Dr. Jeremy London is a heart surgeon who uses the sauna. Let that sink in for a moment. The person whose entire career is spent repairing damaged hearts has decided that heat exposure belongs in his non-negotiables. Not as an experiment. As a five-year practice. That kind of clinical conviction deserves attention.
The numbers he cites are real. A 50% reduction in cardiovascular event risk. A 60 to 65% decrease in Alzheimer's and dementia risk. These aren't fringe findings — they come from large Finnish population studies tracking thousands of people over years. The dose-response relationship is clear: more frequent use produces greater protection.
What strikes me about this conversation is how it complements the mechanistic work we see elsewhere. Rhonda Patrick has covered the same Finnish data extensively — the JAMA Internal Medicine studies showing that four to seven sessions per week cuts cardiovascular mortality dramatically. Andrew Huberman's deep dive explains the physiology: your heart rate climbs to 100-150 beats per minute in a hot sauna, plasma volume expands, vasculature dilates. You're training your circulatory system to be more adaptive, more flexible, with every session.
Dr. London lands on the same protocols the research supports: 12 to 19 minutes, 185 to 210 degrees Fahrenheit. This isn't arbitrary. It's the range where heat shock proteins are activated, where cardiovascular adaptation occurs, without pushing into territory that becomes more stressor than benefit.
There's genuine consensus on the cardiovascular and cognitive protection data. The mechanisms are plausible and the epidemiological signal is strong. Where things get more nuanced is the Alzheimer's connection — most of that research is observational. We know sauna users have lower rates of cognitive decline. We know heat shock proteins clear misfolded proteins linked to neurodegeneration. The causal chain is biologically coherent. But the randomized controlled trials to confirm it are still being done.
That said, Dr. London's framing is honest: when the burden of evidence is this strong and the downside risk is minimal, waiting for perfect certainty before acting is its own kind of risk.
Start with what's accessible. Three sessions per week, 15 minutes, whatever temperature you can sustain. Build consistency before you optimize. Hydrate before you go in. Give yourself 10 minutes to cool down afterward — don't rush back into activity. If you have access to contrast therapy, the sequence of heat followed by cold amplifies both the cardiovascular and recovery effects. But the sauna alone is already doing serious work.
Seven people in a sauna on a family farm in the South. That detail from Dr. London's transcript is easy to gloss over, but it points to something the biochemistry doesn't capture. The oldest sauna cultures — Finnish, Russian, Indigenous — have always used heat as a communal ritual. Not just a health protocol. A shared experience that builds connection, trust, and belonging.
There's emerging research suggesting that social connection is itself a longevity variable — as significant as exercise or diet for healthspan. When you put those two things together in the same ritual, you're not just stacking physiological benefits. You're building something that sustains a practice over years. Dr. London has been doing this for five years. The seven people in that cedar cabin together are one reason why.