By CARLTON MOELLER
When you think about saunas, what’s the first thing that comes to your mind? For many, it’s relaxation, spas, or sweating. But there’s a lot more to them than that. While in the sauna, though it may feel completely relaxing, it’s actually a workout. During sauna use, your heart rate can reach up to 150 beats per minute. When you think about it, it makes sense—your body has to work hard to keep you from overheating. Considering this, it’s not surprising that regular sauna use is linked to improved cardiovascular health.
A recent study published in the Journal of Internal Medicine in 2015 investigated 2,000 middle-aged men from Finland—where sauna use is heavy—and compared frequency of sauna use with cardiovascular health and all-cause mortality, including cancer, over 20 years. The study found that fatal cardiovascular disease was 27 percent lower for men who used the sauna two to three times per week, and 50 percent lower for those who used the sauna four to seven times a week, as compared to those who used it only once a week.
In addition, they found that the two to three times per week group had 24 percent lower incidents of all-cause mortality and the four to seven times per week group had a 40 percent decrease. These results are profound, but why? How can relaxing in a hot room improve one’s longevity by such a remarkable amount? There are two molecular explanations: heat shock proteins and the gene foxo3.
When your body heats up, it releases heat shock proteins. Heat shock proteins function to keep the rest of the proteins in your cells structured in their proper 3-dimensional shape when under stress. They protect your cell’s proteins not only from heat stress, but from all other stressors that might damage a cell’s proteins, like ultra-violet radiation from the sun or the process of aging. Even regular immune function and metabolism create wear on the proteins of your cells through the production of reactive oxygen and nitration species. As we age, our proteins accumulate damage through a process called protein aggregation. Protein aggregation is associated with heart failure, cardiomyopathy, atherosclerosis, Alzheimer’s, Parkinson’s, and Huntington’s disease. Heat shock proteins help prevent protein aggregation and have also been shown to protect against neurodegenerative diseases.
In addition to heat shock proteins, the gene foxo3 is also associated with increased longevity and saunas. People with a polymorphism in their DNA, which is a difference in the nucleotide sequence that creates more foxo3, have a 2.7 fold increased chance to live to 100. Foxo3 is a master regulator of many other genes, and when it is activated by sauna use, it increases the expression of different genes, making you more resilient to the multiple types of stress that occur with aging. It also protects against DNA damage, which is a major cause in the production of cancerous cells. Foxo3 protects your DNA from the same reactive oxygen and nitration species that damage your proteins as well. Foxo3 increases the expression of antioxidant genes, which are more potent than antioxidants obtained through one’s diet. Foxo3 has various other health advantages, including increasing the expression of genes involved in immune function.
The health benefits from saunas seem too good to be true, so why don’t more people use them? There’s no way to explain how great you feel after using a sauna. 20 minutes of using a sauna can give you a euphoria stronger than running four miles can. After sweating profusely through all the pores in your body, you can be left with this unmatched feeling of cleanliness in your skin, as if it has been washed from the inside out.