Hydration and Health

Hydration is integral to health, and water trails only air among the most important substances in maintaining hemodynamics and functional reserve. The human body survives for only a few days without meeting essential water requirements but could sustain itself for several weeks without ingesting macronutrients or micronutrients. Water is involved in critical anatomical and physiological functions, such as in providing mass and structure to the cells, functioning as the medium and reagent for metabolic reactions. Intercellular water binds to proteins, carbohydrates and nucleic acids to maintain their proper function, lubricates adjoining tissues, transports substrate and metabolic waste, and is the primary means for dissipating excess body heat. When a person is dehydrated, the structure of critical cellular biomolecules is adversely affected, reducing their function. All systems are influenced by dehydration, resulting in reduced energy production, neurotoxicity, alteration in the function of concentration of substances within cells, pH changes, and altered enzyme function. Muscle cramping, muscle soreness, constipation, fatigue, and sensitivity to toxic substances all increase during states of dehydration, while mental clarity is reduced. In these cases, water becomes the limiting nutrient for support of functional physiology.


Three simple indicators of hydration status include thirst, body weight, and urine osmolality. Thirst typically lags behind an acute change in hydration, developing after humans incur a 1% to 2% acute reduction in body mass. It is observed that endurance and cognitive performance decline at slightly less than 2% acute loss of body mass. The signal to initiate drinking behavior does not appear to be synchronized to prevent deterioration of function, and therefore thirst is commonly viewed as a less-than-ideal method of tracking hydration. Therefore, thirst should be used in combination with acute change in body weight and urine color to develop fluid intake strategies. Body weight and acute change in body weight following exercise and/or heat exposure are a relatively accurate and reliable measures of hydration status.


Hydration has shown to impact various aspects of human health. Poor hydration status may be associated with compromised oral health, such as dental caries and erosion of dental enamel. Adequate fluid consumption has a positive effect on intestinal and hormonal health. Consumption of water has shown to increase stool weight and volume along with decreasing bowel transit time in some individuals. It has also been associated inversely with certain types of cancers. This is because water consumption results in accelerated transit of potential carcinogens through the intestinal tract and decreased time for exposure and dilution of carcinogens in the water phase (phase 2 detoxification – sulfation and glucuronidation) of the stool. It may also be because of greater intestinal excretion of hormones such as estrogen that are associated with cancer, because weak evidence of a relationship was seen between bowel motility and breast cancer. Enhanced hydration decreases the sympathetic nervous system drive to retain fluids, and increases the parasympathetic activation to excrete fluids, all of which could, in a state of dehydration, facilitate responses leading to hypertension. In individuals who are susceptible to kidney stones, increased water ingestion reduces the risk of subsequent kidney stones, specifically calcium nephrolithiasis with stones composed primarily of calcium oxalate. The mechanism is thought to be a result of the dilution in concentration of materials that would precipitate stones on saturation. Continuous ingestion of water stimulates urine production and contributes to the dilution and excretion.


The WHO has declared that “all people, whatever their stage of development and their social and economic conditions, have the right to have access to an adequate supply of safe drinking water.” Although presence of a public water distribution network is often an indicator of a suitable water supply, it should not be expected that the piped water quality is always adequate for human consumption. Like the fish we eat – which are now significant sources of toxins such as mercury, cocaine, and antidepressants – our water can contain everything from pesticides to substances we add to water as a function of public use (chlorine, fluoride, lead and iron leaking from lead pipes, softening agents), to residues from farming practices, to bacterial or parasitic agents resulting from contamination or overuse. People are also exposed to disinfected drinking, shower, or bathing water containing at least 600 identified disinfectant byproducts.


Citizens of a small town in Colombia had a significant prevalence of autoimmune thyroiditis, which was traced back to the contamination of drinking water with phenolic chemicals. Those chemicals adversely influenced the immune system, resulting in production of anti-thyroid antibodies. When the water supply was purified, the prevalence of autoimmune thyroiditis was significantly reduced in the community.


Closer to home, in April 2014, the city of Flint, Michigan, switched to the Flint River as a temporary drinking water source – without implementing corrosion control – discontinuing the purchase of treated water from the Detroit Water and Sewer Department (DWSD). Ten months later, water samples collected from a Flint residence revealed progressively rising water lead levels – 104, 397, and 707 μg/L – coinciding with increasing water discoloration. An intensive follow-up monitoring event at this home investigated patterns of lead release by flow rate. All water samples contained lead above 15 μg/L and several exceeded hazardous waste levels (>5000 μg/L). After analysis of blood lead data revealed spiking lead in the blood of Flint children in September 2015, a state of emergency was declared and public health interventions (distribution of filters and bottled water) likely averted an even worse exposure event due to rising water lead levels. This incidence will have long-term health consequences in infants as well as in adults, including developmental delays, learning difficulties, mood disorders, miscarriages, joint pains, hypertension, and cognitive decline in adults.


The Safe Drinking Water Act (SDWA) is the federal law that protects public drinking water supplies throughout the nation. Under the SDWA, the Environmental Protection Agency (EPA) sets standards for drinking water quality and, with its partners, implements various technical and financial programs to ensure drinking water safety. Even with the law in place, more action needs to be taken with regards to the water quality. The EPA in January of 2017 initiated a peer review of draft scientific modeling approaches to inform the agency’s evaluation of potential health-based benchmarks for lead in drinking water.


Pure water on this planet has become a diminished resource. These problems have significant health implications, ranging from neurological damage to respiratory problems to gastrointestinal ailments. Access to safe water for drinking, bathing, and normal household use is a very important part of a healthy life — one of which we are most aware when it no longer exists.


One of the smarter options is to recommend patients filter their own water and carry it with them in a stainless-steel bottle. There are many filtering options. A few options would be to use simple carbon filters or a reverse-osmosis filter system, which puts the water through a multistep process to remove the toxins. There is an initial installation cost, but it is cheaper over the long run. Filtering bathing and washing water is also recommended. A whole-house water filter with an additional drinking water filter may be a good option.

Hydration tips:

·          On a sedentary day, try to drink around two liters of water.

·          Start by drinking a glass of fresh water when you get up in the morning.

·          If you are not used to drinking water regularly, try initially replacing just one of your other drinks a day with fresh water, increasing your consumption as the weeks go by.

·          Drink a glass of water before and during each meal.

·          Hot water with fresh mint, lemon balm or a piece of fruit in - like lime, lemon, orange etc. often helps those who want a hot drink.

·          Carry a bottle filled with water with you whenever you leave the house.

·          During exercise, drink at 10 to 15-minute intervals or think of it as a full glass every 30 minutes - drink slowly and drink early, it’s physically easier to do this when you are still feeling fresh.

·          Keep a check on your urine. As a general guide to hydration, it should be plentiful, pale in color and odorless.





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