Hormesis Part 3 by Katherine Snook
Saunas, steam rooms, and other modes of heat and hydrotherapy have been used for centuries for relaxation, stress and muscle soreness relief as well as to “rid the body of toxins” and boost immunity. To continue on with my series about hormesis, I will speak on the benefits of heat exposure and how we can benefit from other activities that make us sweaty, like exercise.
There are many benefits from increasing your core temperature and slightly stressing the body, such as preventing muscle atrophy (losin’ it ‘cause you aren't usin’ it), improvements in focus, learning and memory, increased endurance, growth of new brain cells, improvements in depression and anxiety, easier acquisition of muscle mass, general increased capacity for stress tolerance, increased insulin sensitivity (1), decreased inflammation, increased cardiovascular and circulatory function (2), protection against neurodegenerative diseases, and prolonged ageing (3). Those are some amazing benefits!
To explain how heat therapy can elicit so many benefits, I’m going to introduce one mechanism behind it- Heat Shock Proteins, or HSPs. Proteins have many jobs within the body, they are used for communication between cells, delivery of certain molecules such as oxygen, catalysts in chemical reactions, and they are a huge component of our immune system. Basically, they perform all biological functions of the cell. When our cells create proteins (from the instructions of our DNA) sometimes things can go wrong and they are misfolded. Other times, our proteins get denatured from oxidative stress, physical trauma, mitochondrial damage, oxygen deprivation, and other stresses to the body (4). HSPs can help to clean up misfolded proteins and stabilize deformed proteins, preventing them from clumping. They can also help guard other proteins during times of stress to stop them from becoming abnormal (5). Our bodies ability to clean up damaged proteins declines with age, and the loss of protein homeostasis is a hallmark of the aging process across species (3). Preventing proteins from clumping or remaining misfolded or deformed is particularly important for the prevention of diseases like Alzheimer's, which is caused by the accumulation of ß-amyloid proteins, ALS, Parkinson’s, Dementia, Huntington’s, and Cardiovascular disease.
One study looked at sauna use in healthy Finnish men and found there was a 66% risk reduction in dementia and 65% risk reduction of Alzheimer’s disease when sauna bathing 4-7 times per week compared with subjects having 1 sauna session per week (2). This study only looked at one nationality and one gender, however, that’s a huge risk reduction! Another study, again looking at Finnish men found a 50% reduction in death from Cardiovascular disease and a 40% risk reduction in all-cause mortality in men using the sauna 4-7 times per week for 20 minutes or more around 79 degree Celsius. Even just using the sauna 2-4 times per week reduced the risk of all-cause mortality by 40% (6).
With the many benefits of increasing certain HSPs in the body, it should come as no surprise that having more HSPs actually increases your lifespan. And humans that have a specific genetic variation that makes them have more HSPs regardless of heat exposure are more likely to live past 100!
Since the beginning of January, I have been using the sauna 3-4 days per week for 10 minutes after my workout in the morning. I have found a noticeable increase in stress tolerance, as well as changes to my mood, focus, alertness, overall fatigue and a huge reduction in anxiety. All of these benefits could also have been attributed to the exercise that preceded the sauna session. Nonetheless, it is quite enjoyable and combined with all these other benefits, it’s safe to say it’s a habit I don’t think I can now live without! Try a month yourself, and see how you feel!
Ferris, T. (2014). Are sauna the next big performance enhancing “drug”? Retreived from http://tim.blog/2014/04/10/saunas-hyperthermic-conditioning-2/
Laukkanen, T., Kunutsor, S., Kauhanen, J. & Laukkanen, J.A. (2017) Sauna bathing is inversely associated with dementia and Alzheimer’s disease in middle-aged Finnish men. Age Ageing, 46(2), 245-9.
Charmpilas, N., Kyriakakis, E. & Tavernarakis, N. (2017). Small heat shock proteins in ageing and age-related diseases. Cell Stress Chaperones, Jan 10 doi: 10.1007/s12192-016-0761-x. [Epub ahead of print]
Leak, R.K. (2014). Heat shock proteins in neurodegenerative disorders and aging. J Cell Commun Signal 8(4), 293-310.
Paddock, C. (2015, October 13). "New Alzheimer's treatments may arise from modeling 'heat shock proteins'." Medical News Today. Retrieved from http://www.medicalnewstoday.com/articles/300878.php.
Laukkanen, T., Khan, H., Zaccardi, F. & Laukkanen, J.A. (2015). Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA intern med, 175(4), 543-8.
