The Proof with Simon Hill

Seed Oils: Dangerous or Misunderstood? Bill Harris, PhD on the Truth About Omega-6 fats

Mar 25, 2025

Bill Harris, a leading expert on dietary fats and lipid researcher, unpacks the seed oil debate. He clarifies the misconceptions around omega-6 fats, particularly linoleic acid, and its link to inflammation and heart health. Discussion revolves around the historical rise of seed oil consumption, critiques of past research, and the importance of outcome data in guiding health decisions. Harris emphasizes the biochemical complexity of fats and advocates for a balanced understanding, debunking myths and highlighting the potential benefits of seed oils in a healthy diet.

01:40:01

Episode guests

Bill Harris

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Episode notes

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Quick takeaways

Linoleic acid, found in seed oils, is not harmful and may actually offer cardiovascular health benefits contrary to popular belief.

Research debunks the myth that omega-6 fats, particularly linoleic acid, promote inflammation, suggesting a more complex relationship with health.

There's a need to rethink dietary guidelines that demonize seed oils, emphasizing their beneficial role in a balanced diet for public health.

Deep dives

Understanding Omega-6 and Seed Oils

Linoleic acid, the primary component of omega-6 fatty acids found in seed oils, has become a contentious topic in nutrition. Many health claims suggest that seed oils contribute to inflammation and chronic diseases, yet the scientific evidence does not support these assertions. Research, including studies on biomarker levels, indicates that an adequate intake of linoleic acid is not inherently harmful and may offer cardiovascular benefits. Thus, understanding the role of linoleic acid in the diet is crucial, as it is classified as an essential fatty acid necessary for optimal health.

Intro

2min

The Misunderstanding of Omega-6 Fatty Acids and Seed Oils

3min

From Seed Oils to Beef Tallow: A Dietary Debate

9min

The Truth About Seed Oils

20min

Navigating Dietary Fats: Seed Oils vs Saturated Fats

4min

Dietary Fats: Health Impacts and Choices

8min

Reevaluating Omega-6 Fats

18min

The Omega Debate: Rethinking Fatty Acids for Health

21min

Debunking Seed Oil Myths

11min

10.

Final Thoughts on Seed Oils and Health Insights

3min

Are seed oils actually harmful? Or is this just another wellness myth gone viral?

In this episode, I sit down with Dr. Bill Harris - leading expert on dietary fats - to unpack the science on linoleic acid, an omega-6 fat found in nuts, seeds, and vegetable oils.

We explore the rise of seed oil fear-mongering, the truth about inflammation, cholesterol, oxidation, and why outcome data—not mechanisms—should guide our thinking.

Omega-6 Fats and Health Overview (00:00)
Why the Review Was Updated (01:22)
What Is Linoleic Acid? (06:47)
Linoleic Intake Over Time & Health Links (12:45)
Research Methods and Key Evidence (16:25)
Omega-6 and Inflammation Explained (41:00)
Common Myths About Seed Oils (44:37)
The Oxidation Concern with Seed Oils (49:20)
Omega-6 vs Omega-3: The Real Story (53:39)
Blood Sugar, Insulin & Linoleic Acid (01:03:48)
Heart Health and Linoleic Benefits (01:05:44)
Cancer Risk and Seed Oils (01:13:49)
Public Health and Future Research (01:16:55)
How to Use Vegetable Oils Wisely (01:25:17)
Wrap-Up and Takeaway Advice (01:32:22)

If you’ve been confused by the seed oil debate, this one’s for you.

Visit The Proof website for the full show notes and supporting studies.

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Simon Hill, MSc, BSc (Hons)

• Creator of theproof.com

• Host of The Proof with Simon Hill

• Author of The Proof is in the Plants

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