Alexa Fleckenstein, M.D., author of Health20, has a few things to say about cold showers. Within the book, she writes:

“Cold water can do more than just wash away sweat, dirt, old skin cells, bacteria, and viruses:

What a Cold Shower Can Do For You

1. Enhance immunity against infections and cancer

2. Give your glands (thyroid, adrenals, ovaries/testes) a boost, improving hormonal activity

3. Jump-start your mood and motivation

4. Crank up your metabolism to fight type 2 diabetes, obesity, gout, rheumatic diseases, depression, and more

5. Normalize your blood pressure

6. Decrease chronic pain

7. Train and improve your blood circulation

8. Detoxify your body

9. Fight fatigue

10. Strengthen exhausted, irritable nerves

11. Rejuvenate, heal, and tone the skin

12. Deepen your breathing

13. Help with insomnia

14. Improve kidney function

15. Reduce swelling and edema

16. Improve lymphatic circulation, thereby increasing immune function

17. Reduce stress by regulating your autonomic nervous system

18. Regulate temperature, fighting chronically cold hands and cold feet and excessive sweating

19. Keep your hair healthy

20. Improve hemorrhoids and varicose veins

21. Reduce aches and pains”

Just thought you’d like to know.

Once again, studies show at least some support for the popular wisdom. An experiment in Prague studied the effect of cold water immersions on athletic young men. They immersed them in water at 14 °C (57 °F), three times a week for six weeks. They concluded that the immersions activated the immune system “to a slight extent”.

Among many changes, they saw increased levels of two types of white blood cells: monocytes and lymphocytes. While certain lymphocytes are instrumental in eliminating bacteria, viruses, and toxins, monocytes are indirectly responsible for the engulfing and consuming of pathogens and foreign materials [2,3].

Considering these effects, it’s no surprise that mice exposed to 8 days of brief cold water stress survived significantly longer when exposed to the intracellular parasite, Toxoplasma gondii [4].

So, cold showers can help keep away the sniffles, but who knows what other nasty virus or pathogen you might also happen to ward off?

[1] Immune system of cold-exposed and cold-adapted humans.
[2] http://en.wikipedia.org/wiki/Lymphocyte
[3] http://en.wikipedia.org/wiki/Monocyte
[4] Cold stress-induced modulation of cell immunity during acute Toxoplasma Gondii infection in mice.