Everybody knows that pure good old fashioned water is good for you. Water is 2/3 of the body weight of most humans and is essential for normal cellular function. Researchers have found that water is so much more than just taking up cellular space. The effects can be subtle and very beneficial.
You’ve probably heard before that drinking water before a meal can help you lose weight. The working theory was that the water made you less hungry both by quenching your thirst and taking up room in your stomach. The truth is much more interesting! It turns out that drinking water actually speeds up the metabolism just a little bit. While this was first observed in a study several years ago, a new study tells us why: “It increases the activity of the sympathetic – fight or flight – nervous system, which raises alertness, blood pressure and energy expenditure.” Researcher Julia McHugh says “I calculated it might be as much as five pounds a year [of weight loss] if you drank three 16 ounce glasses of water a day and nothing else changed. This is not going to be the answer to the weight problem in the United States, but it’s interesting that activation of the sympathetic system is enough to do that.”
McHugh was able to trace the results down to a particular protein called Trpv4, which is thought to regulate osmosis in the body.
Several very interesting things happen as a result of this. First, it means that just drinking a glass of water can make you just a little more alert, regardless of whether or not caffeine is involved. Second, drinking a full pint of water before giving blood reduces the chances of fainting by 20%! As Dr. David Robertson points out, “If you pass out after giving blood, you pretty much never give blood again. If we can reduce fainting by 20 percent, we can reduce the unpleasantness of passing out and really bolster the number of people who can continue to be blood donors.”
Despite the effect on blood pressure, most people with hypertension shouldn’t worry about cutting down on water. It’s only a problem for people with an impaired baroreflex function, which means the normal systems that should keep blood pressure in a normal range don’t work properly.