Given lifestyle and age variables, what is considered a healthy intake of water on a daily basis?
Water is the largest constituent of our body, and is involved in all its physiological reactions.
The recommendations for a daily intake of eight glasses of water probably came up from the need to have a guideline that emphasises the importance of sufficient water intake, but be easily understood by the public. Eight cups refer to un-caffeinated, non-alcoholic fluid, since these substances are natural diuretics that increase urinary loss of water. Thus taking eight cups of coffee does not result in the same water gain as drinking eight cups of water!
Variations from these recommendations exist. Being overweight necessitates more fluid consumption. Every 10kg a person is above the ideal weight roughly translates to an additional requirement of 240ml (another cup). In conditions of excessive sweating, water requirements rise drastically. We usually drink because we are thirsty but one has to appreciate that in some situations, thirst may not keep pace with the actual water requirement of the body.
Young children need more water per body weight for a variety of reasons, including their large surface area per unit of body weight. A female who is breastfeeding has also higher water requirements, which may amount to an additional 700ml/day.
Can a glass of milk substitute a glass of water?
Milk and water are both fluids, other than that they are completely different. I am an advocate of milk consumption. It is a good thirst quencher and a high source of nutrients. It is an excellent source of calcium, riboflavin and vitamin D. It is ideal for the growing child who needs lots of calories and calcium for growth. Its skimmed version is ideal for the elderly who depend more on dietary sources of vitamin D. So my recommendations are to drink milk, but to also continue to consume the two litres of water per day. After all water is the ultimate solvent.
Despite increasing awareness of the benefits of drinking sufficient amounts of water, many people still don't take the advice probably because old habits die hard. How would you encourage people to drink enough water on a daily basis?
The body has no provision for water storage. Therefore the amount of water lost every day must be replaced to preserve health. Loss of only 10 per cent of our body water causes severe disorders; loss of 20 per cent causes death. Chronic mild dehydration is associated with various complications such as diminished salivary gland function and an increased risk of kidney stones in some individuals.
The most vulnerable remain the very young and the very old. The gut can be a major source of water loss, especially during diarrhoea. The ability of the kidneys in older individuals to concentrate the urine may be compromised, resulting in increased risk of dehydration.
What are your views regarding water as a source of minerals?
As a general rule drinking water should not be considered a source of minerals. However, this does not mean that the water we drink will not contain minerals. Subjects who regularly drink mineral-rich water can have a calcium intake that is significantly higher than those drinking low-mineral-content water. The same applies for magnesium, where regular consumption of mineral water can contribute appreciably to one's magnesium intake.
Some decades ago a negative relationship between water hardness and cardiovascular mortality rate was demonstrated. This elicited a lot of interest in the scientific community regarding minerals and trace metals and the development of atherosclerosis. Scientists are to this day attempting to find a protective factor in hard water or a detrimental factor in soft water. The roles of calcium and magnesium have been considered possibly beneficial, whereas those of others such as cadmium and lead have been considered potentially harmful.
In normal circumstances how often are tests carried out to ensure the potable quality of water?
Specific laws regulate water. Water is treated for biological content before it is served to the public. As for bottled water, once the water is inside the bottle, the bottle is sealed and thus bacteria should not be able to get inside.
• Mr Magri is a registered nutritionist.
Water is the largest constituent of our body, and is involved in all its physiological reactions.
The recommendations for a daily intake of eight glasses of water probably came up from the need to have a guideline that emphasises the importance of sufficient water intake, but be easily understood by the public. Eight cups refer to un-caffeinated, non-alcoholic fluid, since these substances are natural diuretics that increase urinary loss of water. Thus taking eight cups of coffee does not result in the same water gain as drinking eight cups of water!
Variations from these recommendations exist. Being overweight necessitates more fluid consumption. Every 10kg a person is above the ideal weight roughly translates to an additional requirement of 240ml (another cup). In conditions of excessive sweating, water requirements rise drastically. We usually drink because we are thirsty but one has to appreciate that in some situations, thirst may not keep pace with the actual water requirement of the body.
Young children need more water per body weight for a variety of reasons, including their large surface area per unit of body weight. A female who is breastfeeding has also higher water requirements, which may amount to an additional 700ml/day.
Can a glass of milk substitute a glass of water?
Milk and water are both fluids, other than that they are completely different. I am an advocate of milk consumption. It is a good thirst quencher and a high source of nutrients. It is an excellent source of calcium, riboflavin and vitamin D. It is ideal for the growing child who needs lots of calories and calcium for growth. Its skimmed version is ideal for the elderly who depend more on dietary sources of vitamin D. So my recommendations are to drink milk, but to also continue to consume the two litres of water per day. After all water is the ultimate solvent.
Despite increasing awareness of the benefits of drinking sufficient amounts of water, many people still don't take the advice probably because old habits die hard. How would you encourage people to drink enough water on a daily basis?
The body has no provision for water storage. Therefore the amount of water lost every day must be replaced to preserve health. Loss of only 10 per cent of our body water causes severe disorders; loss of 20 per cent causes death. Chronic mild dehydration is associated with various complications such as diminished salivary gland function and an increased risk of kidney stones in some individuals.
The most vulnerable remain the very young and the very old. The gut can be a major source of water loss, especially during diarrhoea. The ability of the kidneys in older individuals to concentrate the urine may be compromised, resulting in increased risk of dehydration.
What are your views regarding water as a source of minerals?
As a general rule drinking water should not be considered a source of minerals. However, this does not mean that the water we drink will not contain minerals. Subjects who regularly drink mineral-rich water can have a calcium intake that is significantly higher than those drinking low-mineral-content water. The same applies for magnesium, where regular consumption of mineral water can contribute appreciably to one's magnesium intake.
Some decades ago a negative relationship between water hardness and cardiovascular mortality rate was demonstrated. This elicited a lot of interest in the scientific community regarding minerals and trace metals and the development of atherosclerosis. Scientists are to this day attempting to find a protective factor in hard water or a detrimental factor in soft water. The roles of calcium and magnesium have been considered possibly beneficial, whereas those of others such as cadmium and lead have been considered potentially harmful.
In normal circumstances how often are tests carried out to ensure the potable quality of water?
Specific laws regulate water. Water is treated for biological content before it is served to the public. As for bottled water, once the water is inside the bottle, the bottle is sealed and thus bacteria should not be able to get inside.
• Mr Magri is a registered nutritionist.