WATER  :  HOW MUCH AND WHY

 

Bhagat Sant Ravidas Ji has described the human body in beautiful quote. The description is included in Sri Guru Granth Sahib Ji and the holy scripture says,

“Jal kibheetpavanka khamba rakt boond ka gaara( Ang.659 )”

Literal translation means that the human body is constructed using ‘the walls of water and is supported by the pillars of air with blood drops acting as the binding cement mixture.’ This verse points towards the importance of water mentioned in ancient wisdom and spiritual texts. Science also acknowledges the contribution of water as one of the major constituents of body composition.Various studies point at water constituting 55% to 75% of total body composition. Source of water intake is through direct ingestion in simple form, as a part of a beverage or to some extent, through oxidation of macronutrients as metabolic water.

FLUID BALANCE IN THE HUMAN BODY

A human being cannot survive without waterafter a few days. Yet it is taken for granted.A healthy human body has a meticulous mechanism to maintain the adequate hydration. This mechanism ensures a coordination of strategically located sensitive detectors at different places in the body which are linked by neurological pathways (with integrative centers) in the brain that process the required information. These centers are sensitive to neurohormones or humoral factors produced for adjustments of diuresis, natriuresis and blood pressure. Along with these,some nerves convey instructions from integrative centers to the organs responsible for execution like kidneys, sweat glands, salivary glands and a part of the brain responsible for corrective action such as drinking fluids.

Fluid balance and its components are controlled by sensitive and precise mechanisms which get activated with deficits or surplus of water by a margin of a few hundred milliliters.

A suboptimal body water level or hypohydration or dehydration results in an increase in the ionic concentration of the extracellular compartment prompting it to draw water from intracellular compartment. This causes a shrinkage in cells which gets detected by two distinct brain sensors. One of these controls water intake. The other controls excretion of urine by sending a signal to the kidneys to produce less quantity of concentrated urine. In case of hyperhydration or presence of more than optimal water in the body, the opposite process happens. As the ionic concentration of body fluids diminishes, more water reaches intracellular compartments, leading to suppression of water intake. This increases the urine output through excretion.

HYDRATION AND ITS BENEFITS

The benefits of adequate hydration are numerous. Whereas, dehydration causes many complications. Let’s take a look at the areas which get affected due to dehydration.

  1. Body Temperature

The body keeps its temperature in control by a complex process. In hot and humid conditions or in phases of increased physical activity, the body releases water in the form of sweat through the skin. This prevents the body temperature to go further up. The evaporation of sweat leads to a cooling effect for the skin. The process is known as thermoregulation.

Dehydration or hypohydration happens when water intake is significantly lower than water loss happened through sweating. This is caused due to the drop-in water percentage in the body’s composition. Dehydration, in its mild form is associated with reduced plasma volume and increased plasma osmolality. This also results in an elevation in cortisol, increased or decreased sweating and Electrolyte imbalances.

  1. Physical Performance

Many athletes, during their training sessions do not maintain proper hydration. They do not drink adequate water even when guided by thirst.

All those who engage in rigorous physical activities with inadequate water intake, experience a deterioration in performance. This could result in reduced endurance, increased fatigue, reduced motivation and increased perceived effort.

The impact of hypohydration is more severe as far as high intensity aerobic and endurance activities (like tennis or long distance running) are concerned.

A long duration of physical exertion creates fluid deficiency in the body. If the voluntary fluid intake is inadequate to replenish this deficiency, this leads to mild to moderate dehydration for hours even after the conclusion of the physical activity.

Increased water intake for a prolonged period can reverse this condition. It also reduces oxidative stress induced by exercise and dehydration.

  1. Mood and Cognitive performance

Dehydration can disruptthe mood and the cognitive abilities as well. People residing in hot regions or those involved in high-intensity physical activity are often the victims of this condition.

Concentration, alertness, short-term memory, perpetual discrimination, arithmetic ability, visual-motor tracking, psychomotor skills are some of the areas that get impaired in varying degrees, due to dehydration. The commonly reported ones are- elevation of subjective mood score, fatigue, confusion, anger andvigor. According to some studies, dehydration in the body might even lead to delirium and dementia.

Regular intake of fluids and electrolytes in case of mild dehydration helps in reversing theinduced cognitive deficits.

  1. Gastrointestinal functioning

Fluids in the diet are usually absorbed by the small intestine. Some of it gets absorbed by the colon. If the fluid intake is not adequate, it causes constipation. Constipation is characterized by slow gastrointestinal transit, small hard stools, and difficulty in passing the stool.

Increasing the water intake, ingestion of enough fiber and a clean diet is enough to reverse this lifestyle disease.

5.Kidney Function

The kidneys regulate water balance, blood pressure as well as remove waste from the body. Water regulation is managed through hormonal manipulation, with the goal of maintaining a tight range of plasma osmolality.Increased plasma osmolality leads to the release of arginine vasopressin that reduces urine output and retain water, hence, increasing the urine concentration and vice versa.

The kidneys function efficiently if the water intake is abundant. In cases, where kidneys economize on water, producing a more concentrated urine, there is a greater cost in energy and more wear on their tissues.  This is more likely to occur when the kidneys are under stress, for example, when the diet contains excessive amounts of salt or toxic substances that need to be eliminated.

Drinking enough water helps to protect this vital organ.

6.Cardiac Function

There is a close relationship between blood volume, blood pressure, and heart rate.Blood volume in healthy individuals is fairly regulated by the water intake and the water loss as well.Slight changes in the heart rate or vasoconstriction (narrowing of blood vessels) happen to balance the effect of normal fluctuations in blood volume or blood pressure. Reduction in blood volume is caused either due to accidental blood loss (due to an injury/illness) or voluntary blood loss (due to blood donation, or loss of body water through sweat, as seen with high-intensity exercise).

Water intake relaxes the heart rate and blood pressure in most people irrespective of their native blood pressure. These effects of water intake happen within 15–20 minutes of drinking water and can last for up to 60 minutes. Some studies also say that proper water intake can reduce the severity of headaches, exercise asthma, urinary tract infections and high blood pressure.

Adequate water intake and the resultant drop in core body temperature helps in alleviating such discomforts to some extent.

HYPERHYDRATION (CONSUMING EXCESS WATER) – IS IT REALLY DANGEROUS?

There are studies which say that hyponatremia or very low sodium levels in blood can be caused by hyperhydration. But, all these studieswere conducted on subjects with underlying serious medical conditions. These studies have not been done on healthy individuals. Also, the water intake was not supplemented with a planned increased intake of sodium to maintain the electrolyte balance.

In fact, there are studies that suggest that human kidneys have the capacity to excrete large volumes of diluted urine. They have such flexibility that they may protect the body from hyponatremia in even when water intake is extremely high upto 20L/day. The actual impact can’t be determined in absence of credible research data.

 

HOW MUCH WATER IS SAFE TO CONSUME?

Well, we cannot assign a specific quantity to the daily water intake. It is subjective and varies from person to person. A person with moderate to high activity levels in a day should target to gradually increase their present water intake to 4 to 5 liters per day. Letting thirst be the guide for water intake is also a good strategy. The key is to keep a close tab of body’s signals.

If you are on a calorie deficit diet or you are involved in intense physical activityand you see signs of dizziness, nausea, vomiting, or any discomfort, taking a pinch of pink/black/rock salt with water can help a lot.

So yes, finding one’s own sweet spot is the key here.

 

We now understand the vital role water plays in each and every function of our body. Taking care of hydration should be our utmost priority. Maintenance of hydration paves a path towards overall wellness. So, let’s carry a water bottle everywhere we go,keep track of our intake, consume vegetables and fruits high in water content and help your body reach its optimum health.

KEEP DRINKING!

 

Author credits – Harsh Pal Singh

 

 

References

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908954/

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1323290/

 

https://link.springer.com/article/10.2165/00007256-200737100-00006Q

 

https://doi.org/10.1152/jappl.1996.80.4.1112

 

https://www.ncbi.nlm.nih.gov/pmc/about/copyright/