Two recent studies find relationship between omega-3 levels and cell membrane integrity, immunity

Two recent studies published in Prostaglandins, Leukotrienes and Essential Fatty Acids observed benefits associated with higher blood omega-3 levels (EPA and DHA) in healthy people, measured by the Omega-3 Index. The first study¹ found that the Omega-3 Index is directly associated with a healthy red blood cell distribution width (RDW), a measure of cellular integrity. Both these measures are related to membrane fluidity and deformability, or the red blood cell’s ability to change shape. Both low Omega-3 Index levels and elevated RDW are risk factors for all-cause mortality. Researchers found an inverse relationship between Omega-3 Index levels and RDW, meaning that the higher the omega-3 levels, the lower the RDW is. Specifically, in healthy adults of both sexes, an Omega-3 Index of greater than 5.6% may help maintain a normal red blood cell structural and functional integrity.

The second study² investigated the relationship between Omega-3 Index levels and neutrophil-lymphocyte ratio (NLR), which is a biomarker of systemic inflammation that measures innate-adaptive immune system balance. Low Omega-3 Index and elevated NLR are associated with higher risk of chronic disease and mortality. Researchers found that subjects with a higher Omega-3 Index of greater than 6.6% was associated with a lower NLR, while the opposite was true for subjects with an Omega-3 Index of less than 6.6%. This suggests that a higher Omega-3 Index supports a “quiescent, balanced immune system.”

“The NLR paper may be particularly important because most nutrition-immune studies measure circulating levels of inflammatory molecules, i.e., markers of inflammation, making them disease-related findings,” said Michael McBurney, PhD, FCNS-SCN, FASN, a lead author of both papers, and consulting scientist with the Fatty Acid Research Institute, in a press release. He added, “This is a report of an association between nutrient status and immune function/balance based on cells in healthy people.”

“These two reports linking a high Omega-3 Index with low (i.e., healthier) levels of two novel biomarkers — RDW and NLR — help us understand a little better why omega-3 fatty acids are good for us,” said William S. Harris, PhD, FASN, senior author on both studies and President of FARI.

Reference

1. McBurney MI et al. “Omega-3 index is directly associated with a healthy red blood cell distribution width.” Prostaglandins, Leukotrienes and Essential Fatty Acids, vol. 176 (2022)
2. McBurney MI et al. “The omega-3 index is inversely associated with the neutrophil-lymphocyte ratio in adults'” Prostaglandins, Leukotrienes and Essential Fatty Acids, vol. 177 (2022)