Selected Reading

BOOKS

A selection of books, articles and other materials to better understand Human Hydration from a scientific perspective. This selection has been conducted by our SAB members.

• Hydration Throughout Life. Ed: MJ Arnaud. John Libbey Eurotext, London
• Hydration and Aging. Ed: MJ Arnaud et al. Springer, New York. 1998
• Sports Drinks: Basic Science and Practical Aspects. Ed: RJ Maughan and R Murray. CRC Press, Boca Raton. 2001
• Thirst and Sodium Appetite: Physiological Basis. Ed: SP Grossman. Academic Press, San Diego. 1990
• Body Fluid Balance. Ed: ER Buskirk, SM Puhl. CRC Press, Boca Raton. 1996
• Water Science for Food Health. Ed: Z Berk et al. CRC Press, Boca Raton. 2001
• Thirst. Ed: BJ Rolls and ET Rolls. Cambridge University Press, Cambridge. 1982

ARTICLES

Water, hydration, and health.

Popkin BM, D’Anci KE, Rosenberg IH. Water, hydration, and health. Nutr Rev 2010; 68(8): 439-58.

This review examines the current knowledge of water intake as it pertains to human health, including overall patterns of intake and some factors linked with intake, the complex mechanisms behind water homeostasis, and the effects of variation in water intake on health and energy intake, weight, and human performance and functioning. Water represents a critical nutrient, the absence of which will be lethal within days. Water’s importance for the prevention of nutrition-related noncommunicable diseases has received more attention recently because of the shift toward consumption of large proportions of fluids as caloric beverages. Despite this focus, there are major gaps in knowledge related to the measurement of total fluid intake and hydration status at the population level; there are also few longer-term systematic interventions and no Con formato: Numeración y viñetas Con formato: Numeración y viñetas published randomized, controlled longer-term trials. This review provides suggestions for ways to examine water requirements and encourages more dialogue on this important topic.

Water as an essential nutrient: the physiological basis of hydration.

Jéquier E, Constant F. Water as an essential nutrient: the physiological basis of hydration. Eur J Clin Nutr 2010; 64(2): 115-23

How much water we really need depends on water functions and the mechanisms of daily water balance regulation. The aim of this review is to describe the physiology of water balance and consequently to highlight the new recommendations with regard to water requirements. Water has numerous roles in the human body. It acts as a building material; as a solvent, reaction medium and reactant; as a carrier for nutrients and waste products; in thermoregulation; and as a lubricant and shock absorber. The regulation of water balance is very precise, as a loss of 1% of body water is usually compensated within 24 h. Both water intake and water losses are controlled to reach water balance. Minute changes in plasma osmolarity are the main factors that trigger these homeostatic mechanisms. Healthy adults regulate water balance with precision, but young infants and elderly people are at greater risk of dehydration. Dehydration can affect consciousness and can induce speech incoherence, extremity weakness, hypotonia of ocular globes, orthostatic hypotension and tachycardia. Human water requirements are not based on a minimal intake because it might lead to a water deficit due to numerous factors that modify water needs (climate, physical activity, diet and so on). Water needs are based on experimentally derived intake levels that are expected to meet the nutritional adequacy of a healthy population. The regulation of water balance is essential for the maintenance of health and life. On an average, a sedentary adult should drink 1.5 l of water per day, as water is the only liquid nutrient that is really essential for body hydration.

Hydration in children.

Manz F. Hydration in children. J Am Coll Nutr. 2007; 26(5 Suppl): 562S-569S.

Water supply is a basic public problem. In modern science, three periods with different approaches to define recommended water intake in adults can be distinguished. Pediatricians agree that hydration in children may be optimal only in breastfed infants. More data are required on the health effects of different hydration states and varying water intakes in particular age and gender groups to define optimal ranges of water intake. The fetus grows in an exceptionally well-hydrated environment. Water metabolism shows several peculiarities in preterm and term infants. Infant diarrhea remains a major topic of basic and clinical research. Water intoxication in infants, toddlers, and children is rare and can only be found in exceptional circumstances. Hydration status characterized by hyponatremia may play a role in the pathogenesis of febrile convulsions in toddlers. There is increasing indirect evidence that spontaneous drinking behavior of a population may be fixed and anchored in the age range of toddlers. Sex differences in hydration status are common, but not obligatory. What causes theses differences? What is behind the various circadian rhythms of urine osmolality in children? At what age and in what quantities can alcohol and caffeine consumption be tolerated? How can individual susceptibility be defined? Reflecting on the modern epidemic of obesity in children and adolescents, a public consensus concerning use and misuse of sweetened drinks seems mandatory. Dietary reference intakes of water refer to 24-hour intake. In nutritional counselling, food and mealbased dietary advice is primarily given. Young parents are confronted with a flood of advice of varying quality. Recommendations on fluid consumption should be collated and revised.

Free article in PubMed

HYDRATION EDUCATIONAL MATERIALS

Hydration: Fluids for Life