This study analyzed the same cohort of 2,315 healthy men over a 20-year follow-up period to determine the relationship between sauna habits and the development of memory diseases.
The Bottom Line
Participants who used the sauna 4-7 times a week had a 66% lower risk of developing dementia and a 65% lower risk of Alzheimer's disease compared to those using it once a week. This suggests sauna bathing may be a powerful neuroprotective habit.
The Science
Building on the cardiovascular findings, Dr. Laukkanen's team examined the same 2,315-man cohort for cognitive outcomes. Over the 20-year follow-up, 204 cases of dementia were diagnosed, including 123 cases of Alzheimer's disease. The results were striking: men who used the sauna 4-7 times weekly had a hazard ratio of 0.34 for dementia (66% reduction) and 0.35 for Alzheimer's (65% reduction) compared to once-weekly users.
The neuroprotective mechanisms likely involve multiple pathways. Heat stress activates brain-derived neurotrophic factor (BDNF), a protein crucial for neuron growth and cognitive function. Improved cardiovascular health from regular sauna use also benefits the brain—what's good for the heart is good for the brain. Additionally, heat exposure reduces inflammation and oxidative stress, both implicated in neurodegeneration.
The relaxation response triggered by sauna use may also play a role by reducing cortisol and chronic stress, known risk factors for cognitive decline. Regular sauna bathing essentially creates a "cardiovascular workout" for the brain's blood supply while simultaneously activating protective cellular mechanisms.
What This Means for Your Sauna Choice
For brain health benefits, consistency matters more than intensity. Both traditional and infrared saunas can provide the heat stress needed to activate BDNF and improve cerebral blood flow. If you're new to sauna use, an infrared model operating at 130-150°F may be more comfortable for building a sustainable 4+ times weekly habit. The key is regular, repeated heat exposure over months and years—choose a sauna you'll actually use consistently.
Source: Age and Ageing, 2017