Diets-Metabolism   [back to the Category]

Water.   [read the french version]

Author :   Dr Paule Nathan

Life cannot exist without water, this precious element comes from food

Water is the main constituent of the body since an adult body is 60% water. It is essential to life. Although we can abstain from eating for several weeks without dying, we cannot survive for more than 72 hours without drinking water. This is how hunger strikers, providing that they drink water, are able to continue their action for many weeks.

Water requirements are determined by the amount of water lost through the skin, lungs, kidneys and stools. This amount varies according to room temperature (warm surroundings will mean an increase in requirements due to perspiration, theatres are often overheated), diet (a higher protein intake level requires an increased hydrous intake level) and physical activity. Requirements are estimated at 2.5 to 3 litres of water per day, half of this (around 1 litre) is provided by food and the other half (1 to 1.5 litres) by water in drinks. All food contains water in variable quantities. It varies from 0% (oil) to more than 90% (milk). In actual fact, we must drink so that we eliminate 1 litre and a half of water in urine. Man's hydrous intake level is controlled by thirst, an alarm signal that allows us to renew our water supplies. We should get used to drinking before being thirsty so that the dehydration indicated by thirst is avoided: or else watch out for fatigue or tiredness during exertion.

Water plays several roles:
- it optimises cell exchanges
- it participates in the regulation of body temperature
- it participates in the elimination of toxins, above all, participating in the prevention of an excess in the level of uric acid
- it allows the intestines to function better through stool hydration

The water circuit in the body is well established. When we drink water, it passes into the stomach where it is absorbed into the blood stream. The 70% water, contained in the body, undergoes pressure gradients which allow cell exchanges of electrolytes and nutrients. Thus, waste is evacuated. Water circulates between cells and is renewed via lymph ducts. The lymphatic system carries water to the heart.
The water circulates throughout the body, around the brain, the spinal cord, all the head organs, muscles, articulations, etc.

The hydrous balance permanently controls the hydrous stock.
We eliminate about 2.5 litres of water a day. This loss can be increased by a very hot climate or by demanding physical activity.
- 1 litre evaporates through the skin and lungs
- 1.4 is lost in urine
- 100 ml in stools
The daily intake level is estimated at 2.5 to 3 litres per day in order to assure body water replacement. Half is provided by food, the other half comes from the water that we drink.

Water content of some foods
(in % in relation to the total weight of the fresh food)
water: 100%
85 to 90% milk
80 to 90% fresh vegetables
80 to 85% fresh fruit
80% non-oily fish
70 to 75% meat
74% eggs
66% oily fish
50% soft cheeses
35% bread
35% hard cheeses
20 to 22% dried fruit
16% butter, margarine
6% biscuits
0% oils

There are waters to suit all tastes
@ Tap water.
Tap water can be considered as safe to drink. It is a drinking water, it is not harmful to the health and is controlled by strict organoleptic, physico-chemical and microbiological criteria. It should be clear, odourless, free of pathogenic germs and toxic substances. Do not worry, water is controlled at all stages of collection, storage and processing. It can, sometimes, have the disadvantage of a taste of chlorine especially in the summer. But, if you put the carafe of water in the refrigerator for a few hours, the taste fades
@ Bottled waters.
The alternative to tap water, is bottled water. Here, there are three different categories, drinking water, spring water and mineral water
- Drinking water. This is just an ordinary drinking water. It has, therefore, the same qualities as tap water. It has no taste and can be bottled as it is, or carbonated. It is then described as fizzy water. It is a pure water that does not contain any impurities.
It is a water that has been processed and disinfected and which must not have more than 50mg of nitrates per litre.
- Spring water.
This is collected and bottled at source. It is not processed in any way. It does not have any therapeutic qualities and everybody can drink it.
- Mineral water.
Its pharmacodynamic properties give this water therapeutic qualities. There are about 1200 mineral water sources. The water can either be bottled or used on site for water cures. These waters have been given approval for their "mineral water" designation and come under the control of the Ministry of Health and the National Laboratory for Public Health. The name of the source of production must obligatorily be on the label together with its composition and where it is sourced. European regulations forbid producers to sterilise their water if they wish to keep the "natural mineral water" designation. Purity controls are carried out frequently.
Mineral waters that have small amounts of minerals can be drunk on a daily basis, however, be careful with harder waters that have higher mineral levels as their richness can, in time, be harmful.

Beware of dehydration
Dehydration is caused by a lack of water intake. The first symptoms are fatigue, headaches, difficulty in concentration, tight skin and thirst; thirst being the signal for the start of dehydration. This is why we advise that you drink before you get thirsty. The thirst signal indicates dehydration already exists.
Severe dehydration results in a deterioration in the organs, mental aberration and a coma.