STEM-Talk
Episode 199: Ken and Dawn respond to listener questions on aging, meat consumption and dementia, genetic testing, AI, exercise, a lunar mission and much more
// Sep 15, 2026
Today we have the second of a two-part AMA. In part one, episode 198, we covered a multitude of listener questions about AI, which lately seems to dominate the news cycle. Other than one AI question that managed to sneak in, today’s AMA features a wide range of questions on a number of topics other than artificial intelligence.
Today, Ken and Dawn respond to listener questions that range from:
— Whether there’s a critical difference between whey protein powders and ready-to-drink protein shakes?
— Is there a sweat spot for how much time a person should spend on resistance training during a week?
— Ken’s thoughts on a paper that looked at whether higher meat consumption could be associated with a lower risk of dementia among people carrying the APOE ε4 gene variant.
— What kind of Pandora’s box will we open if parents start doing genetic tests on their infants to see if their children have, say, the APOE ε4 gene variant?
— Will NASA will be able to meet its target date of sending astronauts back to the Moon by 2028?
— And a lot more.
Show notes;
[00:03:05] A listener asks Ken about the 2019 Trim study by Gregory Fahy and colleagues in Aging Cell, which reported reversal of epigenetic aging and signs of thymic regeneration in nine healthy men treated with the growth hormone, DHEA, and metformin. [00:06:56] Ken responds to a question about the market being flooded with protein supplements. The listener asks if whether there’s a critical difference between whey protein and ready-to-drink protein shakes, and if there are any specific products he recommends. [00:10:50] A listener asks Ken about a recent article in Nature Reviews Neuroscience titled: [00:15:26] A listener asks Ken about a Chinese company called Moonshot AI and its open-weight model, Kimi K3. The listener references Gary Marcus who anticipates that the power of this model paired with the open-weight design will have immense implications. The listener asks for Ken’s take. [00:25:56] A listener mentions that they’ve heard that Ken likes to tell graduate students a fable about a rabbit pursuing their Ph.D. A listener asks Ken if he would share the fable. [00:30:15] A listener asks Ken about a study published in Jama Network Open by Norgren and company which suggests that higher meat consumption may be associated with lower Alzheimer’s risk for people carrying the APOE 4 gene variant, the strongest common genetic risk factor for late onset Alzheimer’s. [00:38:24] A listener mentions in their question for Ken that the Department of Health and Human Services recommends at least 150 minutes of moderate exercise per week, but this recommendation does not break down how much of that time should be spent on aerobic versus strength training. The listener goes on to mention a study in the that looked at identifying this sweet spot for resistance exercise, finding that between 90-119 minutes per week of weightlifting was associated with a 13 perent lower risk of premature death and a 27 percent reduction in neurological disease mortality, particularly Alzheimer’s. The listener also mentions that they are aware of IHMC’s ongoing clinical trial looking at the ability of exercise to mitigate the hallmarks of aging in people over 60 years old. The listener asks if this study is similarly trying to identify a sweet spot for resistance exercise, and if Ken has any recommendations on this topic. [00:46:32] Another listener mentions that they really enjoyed our interview with Doug Cooke on the Artimis II mission (episode 195), as well as our interview with Mike Griffin and Lisa Porter about NASA’s plan to return to the moon (episode 189). The listener goes on to mention that since then a Blue Origin rocket, one of the companies responsible for building a lunar lander, exploded on the launch pad in Florida. The listener asks if Ken is he’ still skeptical about the Artemis III mission architecture and timeframe in light of the recent news. [00:54:37] A listener asks Ken for his thoughts on the growing research efforts to investigate the feasibility of doing genetic testing on infants to identify their predisposition to specific diseases such as Alzheimer’s. [01:01:57] A listener asks for Kens thoughts on a study of creatine’s effects on physically active vegans. The study reported that 4 weeks of creatine supplementation improved lower-body power, especially jump height and flight time. But they did not find improvements in strength tests. [01:08:10] A listener asks for Ken’s thoughts on a recent White House report “Science: A New Golden Age”, which argues that the American scientific enterprise needs to be reformed and that agencies like NSF have become overly bureaucratic, slow, and risk averse.Links: