Water

 It is said that water is the ideal drink for the human being, and that drinking

water is good for one’s health. The reasons why this would be the case, however,

are rarely stated. As a consequence, water, as a drink, is often neglected as a

factor in health.

THE BODY’S WATER CONTENT

Although the body is constructed of both liquid and solid materials, fluids are

present in much greater quantity than solids. Physiology teaches us that water is

actually the most important constituent of the body, accounting for 70 percent of

the human body’s composition.

    .

TABLE 1.1

THE BODY’S WATER CONTENT BASED ON AGE

Age Water Content (%)

4-month fetus 93

7-month fetus 85

newborn 80

child 75

Adult 70

Elderly person 60.

High and Low Blood Pressure

The body’s blood volume is not enough to completely fill the entire set of

arteries, veins, and capillaries. Regions of the body in which requirements for

blood are not very high will therefore supply some of it to regions whose needs

are greater.

For example, when we eat, the digestive tract has a greater need to be well

irrigated than the muscles of the legs, which are idle at the time. The blood

vessels of the legs therefore contract and expel some of their blood toward the

vessels of the digestive tract. These vessels then dilate to take in the extra blood

they need. The vasoconstricting and vasodilating capabilities of the vessels allow

the body to make adjustments that are crucial for its proper functioning.

However, these capabilities can be used in exaggerated ways, which can result

in health problems. Among other things, when the body deals with too little

blood volume caused by chronic dehydration, the blood vessels sharply contract.

This ensures that the volume of blood available—already limited in normal

circumstances, but now even more so because of dehydration—sufficiently fills

the vessels without leaving free spaces where pockets of gas could form.

But this defensive vasoconstriction can become permanent if the body is

suffering from a chronic liquid deficiency, and the result is chronic high blood

pressure. The increase of tension in the walls of the veins is exacerbated by a rise

in blood viscosity. The body is compelled to raise the pressure with which it

pushes the blood through the veins to compensate for the slowdown in

circulation caused by the increased thickness of the blood.

While dehydration can in some cases be responsible for high blood pressure, it

can also encourage the opposite condition, low blood pressure. If hypertension is

characteristic of people whose vessels have good tone and contract easily, low

blood pressure afflicts those whose vascoconstricting capabilities are weak.

Their blood pressure is lower than average because their blood is circulating

though vessels that are not tight and narrow.

When a person with low blood pressure becomes dehydrated, the blood

volume shrinks, but the vessels cannot reduce their diameter sufficiently to

compensate for the lower blood volume. The blood is thus circulating in slack,

poorly filled vessels, and the pressure falls even lower.

WATER

Drinking water is never pure in the chemical meaning of the word. Water that is

composed exclusively of two hydrogen atoms and one oxygen atom (H2O) can

be created only in the laboratory. Generally, water contains mineral salts that it

has captured while traveling underground. Drinking water is not a uniform

substance that always has the same composition wherever it is found. To the

contrary, its mineral content and consequently its character (its taste, its odor)

vary according to its provenance.

There are many different kinds of water, but they can be separated into four

major groups.

1. Odorless, tasteless waters. These are the purest waters, whose mineral

content is quite low. Evian water, for example, is the benchmark used by

professionals in the bottled water industry.

2. Odorless waters that have taste. These are the classic spring waters.

Minerals like calcium, magnesium, or sodium confer a slight flavor. The

extreme example is Vichy Celestin water, which has a very pronounced

salty flavor because of its high sodium content.

3. Waters with odor and no taste. These are also classic spring waters. In

contrast to the waters of the second group, they contain minerals like sulfur

that give them a strong and characteristic odor. These waters are not sold

commercially but are available directly from the spring at the thermal spa.

4. Waters that have taste and odor. This is tap water; the presence of

chlorine gives it both odor and taste.

Keep hydrated in this summer