In today’s episode Dr Matthew Nagra returns to The Proof to break down a new JAMA Internal Medicine study on butter, plant-based oils, and mortality.

Over 200,000 Americans were followed for 33 years — so what did the research really find?

We unpack the study’s most talked-about claims, including whether swapping just 10g of butter for plant-based oil could lower your risk of early death.

Plus, we dive into the bigger picture: Why fats are so polarising, the debate around seed oils, and how to navigate nutrition science in an era of misinformation.

Specifically, we cover:

Inside a Controversial New Study on Butter and Plant Oils (00:00)
How the 33-Year Nutrition Study Was Conducted (00:47)
What Observational Studies Can (and Can’t) Tell Us (03:01)
The Truth About Food Frequency Questionnaires (08:03)
Surprising Patterns in Butter and Oil Consumption (17:52)
Why One Common Oil Performed Better Than Expected (22:50)
Are We Misunderstanding Nutrition Guidelines? (26:13)
What Happens When Oils Are Heated Over and Over (28:28)
Do Oils Measure Up to Whole Food Fat Sources? (31:04)
The Great Oil Debate: A Preview and Reflection (34:07)
A Smarter Way to Navigate Conflicting Health Advice (43:40)

Want to support the show?

The best way to support the show is to use the products and services offered by our sponsors. To check them out and enjoy great savings, visit theproof.com/friends. You can also support the show by leaving a review on the Apple Podcast app and sharing your favourite episodes with friends and family.

This episode is brought to you by:

38TERA

Consider 38TERA's DMN prebiotic supplement a daily multivitamin for your gut. Formulated by yours truly and gastroenterologist Dr Will Bulsiewicz. Use code THEPROOF for a discount at checkout.

Momentous

My go-to supplement brand for protein and creatine is Momentous. Get 20% off your first purchase by using the code LIVINGPROOF at checkout at livemomentous.com

Shopify

Shopify, the world's leading e-commerce platform, helps you turn browsers into buyers with the internet’s best-converting check out–up to 36% better compared to other leading e-commerce platforms. To boost your conversion rate, and grow your business, sign up for a one-dollar-per-month trial period at shopify.com/proof.

Birch

Sleep deeply and wake up refreshed with a Birch Natural Mattress, combining premium natural materials with unbeatable comfort. Rest easy with a 100-night trial and 25-year warranty. Get 20% off sitewide and 2 free Eco-Rest Pillows at birchliving.com/simonhill.

Eimele

Eimele Essential 8 is a comprehensive multivitamin that is scientifically formulated to complement your plant-rich diet, increase and sustain your energy, and support the immune system, as well as heart and brain health. Follow [this link](https://eimele.com/essential-8/15660280.html.) for 20% off one-time purchases and subscriptions.

WHOOP

Whoop, the most advanced fitness and health wearable available. Your personalised fitness and health coach to recover faster, sleep better, and train smarter. Claim your first month free on join.whoop.com/simon.

Simon Hill, MSc, BSc (Hons)

• Creator of theproof.com

• Host of The Proof with Simon Hill

• Author of The Proof is in the Plants

Subscribe & Connect:

• YouTube

• Apple Podcasts

• Spotify

• Instagram: @simonhill

• Twitter: @theproof

• Facebook: The Proof with Simon Hill

Nourish your gut with my Plant-Based Ferments Guide and download my Two-Week Meal Plan.