Sauna Use as an Exercise Mimetic for Heart and Healthspan – FoundMyFitness with Dr. Rhonda Patrick

Check out the Found My Fitness Episode Page & Show Notes

Key Takeaways

  • USE THE SAUNA
  • Benefits of using the sauna include the reduced risk of: 
    • Sudden cardiac death
    • Cardiovascular-related mortality
    • Coronary heart disease-related death
    • Stroke
    • Hypertension
    • All-cause mortality
    • Alzheimer’s disease
  • Additional sauna benefits:
    • Reduced c-reactive protein levels (a marker of inflammation) 
    • Increased excretion of heavy metals
    • Enhanced mood
  • There’s tons of benefit overlap when it comes to using the sauna and exercising
    • Long-term, both improve blood pressure, heart rate and, heart rate variability 
  • Using the sauna is the best way to increase the body’s production of heat shock proteins 
    • Sitting in a 163 °F sauna for 30 minutes increases heat shock protein levels by ~50%
    • The most important thing heat shock proteins do: help maintain the proper 3-dimensional structure of cellular proteins
      • When a protein’s 3-dimensional structure gets altered, it tends to sit around much longer than it’s supposed to (instead of being degraded) – this causes it to start forming protein aggregates with other proteins. Protein aggregation has been shown to play a causal role in many neurodegenerative diseases.
    • Heat shock proteins also slow muscular atrophy (the wasting away of muscle)

Intro

  • This episode features a talk from Rhonda Patrick, PhD (@foundmyfitness) at the Heart Summit in Little Rock, AR

Setting the Stage

  • “I think, in the next 10 years, sauna bathing may very well become part of the standard of care for the prevention and treatment of heart disease, for a variety of heart conditions, and for overall longevity”
  • “You should be sitting in a hot box for about 20 minutes a day at least a couple of times a week”

Study Examination | Sauna Use Associated with Reduced Risk of Cardiac, All-cause Mortality

  • This study examined 2300 men who had at least one risk factor for cardiovascular disease
  • Findings:
    • Sudden Cardiac Death
      • Men who used the sauna 2-3x a week had 22% lower sudden cardiac death compared to men who used the sauna 1x a week
        • Men who used the sauna 4-7x a week had 63% lower sudden cardiac death compared to men who used the sauna 1x a week
      • By spending at least 11 minutes in the sauna, men experienced 11% lower cardiac death
        • Men who spent >19 minutes in the sauna saw a 50% reduction in cardiac death
    • Coronary Heart-related Death + Fatal Cardiovascular Mortality
      • Men who used the sauna 2-3x a week had 23% lower coronary heart disease-related death compared to men who used the sauna 1x a week
        • When using the sauna 4-7x a week, this number jumped to 43%
      • Men who used the sauna 2-3x a week had 27% lower cardiovascular-related mortality compared to men who used the sauna 1x a week
        • When using the sauna 4-7x a week, this number jumped to 50%
  • Note – The above data was adjusted for a variety of potential confounding factors (cholesterol levels, physical activity, etc.)

Study Examination | Frequent Sauna Bathing Reduces Risk of Stroke

  • Using the sauna 2-3x a week resulted in a 14% reduced risk of stroke (in both men and women) compared to men/women that only use the sauna 1x a week
    • Using the sauna 4-7x a week resulted in a 61% reduced risk of stroke 

Study Examination | Frequent Sauna Bathing Keeps Blood Pressure in Check

  • Using the sauna 4-7x a week resulted in a 50% reduction in hypertension risk
  • Just one 30-minute sauna session lowers blood pressure and increases arterial compliance (the ability of the blood vessels to expand/contract)

Notes on the Above Studies

  • All studies mentioned above utilized a Finish sauna (AKA a wet sauna) which typically hovers around 174 °F
    • With these, hot water is thrown on rocks (which are located on top of a heater) which then increases the humidity level inside the sauna to ~20%
  • Sauna duration in all studies was >20 minutes

Am Important Distinction

  • Dry saunas and wet saunas heat the ambient air
    • Infrared saunas use thermal radiation to heat the body directly

Study Examinations – Waon Therapy

Why does heat stress have all these beneficial effects on the cardiovascular system? | The Similarities of Sauna Use and Exercise

  • There’s a good amount of overlap between sauna use and exercise in terms of how they both raise core body temperature
  • Here’s what happens when using the sauna:
    • Skin temperature increases which then causes blood to be redirected to the skin to help facilitate sweating (this also happens during exercise)
    • Heart rate increases up to 150 BPM (this is equivalent to moderate physical activity)
    • Cardiac output increases (this too happens during exercise)
  • Sauna use mimics moderate aerobic activity
  • Sauna use increases heart rate variability (HRV)
  • Long-term sauna use has been shown to improve blood pressure, left ventricular function, vascular compliance, and endothelial function
    • All the above are improved by physical activity as well

Sauna Use Increases Longevity

  • Back to the first study mentioned, here are some more findings:
    • Sauna use reduces the risk of all-cause mortality
      • Men that use the sauna 2-3x a week have a 27% reduced risk of all-cause mortality and a 40% reduced risk when using the sauna 4-7x a week (compared to men who use the sauna just 1x a week)
    • Sauna use decreases Alzheimer’s disease (AD) risk
      • Men who use the sauna 2-3x a week have a 20% lowered risk of AD and a 60% reduced risk when using the sauna 4-7x a week (compared to men who use the sauna 1x a week)
  • There have also been a few studies on lower organisms like c. elegans and fruit flies showing a single heat exposure increases lifespan by up to 15%

Heat Shock Proteins (HSPs)

  • Heat shock proteins are increased under stressful conditions (although heat stress is the most robust method of increasing their production)
    • Exercise, fasting, and polyphenol consumption also increases HSP production
    • Sitting in a 163 °F sauna for 30 minutes increases HSP levels by 50% – these levels then stay elevated for ~48 hours
      • People who use the sauna more frequently tend to get an even better HSP response
  • What do heat shock proteins do?
    • They’re responsible for maintaining the proper 3-dimensional structure of cellular proteins – here’s why this matters:
      • Structure equates to function
      • When a protein’s 3-dimensional structure is altered, it tends to sit around much longer than it’s supposed to (instead of being degraded) – this allows it to start forming protein aggregates with other proteins
        • Protein aggregation has been shown to play a causal role in many neurodegenerative diseases
  • Heat shock proteins have also been shown to slow muscular atrophy
    • For this reason, it would be very beneficial to use the sauna if you were to break your leg and had to wear a cast
  • Certain humans have a SNP (pronounced “snip”) in the HSP 70 gene which allows their HSPs to do better a job of maintaining the 3D structure of cellular proteins

Sauna Use Lowers Inflammation

Additional Sauna Benefits

  • Using the sauna enhances mood by increasing endorphins in the brain 
  • Excretion of heavy metals (cadmium and mercury, both of which are better excreted in sweat compare to urine)

Audience Questions

Is there an additive effect in regards to sauna-use, exercise, and all forms of fasting?

  • Definitely in terms of physical activity and sauna use
    • It’s been shown that people who are physically active and use the sauna experience improvements in muscle mitochondrial function

Are there limits on sauna duration and frequency?

  • 20 minutes seems to be key if the sauna is at a temperature of ~174 °F – try to hit this
    • Rhonda tries to stay in for ~30 minutes (and her sauna is ~175 °F)
  • Over time, you become acclimated

Finish sauna or infrared sauna?

  • Finnish
    • With infrared saunas, you have to stay in for much longer

Why are there no Blue Zones in Finland?

  • Perhaps it’s because of their diet or the fact that it’s dark for a large percentage of the year

Is there an age limit for sauna use?

  • In Finland, people of all ages use the sauna
    • Younger kids tend to use it for shorter durations

Other Tools for Increasing Healthspan

  • Time-restricted eating will give you the biggest bang for your buck (eating all your food within a certain time window, typically between 6-11 hours)
    • It’s much easier to get patients to comply with this compared to having them change their diet
    • “Throughout human history, there were periods of time when we didn’t have access to food. We have all these amazing genetic pathways that are meant to be switched on and they won’t be unless you stop eating for a certain period of time.”
      • These genetic pathways help:
        • Deal with the stresses of aging
        • Clear our accumulated cell debris
    • Time-restricting your eating also forces you to eat your food when you’re most insulin sensitive (assuming your eating window doesn’t run later into the night)
      • Humans are much more insulin sensitive in the morning compared to the evening
        • Why is this the case? – The genes that regulate the body’s processes are on a circadian rhythm (the thing that starts this clock is the intake of food)
  • Prolonged fasting
    • For more on the benefits, check out the Podcast Notes from Rhonda’s interview with Dr. Valter Longo. Highlights include:
      • Fasting before chemotherapy/radiation sensitizes cancer cells to death and protects normal cells from the toxicity of the treatment
      • During a prolonged fast, the body undergoes autophagy (the self-eating process by which damaged cells are killed off)
        • During the refeeding phase, stem cells proliferate and replace the cells which were lost
  • Eat more broccoli sprouts (which contain sulforaphane)

Additional Sauna Notes

  • It’s important to rehydrate after the sauna
    • During a typical sauna session, you’ll lose about ~0.5 kg of sweat
  • Rhonda uses the sauna 4x a week
  • NEVER drink alcohol before or while using the sauna
  • Hot baths have similar effects to the sauna in regards to enhancing mood
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