Researchers Conduct Omega-3 Index Analysis in NHANES Participants for the First Time

A study published in Current Developments in Nutrition reports the first nationally representative Omega-3 Index data from the Centers for Disease Control and Prevention (CDC)’s National Health and Nutrition Examination Survey (NHANES), revealing that most Americans have low omega-3 levels well below those associated with optimal cardiovascular health.

The study analyzed blood samples from more than 7,200 Americans aged 6 years or older, collected between 2021 and 2023.

According to the results, 54% of Americans had an Omega-3 Index below 4%, a level considered undesirable, and almost 98% of Americans had an omega-3 below the optimal target of 8%. The average U.S. Omega-3 Index was 4.12%, placing the population near the lower end of the intermediate range.

There were other notable trends within the data. Omega-3 Index values increased with age across the whole population. Adults who used omega-3 supplements had significantly higher Omega-3 Index values. Smoking and obesity, on the other hand, were each independently associated with lower omega-3 levels.

This study marks the first time that NHANES has included direct measurement of omega-3 status using red blood cell membrane measurements. Until now, national surveillance has relied primarily on dietary intake estimates rather than objective biomarkers.

“This is a major milestone for omega-3 research and public health,” said Bill Harris, PhD, co-inventor of the Omega-3 Index and founder of OmegaQuant. “For the first time, we have nationally representative biomarker data showing where Americans stand. These findings confirm what smaller studies have suggested for years: that the vast majority of Americans are not achieving optimal omega-3 levels.”
 

Unlike dietary questionnaires, the Omega-3 Index reflects how much of the nutrient has actually been incorporated into the body’s tissues, making red blood cell fatty acid measurements a preferred method for assessing long-term omega-3 status.

According to Harris, the study serves as baseline data for the U.S. population to inform public health strategies, nutrition policy, and future research on fatty acids in population health and disease prevention.

“This study reinforces the value of measuring omega-3 status rather than estimating it from diet alone,” Harris said. “Knowing your Omega-3 Index gives clinicians and individuals a practical tool for assessing nutritional status and tracking improvement over time.”