Low red blood cell (RBC) membrane content of EPA and DHA, i.e., the omega-3 index (O3I), and elevated RBC distribution width (RDW) are risk factors for all-cause mortality. O3I and RDW are related with membrane fluidity and deformability. Our objective was to determine if there is a relationship between O3I and RDW in healthy adults. Subjects without inflammation or anemia, and with values for O3I, RDW, high-sensitivity C-reactive protein (CRP), body mass index (BMI), age and sex were identified (n=25,485) from a clinical laboratory dataset of >45,000 individuals. RDW was inversely associated with O3I before and after (both p<0.00001) adjusting models for sex, age, BMI and CRP. Stratification by sex revealed a sex-O3I interaction with the RDW-O3I slope (p<0.00066) being especially steep in females with O3I [≤]5.6%. In healthy adults of both sexes, the data suggested that an O3I of >5.6% may help maintain normal RBC structural and functional integrity.
Omega-3 Index is Directly Associated with a Healthy Red Blood Cell Distribution Width