Study finds that omega-6 fatty acids are not shown to raise inflammatory markers in blood levels

A recently published cross-sectional study in Nutrients sought to explore if omega-6 offers anti-inflammatory properties. Study authors note the growing interest in seed oils in our diets, which contain high amounts of linoleic acid (LA), an omega-6 fatty acid.^1,2 It is theorized in the study that Western diets may consist of “too much” LA, and this may be attributed to other diseases.

Researchers utilized data from the Framingham Offspring Study,^1,3 “a landmark longitudinal research initiative that follows the children of participants in the original Framingham Heart Study to investigate genetic and lifestyle factors influencing cardiovascular and metabolic health.” LA and arachidonic acid (AA) levels were analyzed in blood samples from 2700 participants. Researchers investigated whether there is any relationship between LA and AA levels and 10 blood/urine biomarkers for inflammation and oxidative stress.¹

Age, race, sex, smoking, blood lipid levels, blood pressure, body weight, etc., were adjusted as they could be “confounding” factors.¹ Data showed that participants with higher LA levels had lower levels of five of the 10 biomarkers.^1,2 There was no correlation between higher LA levels and higher levels of biomarkers. Regarding AA, higher levels of this omega-6 were connected to lower amounts of four biomarkers and also showed no links to higher levels of inflammation/oxidation.

“These new data show clearly that people who have the highest levels of LA (and AA) in their blood are in a less inflammatory state than people with lower levels. This finding is exactly the opposite of what one would expect if omega-6 fatty acids were ‘pro-inflammatory’ – in fact, they appear to be anti-inflammatory,” explained study investigator William S. Harris, PhD; President Fatty Acid Research Institute; Founder, OmegaQuant Analytics, LLC; and Professor, Department of Internal Medicine, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD.¹

“In the flurry of news stories about the harms of seed oils – the primary sources of LA in the diet – many voices are calling for reducing Americans’ intakes of LA. This is not a science-based recommendation, and this study – in addition to many more – point in precisely the opposite direction: instead of lowering LA intakes, raising intakes appears to be a healthier recommendation,” Dr. Harris continued.¹ “These findings contradict a narrative, not previous research findings. There are many studies in the medical literature that are consistent with our findings here.”

Study authors concluded, “Our community-based study identified small, significant, inverse associations between the RBC LA and AA levels and six major biomarkers of inflammation (three in common: IL-6, ICAM-1, and MCP-1), representing a wide variety of inflammation pathways. Our results suggest that LA is more likely to be anti- than pro-inflammatory, and the present efforts to reduce its intake are ill advised.”²

References

1. New study examining blood levels of omega-6 in thousands of subjects concludes that it does not raise inflammatory markers https://omegaquant.com/new-study-examining-blood-levels-of-omega-6-in-thousands-of-subjects-concludes-that-it-does-not-raise-inflammatory-markers/ (accessed Jul 16, 2025).
2. Lai, H.T.M.; Ryder, N.A.; Tintle, N.L.; Jackson, K.H.; Kris-Etherton, P.M.; Harris, W.S. Red Blood Cell Omega-6 Fatty Acids and Biomarkers of Inflammation in the Framingham Offspring Study. Nutrients 2025, 17, 2076. https://doi.org/10.3390/nu17132076
3. Feinleib, M.; Kannel, W. B.; Garrison, R. J.; McNamara, P. M.; Castelli, W. P. The Framingham Offspring Study. design and preliminary data https://www.sciencedirect.com/science/article/abs/pii/0091743575900377 (accessed Jul 16, 2025).