Hydration is not just drinking water; it is an intricate physiological process. The balance of fluids, electrolytes, and absorption rate is all controlled. The human body needs to replenish itself with essential minerals such as sodium, potassium, and magnesium to function properly. If these levels are unbalanced, drinking water is not enough to hydrate.
Understanding fluid absorption
This process of fluid absorption is mainly carried out in the small intestine, where water absorption is closely linked with the absorption of sodium. The purpose of this process is to enable the entry of fluids into the bloodstream more efficiently in the presence of electrolytes.
However, the ingestion of large amounts of water in the process of dehydration can lead to the dilution of the level of sodium in the body. Beverages containing electrolytes have been created with the purpose of increasing the efficiency of the process.
Sodium helps in retaining fluids in the bloodstream, thus preventing the loss of fluids through urine. Potassium helps in maintaining the balance inside the cells. A small amount of glucose is present in these drinks to enhance the process of hydration.
Role of foods in hydration
Food helps in the maintenance of hydration levels in the body, both from the perspective of water content and the electrolytes they contain. Fruits and vegetables like watermelons, cucumbers, and citrus fruits have high water content, potassium, and sugars.
Dairy products and whole foods have another aspect to offer in the maintenance of fluid balance in the human body. They have high amounts of sodium, calcium, and proteins, which cause a delay in gastric emptying.
This delay helps in the gradual absorption of fluids into the bloodstream, thereby providing continuous hydration rather than fluctuating levels. The presence of fiber in these foods also helps in the gradual absorption of fluids into the bloodstream, thus providing continuous hydration.
Where food falls short
Despite these advantages, food may not be sufficient in emergencies characterised by excessive fluid loss. This is because sweat contains more sodium than food can replenish within a short time. This method may be impractical and slow.
When one is physically active or exposed to heat or diseases such as diarrhea and vomiting, replenishment of fluids and salts is necessary within a short time. If replenishment is slow, there may be insufficient blood volume in the body, resulting in fatigue, dizziness, and poor concentration.
Practical balance in daily life
Under normal conditions, the body can be adequately hydrated with the help of a balanced diet and adequate water intake. Food can be considered an alternative to electrolyte drinks in normal conditions. Physiological stress conditions require the body to move from the state of maintenance to the state of rapid recovery. Electrolyte drinks help in this condition because they can provide the body with immediate hydration.
Food has been found to contribute significantly to the maintenance of hydration levels in the body by providing hydration along with required electrolytes in a steady state. Though they can contribute to the hydration process in the body, they cannot be compared with the rapid replenishment process provided by electrolyte drinks in the case of acute loss. The best way is the judicious use of water, food, and electrolytes.
(The author is a clinical dietitian and nutritionist at Apollo Spectra Hospital, Bengaluru)
The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.
