The Ten · Water
Water is a remedy most people never take seriously.
It is simple, it is free, and most people do not get enough of it. Drinking enough water, and using water on the skin, supports the body in more ways than most of us realize.
Book a Consultation →What This Is
Water means two things here. The first is drinking enough clean water through the day. The second is the old practice of using water on the body, warm and cold, to move the blood, settle the nerves, and ease aches. The first has good evidence behind it. The second has less, and the research section below says how much.
What the research shows
Mild dehydration is common, and it is not harmless.
Mood. Researchers at the University of Connecticut dehydrated healthy young women by about 1.4% of body weight, a level you can reach in an ordinary day without feeling thirsty. Their mood dropped, concentration fell, tasks felt harder, and headaches increased. Their scores on thinking tests mostly held up (Armstrong, J Nutr 2012). In the companion study in men, the same mild dehydration brought more tension and fatigue and small errors on attention and working-memory tasks (Ganio, Br J Nutr 2011). Both studies were small, and both were partly funded by a bottled-water company. The finding fits what most people notice in themselves by mid-afternoon.
Stress. When the body is short of water it releases vasopressin, the hormone that tells the kidneys to hold on to fluid. Vasopressin also nudges the brain's stress system. In 2025 a team in Liverpool compared adults who habitually drank about 1.3 liters a day with adults who drank about 4.4, then put both groups through a standard public-speaking stress test. Only the low drinkers showed a clear rise in cortisol, and the more concentrated a person's urine had been that week, the bigger the rise (Kashi, J Appl Physiol 2025). This was 32 people on one day, and it did not test whether drinking more calms the response. It is a lead, and only that.
Blood sugar. The same hormone is linked to diabetes risk. A group in Lund, Sweden, took adults who drank little and had high vasopressin markers, and had them add 1.5 liters of water a day for six weeks. The marker fell, and fasting glucose came down a little with it (Enhörning, J Clin Endocrinol Metab 2019). That was a pilot of 31 people. The large randomized trial that will settle the question is still underway.
Weight. In a 12-week randomized trial, overweight adults aged 55 to 75 on a reduced-calorie diet were told to drink two cups of water before each meal. They lost about 2 kg more than those on the same diet without the water (Dennis, Obesity 2010). The effect seems to come from eating a little less at each meal. It is an easy habit to start.
The heart. The Adventist Health Study at Loma Linda followed more than 20,000 Californians for six years. Men who drank five or more glasses of water a day had about half the rate of fatal heart disease of men who drank two or fewer, and women about 40% less. Other fluids did not show the benefit. The likely reason is that dehydration thickens the blood (Chan, Am J Epidemiol 2002). This is observational, and no one has repeated it in another population, so it cannot prove cause. It still gives me pause every time I let a day go by on coffee alone.
Water on the skin. Hot and cold water treatments have a long history in medicine. The evidence behind most of them is thin: small studies, old studies, or none. The one large modern trial I know of asked 3,000 Dutch adults to end their daily shower with 30 to 90 seconds of cold water for a month. They were sick just as many days as the control group, but they took 29% fewer sick days off work, apparently because they felt more able to carry on (Buijze, PLoS One 2016). Warm baths before bed help some people fall asleep sooner, and a cold cloth on the forehead helps some headaches. These are gentle, low-risk things to try.
How I use it
For most people the first step is to drink more water and to drink it on a schedule, before thirst arrives. Thirst lags behind need, and by midlife it is a poor guide. A glass on waking, a glass before each meal, and a bottle within reach through the day covers most of it. Pale urine is the simplest check.
From there we may add simple water treatments, warm, cold, or alternating, where they fit your situation. Amounts and approaches vary from person to person. Some heart and kidney conditions call for care with fluids, and some medications change what is safe, so we look at your labs and your prescriptions before changing anything.
What is possible
Water lets everything else work: clearer thinking, a calmer stress response, a little less appetite, and blood that moves the way it should. It costs almost nothing.
Where This Leads
Water is the quiet partner of every other remedy here. Good food, exercise, and sleep all go better when you are well hydrated.