There are multiple scientific studies showing whole body cryotherapy increases the number of white blood cells, T cells, and specific cancer killing immune cells called cytotoxic T lymphocytes.  In addition, a healthy stock of immune cells that remain active only when necessary, is correlated with living to ages of 100 plus years. 

Furthermore, studies have shown that three minutes in a cryo-sauna anywhere from 10 - 20 days in a row increases antioxidant levels from 36% to 100% in young men.  This is additional evidence that indicates cryotherapy has the ability to improve immunity.

In addition to improving important immune functions, cold exposures have a beneficial effect on oxidative stress. Reactive oxygen species (ROS), contribute to the process of ageing by contributing to DNA damage, cellular senescence, and mitochondrial dysfunction. Improving levels of antioxidants can be extremely important to staying healthy through preventing that damage from occurring or being able to repair it after it does occur. 

Exposure's to cold have been shown to activate potent antioxidant systems through hormetic stress, which are much more powerful than supplemental antioxidants.  Specific antioxidants including glutathione reductase, superoxide dismutase, and glutathione peroxidase have been shown to increase in activity from 43-68% following daily cold exposures up to 20 days!

Superoxide dismutase is extra important as it cleans up damage that is produced in our mitochondria that damage that is being produced every second of every day. Another important note, the participants in these studies showed higher expression of these antioxidants after each cryotherapy session, meaning the more consecutive sessions that were administered, the more benefit was achieved!