[@PeterAttiaMD] Cooking with Lard vs Seed Oils | Layne Norton, Ph.D.

Link: https://youtu.be/7_cbaDXAWYM

Duration: 12 min

Short Summary

This episode examines the science behind seed oils, oxidation during frying, and the debate over saturated fats versus unsaturated oils for cardiovascular health. Host Lane and guest Peter discuss that no direct human RCT compares frying with lard versus seed oils, while presenting converging evidence that apoB-containing lipoproteins are atherogenic based on Mendelian randomization studies and statin trials. Practical takeaways include limiting saturated fat, eating enough fiber, and prioritizing larger health factors over seed oil concerns.

Key Quotes

1. "My PhD adviser used to say, "If I wanted to design a study to show no effect or the study to show an effect, easiest thing in the world."" (00:12:31)
2. "people think food companies care about which foods you buy. They just want you to buy." (00:07:15)
3. "you can never prove anything, right? Like we can only disprove things, but we can have relative degrees of confidence in various data, right?" (00:13:52)
4. "It's like we're we're stepping over $100 bills picking up pennies, you know?" (00:19:02)
5. "the average calorie consumption in the United States is 3,500 calories per day, and the average physical activity is less than 20 minutes per day." (00:18:46)

Detailed Summary

Seed Oil Processing and Oxidation Science

The episode discusses seed oil processing, explaining that it occurs under vacuum with virtually no oxygen, resulting in minimal oxidation even when heated, unlike restaurant frying conditions. Research presented shows that oil thickness significantly impacts oxidation rates—moving from 1 cm to 5 cm depth creates a huge difference, with thin-layer frying producing negative products within 20-30 minutes. Continuous heating of oil in restaurant frying vats leads to significant oxidized trans fats accumulation over time. Saturated fats are noted as less prone to oxidation when heated compared to polyunsaturated fats.

The Seed Oil vs. Saturated Fat Debate

The speakers examine the controversy around seed oils versus saturated fats like lard and tallow. Lane points out that food companies market whatever sells, and switching to tallow/lard can be misinterpreted by consumers as healthier, potentially increasing consumption. Peter raises the question of whether, if LDL can be controlled pharmacologically with statins, the focus should shift to other potential harms like oxidation products from frying oils. A key admission is that no human RCT exists comparing health outcomes of frying with lard versus seed oils, as competing mechanisms make it difficult to determine which is worse.

apoB and Cardiovascular Health Evidence

Lane expresses high confidence that apoB-containing lipoproteins are atherogenic based on converging evidence, especially Mendelian randomization studies and statin trials, though would require substantial data over time to change this view. The discussion addresses whether aldehydes and oxidation products from frying oils become more important health concerns after addressing LDL with statins. Both speakers emphasize that there are elements of truth to criticisms of seed oils, but the balance across hard outcomes must be considered.

Scientific Rigor and Study Interpretation

The episode emphasizes relying on converging lines of evidence and the most high-quality, rigorously controlled studies. Lane notes that 99 out of 100 times reading the actual scientific study explains seemingly weird outcomes, often due to control group design or group level differences. A PhD adviser is quoted stating that designing a study to show no effect or a specific effect is "the easiest thing in the world." The scientific principle is highlighted: you can never prove anything in science, only disprove things; we can only have relative degrees of confidence in data. Every study has limitations, but pointing out limitations doesn't mean a study is bad—interpretation should be careful about how broadly results apply.

Practical Recommendations and Summary

For those avoiding seed oils, the recommendation is to displace saturated fat with leaner protein sources and lower saturated fat alternatives like olive oil or avocado oil. The final recommendation is to limit saturated fat, eat enough fiber, and recognize that outside of those priorities, seed oils are not a major health lever compared to bigger factors. Contextual data presented includes that average calorie consumption in the United States is 3,500 per day, with average physical activity below 20 minutes per day.

Transcript: Download plain text