The importance of hydration older people

Water is one of the main nutrients in the body, a major component of the human body, involved in many body functions and essential in all stages of life. As they age, mechanisms responsible for water balance can be altered, that is why there is a greater risk of dehydration.

What is dehydration?

 Dehydration is the reduction of water content total body fluid loss, decreased fluid intake, or a combination of both. In addition, according to the EFSA (European Food Safety Authority), it can be of three types:

• Isotonic dehydration: you lose as much water as sodium, for example in the case of diarrhea.
• Hypertonic dehydration: There is a greater loss of water than sodium, for example, in the case of fever.
• Hypotonic dehydration: greater loss of sodium than of water, for example, in the case of excessive use of diuretics.

Changes in physiology due to age that influence water balance

Total body water content

As you age, your total body water content is reduced as there is a lower lean body mass (muscle) and a higher percentage of body fat (tissue with low water content). It is estimated that the total body water content can be reduced from four to six liters from 20 to 80 years (Gille 2010). Therefore, small losses of body water or not drinking enough can cause with easier dehydration.

Feeling thirsty

The feeling of thirst tends to decrease in older people, which may mean less fluid intake. It is not known exactly what can cause the decreased feeling of thirst, although it is believed that it may be due to a reduction in dopamine, a neurotransmitter that participates in the induction of thirst and the increase in plasma of PNA (atrial natriuretic peptide), a thirst inhibitor. Due to this poorer thirst regulation, older people often do not drink enough and often do not hydrate properly.

Renal function

The very deterioration of the kidneys' ability to conserve water is a consequence of aging. The kidneys are less able to concentrate urine and retain water when necessary. In addition, there is a lower response of the kidneys to anti-diuretic hormone (ADH) and a limitation in the excretory capacity of the kidneys.

Other factors

Aging can lead to limitations such as reduced swallowing ability, reduced mobility or comprehension and communication disorders that can lead to insufficient fluid intake, as well as diseases or symptoms, such as diabetes or those that can increase water losses . Environmental factors such as high temperatures, humidity ... or medication can increase the risks of possible dehydration.

Symptoms of dehydration

The symptoms of dehydration are organized according to their severity: mild or moderate and severe:

• Mild or moderate dehydration: thirst, muscle cramps, headache, lack of elasticity in the skin, little urine, drowsiness and tiredness.
• Severe dehydration: not urinating, rapid breathing, dry and wrinkled skin, confusion, dizziness, increased heart rate, and sunken eyes.
• Very serious: insufficient blood flow, hallucinations and unconsciousness.

Consequences of dehydration in the elderly

Current evidence suggests that dehydration can cause:

• (It is the main consequence of dehydration).
• Alteration of cognitive functions.
• Falls
• Postural hypotension (is a form of low blood pressure that occurs when you stand up after sitting or lying down).
• Salivary gland dysfunction (poor saliva production).
• Poor control of hyperglycemia in diabetes.
• Urinary infection.
• Kidney stones

Prevention of dehydration

The prevention of dehydration in the elderly is mainly based on ensuring correct dehydration. The awareness of the elderly, their families and their caregivers regarding the severity of dehydration and its risk factors is essential. It is important to adapt to the elderly, considering individual risks (medication, incontinence ...) and environmental (humidity, temperature ...) to achieve optimal hydration.

Liquid intake recommendations for the elderly

Daily water needs depend on several factors, such as fluid losses, ambient temperature, taking medication or certain pathologies, etc. That is why many countries do not give a national recommendation on water intake, or there is a lot of variation from one country to another. In Europe, the European Food Safety Authority recommends that the reference value for total fluid intake (water from beverages and food) be 2.5 l and 2 l for older men and women, respectively. For those elderly who find it difficult to drink water, they should have a diet especially rich in fruits and vegetables.

Strategies to Encourage Fluid Consumption

• Offer fluids regularly throughout the day
• Place fluids near, by the bed, or next to the elderly chair in nursing homes, throughout the day.
• Offer it in a comfortable way, with a glass, bottle, straw ... depending on the needs.
• Encourage the consumption of fluids with medication.
• Offer drinks that the person likes especially if they are healthy.
• Guarantee a minimum intake of 1.5 liters in periods of greatest risk of dehydration.

What kinds of liquids and foods can be offered?

In addition to drinking water as the main drink, fruits and vegetables should be part of the daily diet. Other valid options to hydrate are: consume broths, non-salty soups and milk, but always take into account the thermal and humidity conditions offering more water at higher figures. Coffee and tea can have a diuretic effect, so they should be consumed in moderation and not as a main drink. It is not recommended to drink alcoholic beverages.

Conclusions.

The degree of hydration of older people is the result of a fragile balance; therefore, it must be controlled in great detail. Constant attention must be paid, as dehydration can cause considerable clinical consequences.

• Water is the medium in which all the chemical reactions of the body take place, it acts as a nutrient transporter and as a vehicle to eliminate waste products, lubricates and provides structural support to tissues and joints, and has a fundamental role in the regulation of body temperature, essential to avoid dehydration.
• As we age, the total body water content is reduced as there is a lower lean body mass (muscle) and a higher percentage of body fat (tissue with low water content). It is estimated that the total body water content can be reduced by four to six liters from 20 to 80 years.
• In addition to drinking water as the main drink, fruits and vegetables should be part of the daily diet. Other valid options to hydrate are consuming broths, non-salty soups and milk.

Diploma in Human Nutrition and Dietetics

Master in Pediatric Nutrition