74: Are We Eating Too Much Protein? with Dr. Paul Reynolds

The Protein Debate and Aging00:00:00

An introduction to the conflicting scientific perspectives on protein intake. The summary highlights that high protein signaling can promote growth but may also influence aging, noting that the 'optimal' amount is age-dependent.

Mechanisms of Glycation and AGEs00:01:32

Explanation of how glycation occurs when sugars damage proteins, forming Advanced Glycation End products (AGEs). The discussion emphasizes that preparation methods, specifically high-heat cooking like charring, contribute to exogenous AGE intake.

Protein and Mortality: The Age Interaction00:03:30

Analysis of the 2014 study by Levine and Longo, which shows that high protein intake is associated with higher mortality in those aged 50-65, but lower mortality in those over 65, emphasizing the importance of muscle maintenance in older populations.

Anabolic Resistance and the Leucine Threshold00:08:07

Discussion on anabolic resistance in older adults, where higher concentrations of leucine are required to trigger muscle protein synthesis. This suggests older adults need a higher protein density per meal to combat sarcopenia.

Dispelling Myths: Kidneys and Protein00:12:24

Review of scientific evidence indicating that higher protein intake does not damage healthy kidneys, clarifying that clinical protein restriction is only necessary for those with pre-existing, significant renal impairment.

The Protein Leverage Hypothesis00:16:22

Explaining that humans have a prioritized drive for protein; if the diet is protein-dilute (processed foods), individuals tend to overconsume total calories to meet their protein requirements.

Practical Recommendations00:23:52

Final advice: those under 65 may benefit from moderate intake and fasting; those over 65 should aim for at least 1.2g/kg of body weight. Regardless of age, the focus should shift to avoiding excessive dry-heat cooking methods to reduce AGE exposure.