#569: The History of Fat, Cholesterol & Heart Disease

Listen Here:

For a full list of apps, go here. Or simply search “Sigma Nutrition” in your app of choice.
Or listen directly on the Sigma website here.

Introduction

The idea that saturated fat might be harmful to our health has sparked controversy for decades. In recent years, counter-narratives have surged: suggesting that concerns over saturated fat were overblown, that LDL cholesterol doesn’t matter, or that the original diet-heart hypothesis has been debunked. These claims have become especially popular in online wellness spaces and certain dietary communities, often wrapped in compelling but misleading rhetoric.

So what does the best available evidence actually say? And how should we think about saturated fat, LDL cholesterol, and cardiovascular risk in the current day?

In this wide-ranging interview, originally recorded for the Chasing Clarity podcast, Alan and Danny explore the scientific consensus around saturated fat’s impact on blood lipids, why LDL and apoB are central to atherosclerotic disease, and how dietary patterns can meaningfully reduce risk.

Importantly, they also address some of the most persistent myths and half-truths that fuel confusion, from flawed interpretations of the Seven Countries Study to misrepresentations of newer meta-analyses.

Guests

Dr. Alan Flanagan has a PhD in nutrition from the University of Surrey, where his doctoral research focused on circadian rhythms, feeding, and chrononutrition.

This work was based on human intervention trials. He also has a Masters in Nutritional Medicine from the same institution.

Dr. Flanagan is a regular co-host of Sigma Nutrition Radio. He also produces written content for Sigma Nutrition, as part of his role as Research Communication Officer.

Danny Lennon has a master’s degree (MSc.) in Nutritional Sciences from University College Cork, and he is the founder of Sigma Nutrition.

Danny is currently a member of the Advisory Board of the Sports Nutrition Association, the global regulatory body responsible for the standardisation of best practice in the sports nutrition profession.

Timestamps

• [03:41] How do we know saturated fat impacts LDL-C?
• [05:28] Metabolic ward studies and key findings
• [11:13] The Keys equation and subsequent research
• [17:17] Epidemiology and long-term studies
• [31:48] The Seven Countries Study
• [44:25] Understanding the impact of saturated fat on blood lipids
• [47:23] Historical and research perspectives on saturated fat
• [50:43] Practical dietary strategies for improving blood lipids
• [53:48] The Portfolio Diet and other dietary interventions
• [58:07] The role of pharmacology in managing blood lipids
• [01:00:58] Addressing misconceptions and common claims
• [01:13:57] Key ideas segment (premium-only)

Related Resources

• Join the Sigma email newsletter for free
• Subscribe to Sigma Nutrition Premium
• Enroll in the next cohort of our Applied Nutrition Literacy course

Premium Content

• Detailed study notes
• Transcript

Not a Premium subscriber? Subscribe here!