Do high saturated fat diets lead to heart disease? | Peter Attia and Don Layman

Summary

The transcript covers a discussion between two individuals reflecting on the research legacy of Ancel Keys at the University of Minnesota. They review Keys' famous seven countries study linking dietary saturated fat to heart disease, as well as his human starvation experiments. The discussion centers around analyzing and interpreting Keys' 1970s Minnesota Coronary Experiment which compared a high saturated fat diet to a high polyunsaturated fat diet in institutionalized patients. Though the polyunsaturated fat group had lower cholesterol, there was no difference in cardiac events after 5 years. They debate the meaning of these results in light of subsequent research questioning saturated fat's link to heart disease.

Takeaways

• 😊 Don wasn't an expert on lipids but remembered the Minnesota Coronary Experiment study
• 🧐 The evidence on saturated fat and heart disease has been mixed overall
• 🤔 The cholesterol and saturated fat hypotheses have weakened over time
• 😮 A seminar speaker warned about trans fat dangers years before policies changed
• 🤨 The Minnesota study found no difference in events despite cholesterol changes
• 😕 Ansel Keys had major influence on diet-heart disease ideas at Minnesota then
• �ToString The Minnesota study may have been too short to show diet effects
• 🤔 Don believes calories matter most for obesity, macros for lean healthy people
• 😒 Selective publishing and excuses maintained diet-heart hypotheses over time
• 🤷‍♂️ Saturated fats don't seem problematic for weight-stable people

Q & A

What were the two things Ancel Keys was famous for when the narrator was at the University of Minnesota?

Keys was famous for the seven country study, which promoted the idea that saturated fat in the diet causes heart disease, and for starvation experiments done in the 1940s or 1950s to study the effects of starvation on the human body.

What did the narrator start to realize about the diet-heart hypothesis as he conducted research early in his career?

The narrator started to realize he didn't really believe the hypothesis that saturated fat and cholesterol cause heart disease, based on experiments he did involving fasting and malnutrition.

What happened after Fred Kummerow suggested at a Minnesota seminar that cooking oils and trans fats were dangerous?

Kummerow was ridiculed at the seminar, but 20 years later trans fats were banned from foods as the most dangerous type of fat.

What were the two diets compared in the Minnesota Coronary Experiment conducted by Ancel Keys?

One diet was high in saturated fat and one was high in polyunsaturated fat. The goal was to see if the diet lower in saturated fat would reduce risk of heart attacks and strokes.

What were the main results of the Minnesota Coronary Experiment?

After 5 years there was no difference in cardiovascular events between the high saturated fat and high polyunsaturated fat groups, even though cholesterol levels were lower in the polyunsaturated group.

Why does the narrator think the Minnesota Coronary Experiment may have been underpowered?

The narrator initially thought 5 years may not have been long enough to appreciate a difference in events between the diet groups if one existed.

What did further analysis of the Minnesota Coronary Experiment data show?

Further analysis showed some subgroups actually had more coronary events on the high polyunsaturated fat diet.

What is Dr. Layman's view on the diet-heart hypothesis related to saturated fat?

Dr. Layman believes the evidence on saturated fat and heart disease is mixed and the hypothesis has weakened over time as better studies are done.

What does Dr. Layman believe is most important if your goal is to be lean and healthy?

If the goal is to be lean and healthy, Dr. Layman believes total calories are what matters most, not the breakdown of macros.

When might saturated fat quality start to matter more according to Dr. Layman?

If someone is committed to being obese, Dr. Layman says saturated fat quality would become more important to consider.