Our cells need water to transport proteins and enzymes to nerve endings. Water also acts as adhesive material between cells and transports sugars for energy. If the body becomes dehydrated, a water-rationing process kicks in. The brain is first in line to receive available water, followed by the kidneys and liver. After that, it’s every organ for itself. In fact, dehydration may be a cause of many types of degenerative diseases, like asthma, arthritis, hypertension, angina, diabetes (type 2), lupus and multiple sclerosis.

How is it possible that wealthy Western people are dehydrated? It turns out that most of what we drink—tea, coffee, soft drinks and alcohol—dehydrates the body. Coffee and alcohol in particular rob our bodies of fluids, which explains the dry throat we experience after a pub crawl and the advice we hear to drink a glass of water for every cup of coffee. According to the prevailing wisdom, a dry throat alone is not a good indicator of thirst. The body lets us know we’re thirsty by creating pain. Dehydration may be at the root of many sicknesses, and dehydration can be avoided.

Under normal circumstances, everyone loses a gallon of fluids a day. In order to replenish the supply, we have to drink some 80 percent of that (20 percent of the needed water generally comes from what we eat). Don’t wait until we’re thirsty, we are advised. Thirst, after all, is a sign that our bodies are experiencing an acute water shortage. Drinking more water may be an inexpensive and painless way to safeguard our health.