According to new research, a hot bath could have effects that extend beyond the mental relaxation it can bring us. According to the authors, regular hot baths could reduce inflammation and improve metabolism. In recent years, hot baths, saunas, and other passive heating therapies have received increasing attention from scientists.
Scientists now believe that hot baths offer some potential benefits, including improved vascular function and sleep .
Because hot baths are inexpensive and unlikely to cause significant side effects, understanding any benefits it may have could be a quick win for medicine.
Recently, a team of researchers set out to understand whether soaking in a hot bath could have an impact on metabolic disorders, such as diabetes. They theorized that the influence of a hot bath on glucose metabolism could revolve around the inflammatory response.
There is some evidence that chronic low-level inflammation increases insulin resistance. In other words, inflammation reduces a cell’s ability to respond to insulin, potentially contributing to the development of diabetes.
Conversely, exercise has been shown to reduce inflammation and improve insulin sensitivity, which means that the body has better control over glucose levels.
Although doctors often recommend exercising to reduce the risk of developing metabolic disorders, not everyone is able to exercise, perhaps due to health conditions or physical ability. Therefore, it is essential to find alternative ways to improve insulin sensitivity for these people.
Exercise elicits a brief inflammatory response, followed by a more extensive anti-inflammatory response. The researchers wanted to see if a different type of physical stress (a hot bath) could have a similar effect on the immune system.
For this study, experts examined the impact of a hot bath on overweight, mostly sedentary, men . Each participant was immersed in a 39 ° C water bath for 1 hour. Blood samples were taken just before and after the bath, and then 2 hours later. In addition, they recorded the participants’ blood pressure, body temperature, and heart rate every 15 minutes.
Over the next 2 weeks, the participants had another 10 dives in hot water.
The researchers found that a single soak in hot water caused an increase in interleukin, a marker of inflammation. Similarly, there was an increase in nitric oxide production.
The increase in nitric oxide is important because it causes the blood vessels to relax, lowering the blood pressure. It also improves glucose intake in tissues, and scientists believe it has anti-inflammatory properties.
As expected, the 2-week intervention saw a reduction in fasting blood sugar and inflammation. In the same way that exercise influences inflammation, the researchers saw an initial increase followed by a long-term decrease in inflammation.
“Immersion in hot water may improve aspects of the inflammatory profile and improve glucose metabolism in sedentary, overweight men ,” the authors conclude in the Journal of Applied Physiology .
The researchers also note that “it could have implications for improving metabolic health in populations that cannot meet current physical activity recommendations.”
Could shorter periods or lower temperatures have similar benefits? It will have to be investigated.
Reference: Acute and chronic effects of hot water immersion on inflammation and metabolism in sedentary, overweight adults. Journal of Applied Physiology . SP Hoekstra, NC Bishop, SH Faulkner, SJ Bailey, and CA Leicht. https://doi.org/10.1152/japplphysiol.00407.2018
