anti-inflammatory effects could lower CVD risk. Transcriptomic analysis showed overlapping changes in 75 genes across both groups. However, omega-6s’ anti-inflammatory benefits depended on sufficient omega-3 intake. Furthermore, omega-3 lowered blood pressure in participants without hypertension, while omega-6 increased it. Overall, the findings suggest that high-quality omega-3– and omega-6–rich oils may lower the risk of abdominal obesity and cardiometabolic disease. Also, supplementation of omega-6, in contrast to omega-6, appeared to increase adipose inflammation, with unknown clinical relevance.

Despite limitations — including possible carryover effects, unequal supplement doses and small sample size — the authors believe their findings provide new insight into how PUFAs affect adipose inflammation. In the future, they plan to study how omega-6 alters linoleic acid–derived metabolites.