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A Lower Omega-3 Index Increased the Risk of Having Cognitive Impairment

Quick Take

A large population study of older adults in southern Germany found that lower Omega-3 Index levels were linked with a higher likelihood of cognitive impairment. In short: if your red-blood-cell EPA+DHA is low, your brain health risk may be higher as you age.


Why Omega-3s Matter for Your Brain

EPA and DHA (the marine omega-3s) are built into brain cell membranes and help keep neurons flexible and well-signaled. The hippocampus—a region critical for memory and verbal recall—appears especially sensitive to omega-3 status. Higher blood omega-3s have also been associated with larger total brain and hippocampal volumes, a proxy for healthier brain tissue as we age.


The KORA-Age Study at a Glance

  • Who: 720 community-dwelling older adults (mean age ~77) from the long-running KORA-Age cohort in southern Germany

  • What: Omega-3 Index (EPA+DHA as % of RBC fatty acids) measured in 2012 by Omegametrix (lab led by co-inventor of the Omega-3 Index, Dr. Clemens von Schacky)

  • Average Omega-3 Index: 6.4% (older Europeans typically run higher than younger U.S. populations)

  • Cognition Measure: Validated telephone survey assessing orientation, memory, attention/calculation, and language; participants categorized as normal vs. mild cognitive impairment/probable dementia (pooled for analysis)

Omega-3 Groups

  • Low: < 5.7%

  • Intermediate: 5.7–6.8%

  • High: > 6.8%

Note: Cut points were set to balance group sizes for statistical comparisons.


Key Findings

1) Low Omega-3 Index = Higher Odds of Cognitive Problems

  • Low group had 77% higher odds of cognitive impairment vs. others

    • Odds Ratio: 1.77 (95% CI: 1.15–2.73; p=0.009)

    • Adjusted for age, sex, education, metabolic risk factors, depression/anxiety

2) More Impairment in the Lowest Group

  • Impairment prevalence:

    • Low: 29.6%

    • Intermediate: 15.8%

    • High: 20.8%

3) Other Patterns

  • Participants with higher Omega-3 Index tended to be older, better educated, and less anxious. Across all groups, men showed more cognitive impairment than women.


What This Means for You

  • An Omega-3 Index around ~7% was associated with lower risk of functional cognitive decline in this cohort.

  • That’s close to the cardiovascular “green zone” often recommended (8–12%). Hitting that range may deliver dual benefits—for brain and heart.

Important: This was an observational analysis—it shows association, not proof of causation. Cognitive status was based on a phone instrument (useful for large cohorts, but not a clinical diagnosis).


How to Raise Your Omega-3 Index (and Track It)

1) Eat EPA+DHA-Rich Seafood (2–3x/week)

  • Salmon, sardines, herring, mackerel, trout, albacore tuna (mind mercury guidance)

2) Consider a Quality Omega-3 Supplement

  • Look for combined EPA+DHA; typical effective ranges are 1,000–2,000 mg/day, adjusted to your target Index and under your clinician’s guidance

  • Algal DHA is a solid option if you don’t eat fish

3) Test, Adjust, Re-test

  • Use an Omega-3 Index blood spot test to see your baseline

  • Tweak intake and re-check in ~3–4 months (the lifespan of red blood cells)


Bottom Line

In older adults, lower Omega-3 Index levels were linked with higher odds of cognitive impairment. Aim for a higher Omega-3 Index through seafood and/or supplementation—and verify with testing—to support healthy brain aging.