Hydration – it’s all about the stress (or lack of it)

A Stanford radiologist recently published an interesting article in the journal Medical Hypotheses. The title sums up the basic premise:

Clinical benefits of hydration and volume expansion in a wide range of illnesses may be attributable to reduction of sympatho-vagal ratio

One of the most common things patients tell me on their own is that they do not drink enough water. They are likely right, as simple hydration improves symptoms in a wide variety of conditions, and often speeds recovery as well. IV or oral hydration has many wide-ranging benefits, but the authors of the above article believe that the benefits can all be attributed to a reduction in stress.

Simply put, the premise is that if you are marginally dehydrated, certain pressure and volume sensors (baroceptors) cause an increase in the tone of the sympathetic, fight-or-flight nervous system, along with a cascade of hormones that aim to retain fluid; unfortunately these same hormones contribute to the “stress response”.

Keeping well-hydrated avoids this increased stress bias in the autonomic nervous system. The stress bias is important in a variety of diseases. In the authors’ own words:

“Emerging evidence suggests that many diseases including cardiovascular, neurologic, gastrointestinal, metabolic, inflammatory, thrombotic, viral, and oncologic conditions are manifestations of abnormal sympathetic bias and associated T helper 2 bias.”

We already know that proper hydration helps decrease the viscosity of blood in cardiovascular patients, dilutes toxins in cancer patients, and helps excretion for patients undergoing a detoxification. And many patients have suggested that proper hydration makes them “feel better” – undoubtedly proper hydration makes patients feel better (and healthier) because of a decreased “stress-bias” in their autonomic nervous system. Remember, the autonomic nervous system has a large influence on how all the organs and tissues function.