The Wellness Brew - Issue 12

Sauna use has skyrocketed in recent years, going from a Finnish tradition to a wellness industry staple. This week, we dive into into what the evidence on sauna use actually shows, what the protocols look like in practice, and what to know before buying one. But first, we filtered the noise — here's what's worth knowing this week.

Ten bodyweight squats every 45 minutes beat a single 30-minute walk for blood sugar

If you are one of the many people stuck at a desk all day, finding time for frequent walking breaks can be a real challenge. A quicker and potentially more effective alternative is ten bodyweight squats every 45 minutes. A 2024 study by researchers at Zhejiang University compared continuous sitting, a single 30-minute walk, three-minute walking breaks every 45 minutes, and ten bodyweight squats every 45 minutes. The squats and the frequent walking breaks both reduced post-meal glucose spikes by 21 percent compared to continuous sitting, and both outperformed the single 30-minute walk. Ten squats take roughly 20 seconds and require no equipment. The reason they work is that skeletal muscle in the lower body is responsible for the majority of glucose disposal, and frequent activation of the quadriceps and glutes pulls glucose out of the bloodstream. The sample size here is small (18 healthy young men) and follow-up studies in older adults and women are ongoing. But the mechanism is well-established and the protocol takes minutes per day. — Gao et al., Scandinavian Journal of Medicine and Science in Sports, 2024. 

A single infusion of an experimental gene-editing therapy lowered LDL cholesterol by up to 62%

Last week, Eli Lilly and Verve Therapeutics announced Phase 1b results for VERVE-102, an experimental gene-editing therapy that permanently shuts off the PCSK9 gene in the liver to lower LDL cholesterol. Published in The New England Journal of Medicine, the study followed 35 adults with familial hypercholesterolemia or premature coronary artery disease. A single intravenous infusion lowered PCSK9 protein levels by up to 88 percent and LDL cholesterol by up to 62 percent, with effects sustained over 18 months of follow-up. The therapy mimics the protective effect of naturally occurring PCSK9 loss-of-function variants, which are associated with markedly lower lifetime cardiovascular risk. If this works at scale, it represents something genuinely new: a single-dose, potentially lifelong treatment that could replace daily statin therapy for high-risk patients. Several hurdles remain before that future arrives. Phase 2 trials begin this year. The treatment has not been studied in lower-risk patients. Pricing, long-term safety, and regulatory approval are all unresolved. But the early results are striking and the data are strong enough that this is worth watching closely. — Lilly et al., New England Journal of Medicine, 2026.

Dr. Rhonda Patrick on curcumin, TNF-alpha, and the case for a more bioavailable form

Dr. Rhonda Patrick recently discussed how she has started supplementing daily with phytosomal curcumin, the active compound in turmeric. Curcumin is one of the more potent natural compounds for lowering TNF-alpha, a major inflammatory cytokine implicated in everything from rheumatoid arthritis to cardiovascular disease to Alzheimer's. In her words, curcumin is "the most naturally occurring dietary compound" she has seen evidence for in lowering TNF-alpha. The form matters. Standard curcumin has notoriously poor bioavailability and is rapidly cleared by the liver. Phytosomal curcumin (sold as Meriva or CurcumaSorb) wraps the compound in phospholipids, increasing absorption by roughly 18-fold compared to standard formulations. Patrick takes 1 gram per day. Two caveats worth knowing. Curcumin trials have noted abnormal liver enzyme elevations in a small percentage of users at longer durations, so periodic bloodwork is reasonable if used daily long-term. And turmeric itself has documented contamination problems with lead, so brand and sourcing matter as they did in our recent issue on supplement quality. — Patrick, FoundMyFitness, 2025-2026.

Saunas are Having a Moment

Sauna use has gone from a Finnish tradition to a fixture of the American wellness conversation. Home sauna sales have more than doubled in the past five years, every other longevity podcast now features a sauna-and-cold-plunge protocol, and gyms across the country have added saunas as a competitive amenity rather than an afterthought.

What separates sauna use from most trends in the wellness space is that the underlying evidence base is unusually strong. The centerpiece is the Kuopio Ischemic Heart Disease Risk Factor Study, known as KIHD, a Finnish cohort of 2,315 middle-aged men followed for more than 20 years.[1] That single study, and the analyses that have come from it over the past decade, sits behind nearly every confident claim circulating today about sauna and longevity. The rest of the literature is less rigorous, but the foundation is real.

Most of what you have heard about sauna use is grounded in actual data. Below, we’ll review what the evidence really says and we’ll dig into risks that are usually left out, the protocols with evidence behind them, and the key factors you want to look for when buying a sauna.

What the Evidence Shows

Cardiovascular mortality. The KIHD analysis published in JAMA Internal Medicine in 2015 followed 2,315 Finnish men for a median of 20.7 years. Men who used the sauna 4 to 7 times per week had a 50 percent lower risk of fatal cardiovascular disease and a 40 percent lower risk of all-cause mortality compared to men who used the sauna once per week. Sessions of 19 minutes or longer were more protective than 11 to 18 minute sessions.[1] A 2018 follow-up study extended these findings to women, showing similar dose-response relationships.[2] The mechanism appears to be improved endothelial function, reduced arterial stiffness, and beneficial changes in blood pressure regulation that come from repeated heat exposure.

Blood pressure and stroke. Separate KIHD analyses found that 4 to 7 sauna sessions per week were associated with a 46 percent lower risk of developing hypertension and a 61 percent lower risk of stroke compared to once-weekly users.[3][4] The blood pressure findings are particularly well-explained mechanistically. Heat exposure causes acute vasodilation, and repeated exposure appears to improve the endothelium's ability to dilate on demand, lowering resting blood pressure over time.

Dementia and Alzheimer's. Another KIHD analysis also found that 4 to 7 sauna sessions per week were associated with a 66 percent lower risk of developing dementia and a 65 percent lower risk of Alzheimer's disease compared to once-per-week users.[5] These are observational findings and cannot prove causation. The presumption is that sauna use results in improved cerebrovascular function, reduced systemic inflammation, and the activation of heat shock proteins that protect against protein misfolding, a hallmark of neurodegenerative disease.

One point worth mentioning — all three of these findings come from the same Finnish cohort, which means the population studied is narrow (middle-aged Finnish adults with cultural sauna habits going back generations). The results may not translate identically to American adults who started using a sauna last year. The direction and magnitude of the findings, however, are consistent enough across analyses that the broader pattern is supported.

The Risks No One Talks About

The wellness conversation around sauna tends to skip over the downside entirely. There is one risk that deserves the most attention, and a smaller bucket of obvious risks worth being aware of.

Fertility — Men in their reproductive years need to know about this risk, and it is almost never discussed in mainstream sauna content. The testicles sit outside the body because they need to be 2 to 4°C cooler than core body temperature for healthy sperm production. Sauna directly disrupts that. A 2013 Italian study published in Human Reproduction (Garolla et al.) found that men who used a Finnish sauna at 80 to 90°C for 15 minutes twice per week, over a three-month period, experienced significant drops in sperm concentration, motility, and morphology.[6] Sperm DNA fragmentation also increased. The good news is that the effects were fully reversible within six months of stopping sauna use, consistent with the roughly 70-day cycle of sperm production.

The practical implication is narrow but important. For couples actively trying to conceive, regular sauna use is something to pause for the months preceding and during the conception window. For everyone else, the effect is temporary and not a reason to avoid the sauna entirely. Men who want to use the sauna routinely without the fertility tradeoff can consider placing a cooling pack or ice pack over the genital area during sessions. The cooling approach has mechanistic logic behind it (it directly counteracts the rise in temperature), though it has not been studied as a formal intervention.

The obvious risks worth knowing. Sauna use can cause dehydration, hypotension, and lightheadedness, particularly in people who are new to it or who push session length too far. Loss of 0.5 to 1.5 liters of sweat per session is normal, and that fluid needs to be replaced. The more consequential combination is alcohol plus sauna, which is a documented risk factor for serious heat-related events including heat stroke and sudden cardiac death.[7] These are real risks, but they are also the obvious ones. Drink water while you’re in the sauna and after. Don’t drink alcohol before or during use and make sure to step out if you begin to feel lightheaded.

What Makes a Quality Sauna

This is the question almost nobody asks and it matters more than most of the protocols being discussed. There are three critical characteristics worth getting right.

Construction materials. The interior of a sauna should be solid wood. Cedar, eucalyptus, and hemlock are the most common high-quality options. Be sure to avoid plywood, particleboard, MDF, and any engineered wood product held together with adhesives. The reason is that most engineered wood products use urea-formaldehyde or phenol-formaldehyde adhesives, which off-gas formaldehyde at room temperature and off-gas dramatically faster when heated. A traditional sauna at 176°F is one of the worst possible environments for formaldehyde-based adhesives. You are sitting in a small enclosed superheated space, breathing deeply, with your pores open. A 2013 peer-reviewed study published in BioResources documents that emissions from heated wood products increase substantially as temperature rises.[8] Formaldehyde is classified as a known human carcinogen by the International Agency for Research on Cancer. The interior should be solid wood. Glues, stains, and synthetic finishes should be avoided entirely, or used only on external surfaces.

Ventilation. A sauna needs both intake and exhaust ventilation to prevent CO₂ buildup and to circulate the air. Poor ventilation in a sealed sauna leads to stale air, rising CO₂ levels, and a less effective heat session. Better-designed saunas have intake vents near the floor and exhaust vents near the ceiling on the opposite wall, allowing convection to do the work.

Heat source position. The traditional design places the heat source below the seating area, so heat rises through the body. This produces a more even thermal stimulus than designs that heat from above or behind. It is also the configuration used in nearly all the research cited above. Look for saunas where the bench is elevated rather than those with a bench at floor-level.

Optimal Protocols by Goal

The research supports different protocols for different outcomes.

For cardiovascular and longevity benefit (the strongest evidence base):

For acute growth hormone response (limited evidence base, periodic use only):

One note on temperature. No evidence supports that temperatures above these ranges produce additional benefit, and they likely increase acute risk.

Infrared Saunas

We’d be remiss if we didn’t touch on infrared saunas. Infrared saunas have become popular largely on the marketing claim that they deliver equivalent benefits to traditional saunas at lower, more tolerable temperatures (typically 122 to 149°F versus 174°F+). The idea is that the infrared light stimulates deeper into your body, thus resulting in equivalent core body temperature increases with lower heat. However, the evidence does not support this claim.

A 2025 study published in the Journal of Applied Physiology (Williams et al.) directly measured intramuscular temperature during a 45-minute commercial far-infrared sauna session. The researchers found no change in core body temperature at all.[10] The authors concluded that "commercially available far infrared saunas provide only superficial heating of peripheral tissues." This directly contradicts the standard marketing claim that infrared "penetrates deeply" into muscles and joints.

One additional point worth addressing. Many infrared sauna brands market their products as offering red light therapy benefits, often bundling small red LED panels into the cabin. This is not the same as a dedicated red light therapy device. Red light therapy works through red and near-infrared wavelengths in the 630 to 850 nm range, which are absorbed by mitochondrial cytochrome c oxidase, stimulating ATP production at the cellular level. Clinical protocols target an irradiance of 30 to 100 mW/cm² delivered directly to the treatment area. Achieving that dose requires sitting within 6 to 12 inches of a high-output panel, often closer for deeper tissue targets.

The small red LEDs built into most infrared saunas are not clinical-grade, not positioned close enough to the body to deliver a meaningful irradiance, and often not emitting the right wavelengths in the first place. If you want red light therapy, buy a dedicated red light panel. If you want a sauna, buy a traditional sauna.

The Bottom Line

Sauna use is one of the rare wellness practices where the evidence is strong, the protocols are clear, and the risks are manageable as long as you know what they are. The actionable takeaways below translate the research into the practical decisions that actually matter: what to buy, how to use it, and when to skip.

Three things you can do this week:

1. Choose a sauna built with the right materials. The interior should be solid wood — cedar, eucalyptus, or hemlock. No plywood, particleboard, or MDF anywhere inside the cabin. No formaldehyde-based adhesives. Tongue-and-groove joinery is the traditional method and avoids the need for glue. Ventilation should pull air in near the floor and exhaust it near the ceiling. The heat source should sit below the bench, with the bench itself elevated rather than at floor level. The construction matters more than nearly any other variable.  

2. Build up to the cardiovascular protocol. Start with 2 to 3 sessions per week at 15 to 20 minutes and 175°F. Build toward 4 to 7 sessions per week over weeks to months. This is the protocol most directly supported by the KIHD evidence, and the one associated with the largest reductions in cardiovascular mortality, hypertension, stroke, and dementia. 

3. Pause the sauna if you are trying to conceive. Regular sauna use measurably impairs sperm production, with effects fully reversible within six months of stopping. For couples actively trying to conceive, pause regular sauna use for the months leading up to and during the conception window. Men who want to use the sauna routinely outside that window may also want to consider placing a cooling pack or ice pack over the genital area during sessions.

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The Wellness Brew

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Disclaimer: The Wellness Brew is for informational purposes only and does not constitute medical advice. The content published here is not intended to diagnose, treat, cure, or prevent any disease or health condition. Always consult a qualified healthcare professional before making any changes to your diet, supplement routine, or lifestyle.