Water is the one nutrient in our life that if eliminated, will be fatal in days. that being said, I have recently read a research article the benefits of water but I found most interesting was the results that dehydration plays on our bodies. I have written down the key parts that I found most important and the effects it has on our bodies.
The role of water in athletes and military is very important to reach their full potential. During an athletic event, it is common to lose 6-10% of body weight in sweat alone which can lead to dehydration very quickly if that fluid is not replenished during and after the activity. With that being said, decrease in physical performance has been observed in very mild state of dehydration, with as little at 2% loss. The decrease in performance pertains to fatigue, reduced endurance, decreased motivation, and increased perceived effort. Simple rehydration can change those effects easily. Children are at higher risk for dehydration during physical activity due to their decreased recognition of thirst.
Moderate dehydration can cause mood changes and cognitive functions, it is more of a concern for those that are very young or old, in hot climates, and engaging is strenuous exercise. Side effects can be decreases in concentration, alertness, short-term memory, as well as physical functions. Certain studies have shown that heat-stress dehydration can play a larger role in decrease cognitive function than just lack of fluid intake throughout a 24 hour time period. Again, simple reintroduction of water will help alleviate all the side effects.
Dehydration has been shown as one of the predisposing factors of confusion in long-term care residents. The older population have been shown to have lower thirst than younger population and the hydration status in elderly population gets complicated by disease states, incontinence, decrease kidney function, decreased mobility, and medication usage.
Constipation can be caused by low fiber diet, poor diet, illness, and/or medications. Increasing fluid is one of the first things told to a person struggling with constipation however there are studies out there showing that fluid increase only helps with constipation when the person is under-hydrated. In the study, children that suffered from chronic constipation, increasing water intake by 50% did not improve the affects of constipation.
It is a common known thing that when suffering from a headache, you are told to increase fluids to help improve the pain. With that being said, it is a topic that is not explored in depth in the medical community. In an observational study, decrease water intake can impair cognition, increase irritability, and can be a trigger for a migraine. Although water can help relieve those symptoms, the utility of water preventing headaches is not as well documented.
One common myth has to do with our skin health and water intake. Many believe that increasing fluid will give them a more moisturized look and that it will also help with acne or other skin conditions however there is no evidence that increasing fluid will help with any of those. The skin does play a role in maintaining body water levels and preventing water loss into the environment.
Our skin contains about 30% water which contributes to plumpness, elasticity, and resiliency. Water increase, particularly in people with low initial intake can improve skin thickness and density as measured by sonogram, which can offset water loss through skin and improve skin hydration. However good skin hydration will not offset or prevent wrinkles or other signs aging that are related to genetics, sun damage, and environmental damage.
Popkin, B.M., D’Anci, K.E., Rosenberg, I.H. (2010). Water, Hydration and Health. Nutr Rev. 68(8),439–458. doi: 10.1111/j.1753-4887.2010.00304.x