Omega-3s and brain health: what the science really says | Dr. Bill Harris & Prof. Sarah Berry
Author: ZOE
July 24, 2025
Duration: 1:03:53
Omega-3 fatty acids have long been lauded for heart health benefits. Yet, emerging research now points to an even more profound impact, directly on our most complex organ: the brain.
Today, we delve into the critical, often misunderstood, role of omega-3s in cognitive function, mental well-being, and even the prevention of neurodegenerative conditions like dementia.
We are joined by Dr. Bill Harris, a globally recognised authority in omega-3 fatty acid research. Bill is a Professor at the University of South Dakota and has over 300 peer-reviewed publications. His foundational work includes pioneering studies on fish oil in the 1980s and shaping American Heart Association scientific statements.
In this episode, Dr. Harris - along with ZOE's Chief Scientist Professor Sarah Berry - illuminate why most individuals may be operating with suboptimal omega-3 levels, and the tangible implications this has for mood regulation, anxiety, and long-term brain resilience. We navigate nuances between omega-3 types like EPA and DHA, debunk common misconceptions surrounding plant-based sources and mercury content in fish, and explore the precise methods for assessing and improving your own "Omega-3 Index."
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Timecodes
00:00 Do Omega 3s Really Protect Your Brain?
01:46 Are We Deficient in Omega 3?
02:15 Plant vs. Fish: Omega 3 Sources Explained
03:34 Are EPA & DHA Really "Essential"?
05:03 The Omega 3 Family Tree: ALA, EPA, and DHA
07:05 Plant Based Myth: Omega 3 Conversion Rates
11:00 The "Optimal" Omega 3 Level: Are You There?
12:51 Historical Omega 3 Intake: What Did Our Ancestors Eat?
14:19 Are Omega 3s Only For Heart Health?
15:13 Why Fish Oil First Made Headlines
18:47 Why Are Omega 3s so Great for Your Heart
21:01 Clearing the Confusion: Omega 3 Supplements for Heart Health
25:11 Omega 3s and Longevity
28:18 Omega 3s and Brain Health: The Latest Science
29:15 Dementia Risk: Omega 3 Levels in the Brain
30:01 Mental Health Breakthrough: Omega 3s for Anxiety & Depression
32:41 EPA vs. DHA for Depression: The Surprising Findings
35:28 The Blood Brain Barrier: Can Omega 3s Reach Your Brain?
38:40 Measuring Your Omega 3 Index: How to Get Tested
42:20 Mercury in Fish: Is it a Real Concern?
45:19 Farmed vs. Wild Salmon: What's the Difference?
48:50 The Omega 6 to Omega 3 Ratio: A Useless Metric?
54:50 Vegan & Vegetarian Options: Algae Based Omega 3s
📚Books by our ZOE Scientists
The Food For Life Cookbook
Every Body Should Know This by Dr Federica Amati
Food For Life by Prof. Tim Spector
Free resources from ZOE
Live Healthier: Top 10 Tips From ZOE Science & Nutrition
Gut Guide - For a Healthier Microbiome in Weeks
Mentioned in today's episode
Associations of plasma omega-3 fatty acid levels and reported fish oil supplement use with depression and anxiety: A cross-sectional analysis from the UK Biobank, 2025
The Association Between Plasma Omega-3 Fatty Acids and Suicidal Ideation/Self-harm in the United Kingdom Biobank, 2025,
Plasma Omega-3 Fatty Acids and Risk for Incident Dementia in the UK Biobank Study: A Closer Look, 2013, NutrientsFish consumption advice is depriving children of neurolipids and other nutrients essential to brain and eye development, 2025, NeuroToxicology
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Episode transcripts are available here.
