Not all healthy fats are created equal

UGA study investigates the role of omega-3 and omega-6 fats in preventing disease and death.

A new study by researchers at the University of Georgia provides even more reason to add omega-3s to your diet.

The study explored the association between omega-3 and omega-6 fatty acids and early death, specifically how an imbalance of these two “healthy” fats impacts risk of early death.

“We found that a higher omega-6 to omega-3 ratio is associated with a greater risk of dying,” said lead study author Yuchen Zhang, doctoral student in the department of epidemiology and biostatistics at UGA’s College of Public Health.

Omega-6 fats are found in nuts, seeds, corn, and soy, so the many byproducts and preservatives derived from these sources mean that people who consume a lot of processed or packaged foods may be getting more of these fats than they realize and driving up their health risk.

“There is some evidence to suggest that the high omega-6 to omega-3 fats ratio typical of Western diets, 20:1 or even higher, compared to an estimated 1:1 during the most of human evolution, contributes to many chronic diseases, including cardiovascular disease, cancer and autoimmune disorders,” said Zhang.

Cancer and cardiovascular disease are the leading causes of death globally. Understanding how the foods we eat can increase or reduce risk of chronic disease is a key area of interest for scientists.

Investigating the imbalance

Zhang and her colleagues analyzed data from over 85,000 participants of the UK Biobank study, a large cohort study that has been ongoing in the United Kingdom since 2006. Participants would complete surveys and provide blood, urine and saliva samples at each assessment.

From these data, the researchers were able to see how varying amounts of omega-6 and omega-3 fats, both individually and the ratios of omega-6 to omega-3s, were associated with early death within 12 years of the initial measurement.

The results show that the balance of omega-3 and omega-6 fats matters. Individuals with a ratio of omega-6 to omega-3 fats closer to 1:1 were less likely to die in the years following the baseline assessment.

“While many previous studies have examined total or individual omega-3 and omega-6 fatty acids, fewer investigated the role of their imbalance in mortality,” said Zhang.

Does that mean people should avoid omega-6s entirely? Maybe not, said co-author Kaixiong (Calvin) Ye, an assistant professor of genetics at UGA’s Franklin College of Arts and Sciences.

“You want to keep that ratio lower, but the thing is that when we break apart those two components and we do a separate analysis, both are good,” he said, “But we do see that when we’re comparing omega-3 and omega-6 by themselves, omega-3 tends to have a stronger protective effect.”

The lesson is about too much of a good thing, he said. Eating more omega-6s than needed suppresses omega-3s, he said.

So, bottom line for individuals, say the researchers: eat more omega-3s, especially if you can get them from seafood.

This work may help answer remaining questions about the complex role of unsaturated fats in lowering risk of death from heart disease and cancer in the Western diet, but more study is needed to confirm the study findings.

Large population-based cohorts such as the UK Biobank study are invaluable assets for public health researchers, said co-author Ye Shen, a UGA associate professor epidemiology and biostatistics.

“The UK Biobank provides unprecedented opportunities to explore a wide array of important research questions, particularly those that require large sample sizes to ensure statistical validity and robustness,” he said.

The study is available online here:

Posted April 24, 2024.