202 - Peter on nutrition, disease prevention, and more — looking back on the last 100 episodes

KEYPOINTS

• 01

  Strong convictions, loosely held.

  Looking back on episodes 100–200, Attia describes holding firm positions while staying ready to change them when evidence shifts. The episode is a tour of where his thinking evolved: cancer, apoB, Alzheimer's genetics, fasting, protein, exercise, NAD, psychedelics and sleep, ending with a long primer on Formula 1.

• 02

  His book has been a six-year project.

  Begun in 2016, the manuscript had ballooned; his editor hoped for about 80,000 words, and Attia and co-writer Bill Gifford aimed to converge on around 120,000, still thick but manageable.

• 03

  Immunotherapy works for a minority, so far.

  Checkpoint inhibitors and IL-2 produce durable responses in perhaps 10–20% of people with metastatic melanoma or renal cell cancer. Of cancer deaths, leukemias and lymphomas account for about 20% and solid organ cancers about 80%, so the big task is getting immune-based therapy to work across the solid tumors that make up the rest.

• 04

  GI cancers make a strong case for aggressive screening.

  Of roughly 600,000 US cancer deaths, about 170,000 are in the digestive system, from mouth to anus. Colonoscopy timing and frequency matter: guidelines say 45–50, Attia had his first at 40–41 and was scheduled for another at 49. Pancreatic cancer lacks good screening, so he uses tools like diffusion-weighted MRI and liquid biopsies, which are imperfect.

• 05

  ApoB should be lowered early and far.

  Attia argues infantile apoB levels of 30–40 mg/dL are not harmful, and that lowering apoB to 20–30 in everyone from their 20s might nearly eliminate ASCVD. Practically, anyone in their late 30s or early 40s above the 20th percentile should be treated. He uses 60 mg/dL (about the 5th percentile) as a ceiling.

• 06

  APOE4 risk is real but modifiable.

  Attia's rough figures: E2/E4 is a wash or slight increase; E3/E4 confers about a 2–3-fold risk of Alzheimer's; E4/E4 about 8–12-fold (maybe 8–10). At the individual level many E4 carriers never develop disease, and other genes modify that risk.

• 07

  Time-restricted eating mostly works by eating less.

  Attia now thinks the benefit of TRE comes largely from calorie reduction, not timing: 3,000 calories over 12 hours vs. 6 hours likely differ little. It can be problematic when people lose lean mass along with fat, so the scale improves while body composition worsens.

• 08

  Most people under-eat protein.

  Attia calls the RDA of about 0.8 g/kg 'out to lunch': for an 80-kg (about 175-lb) person that's around 65 g a day. He believes the RDA reflects the minimum to avoid deficiency, not what's optimal for building and keeping muscle, especially with age.

• 09

  Exercise is the most potent longevity tool.

  Moving from the bottom 25th percentile of cardiorespiratory fitness to the next quartile (low, below average, above average, high, elite) brings large mortality reductions, and the gains continue up the scale. Strength matters even more than muscle mass, though mass is a good proxy.

• 10

  He's uninspired by NAD precursors and wary of psychedelic hype.

  Attia sees little evidence that NR or NMN extend healthspan. On psychedelics, he thinks they're a powerful therapeutic tool in the right setting but worries about treating them as a cure-all, given how often he hears people raving about a shaman in Peru.

• 11

  Trazodone has become his favored sleep aid.

  An old antidepressant (a serotonin antagonist and reuptake inhibitor), trazodone caused too much drowsiness at 250–300 mg. At 25–100 mg nightly off-label, Attia says it helps more than 80% of the people who try it and, crucially, preserves sleep architecture, unlike drugs such as Ambien that just render you unconscious. He's also less worried about blue light than the stimulation of what you do on screens.