Long before the advent of medicines and advanced therapies, man looked to nature for the answers to some of his most troubling health concerns. One of these is bathing in mineral-rich waters or hot or mud springs. While the term balneotherapy is relatively new, the practice of immersing one’s body in mineral-rich waters and hot springs has been going on since the 9th century BC and perhaps even earlier. And while there are now increasing numbers of scientific literature exalting the many benefits of balneotherapy including dermatologic, metabolic, and chronic musculoskeletal health, one question remains: can balneotherapy boost your immune system?
Before we can answer this question, it is important to understand the basic principles behind the practice of balneotherapy or simply the process of bathing in a specific type of water. These can include the use of hot or cold water, the presence of certain minerals, the application of massage, and the goal of either relaxing or stimulating the body.
Majority of those who undergo balneotherapy do so using hot springs that are typically rich in minerals like sulphur, selenium, and radium. The effects of hot water in the body are one of dilatation and relaxation. When heat is applied, the blood vessels increase in diameter allowing blood to flow more efficiently.
Science now shows that head-out, whole-body immersions in warm or hot baths can increase the total number of cytotoxic or killer T-cells, known as CD8+ lymphocytes, as well as natural killer (NK) cells. Cytotoxic (CD8+) T-cells are important in the neutralisation or killing of cancer cells and cells that are infected by viruses as well as those cells that are damaged through other processes. Natural killer cells, on the other hand, are important in the rejection of virus-infected cells and tumour cells. What this means is that immersing one’s body in hot water can help improve the function of these immune system cells that have specific roles in cancer and viral infection management.
For individuals who use cold water for balneotherapy, the effects are generally the opposite of hot immersions. The blood vessels decrease in diameter, making the blood to flow a lot faster as a means to compensate for the perceived reduction in the volume of blood. This can lead to an increase in heart rate and blood pressure.
As for its effects on the immune system, science reveals that cold water whole-body immersions, albeit briefly, can lead to an increase in lymphocytes, granulocytes, monocytes, and natural killer cells. We have already mentioned the role of natural killer cells in cancer cell and virally-infected cell management. Lymphocytes are important in the release of antibodies and the killing of infected cells. Monocytes produce cytokines, present antigens to antibodies so they can be inactivated or killed, and engulf and destroy pathogens themselves. Granulocytes contain substances that are toxic to microorganisms, thus killing them.
It is further noted that, if cold balneotherapy is to be observed daily for up to 6 weeks this can lead to an increase in tumour necrosis factor-α and interleukin-2. Interleukin-2 helps regulate the various activities of leukocytes or white blood cells. Tumour necrosis factor-α is typically a product of macrophage activation. It can also be brought about by stimulation of the other cells of the immune system such as eosinophils, CD4+ lymphocytes, neutrophils, and mast cells. In other words, TNF-α regulates the different cells of the immune system while also inhibiting the formation of tumour cells and the replication of viruses.
That being said, it is safe to say that cold balneotherapy can potentially lead to an enhancement of immunity against tumours.
While it is true that one can achieve similar results using conventional cold water or warm water immersions, one should not forget the other component of balneotherapy – minerals. These minerals can have a host of physiologic effects that can also translate to an overall improvement of the immune system.
Sulphur, for instance, is well-known for supporting the proliferation of T-lymphocytes while also protecting the body against oxidative stress. Selenium is also a very potent antioxidant which can further enhance the function of the immune system.
The combined effects of either hot or cold water and the addition of antioxidant and immune-boosting minerals should help improve one’s immune system.