5 Myths About Water Drinking
Why do you need to drink water?
Water is an essential nutrient that enables biochemical reactions, excretion of waste from your body by the urine, and sweating, among other. You constantly lose water from the body, so you need to replace it regularly.
There is one main thing you need to know: you need to drink only the amount of water you have lost from your body, not more. If you have lost two liters of water, you need to drink two liters and if you have lost five liters you need to drink five liters.
You can know you drink enough when your urine is clear or pale yellow and you are maintaining your usual body weight. If you miss, for example, three liters of water, you will lose three kilograms (~6 pounds) of body weight.
Apart for prevention of kidney stones in individuals with kidney stones, drinking more water than you need to be well hydrated has no known health benefits.
Very little or no urine
1-3% loss of body weight
4-6% loss of b.w.
>6% loss of b.w.
Myth 1. "It is healthy to drink a lot of water."
We do not need to drink a lot of water to be healthy, we just need to drink it enough. As long as we maintain our usual body weight and we excrete clear urine at least three to five times per day, we are probably well hydrated.
We quickly excrete any excessive amount of water by urination. If we urinate more than eight times a day, we probably drink more than we need.
The only known health risk from chronic low water intake is increased frequency of kidney stones in individuals with recurrent stones. It has been believed for a long time that drinking a lot of water can prevent kidney stones, which may be the case in people who already have kidney stones, but less likely in healthy people.
It is a widespread hype that drinking a lot of water helps to remove toxins from our bodies, but there seems to be no scientific proof that this actually happens. They are our livers and kidneys that can remove toxins when we drink enough, not necessary a lot.
Myth 2. "Dehydration is the main cause of hangover."
Hangover includes headache and nausea after excessive alcohol drinking. It is a popular belief that hangover is caused by dehydration caused by alcohol, but this does not seem to be scientifically proven.
People often say that drinking water helps them to get over hangover. This may be true, but it does not automatically mean that water helps because it corrects dehydration. Water can simply flush the excessive gastric juice from the stomach further into the intestine, which can relieve nausea. Many people experience immediate hangover relief after vomiting, which further speaks for stomach irritation rather than dehydration as a cause of hangover nausea.
Dehydration symptoms can, like hangover, include nausea and headache, but when we are dehydrated due to insufficient water drinking, we usually do not say that we feel hungover. So, again, dehydration may not be the main cause of unease in hangover.
Hangover may be caused by ethanol, colorants and other ingredients of alcoholic beverages and our reaction to them.
Myth 3. "It is dangerous to drink distilled water."
Drinking distilled water in usual amounts is not dangerous until we are healthy and eat regularly. The idea that distilled water is harmful originates from the fact that it contains no minerals, so it could leach minerals from our bodies. This is misleading, because we get most minerals, such as calcium, phosphorus, sodium, potassium, magnesium and zinc, from foods, not from water. Also, at the point when distilled water enters the blood, it is no more distilled, because, before absorption, it mixes up with food and hydrochloric acid in the stomach and intestinal juices, which all contain minerals.
On the other hand, distilled water is less optimal for health than clean tap or mineral water because it contains no minerals and has no taste and hence does not stimulate drinking; it is also excreted from our bodies faster than usual tap or mineral water.
Deionized water and water purified by reverse osmosis are very similar to distilled water: they are not harmful, but are less optimal than tap or bottle water with some minerals.
Myth 4. "Drinking one liter of water per hour can kill you."
Drinking large amounts of water in a short time can actually be dangerous, but drinking one liter of water in an hour should not be harmful for a healthy adult. According to the Current U.S. Military Fluid Replacement Guidelines, adult men should not drink more than 1.4 liters of water per hour for several hours in a row.
Drinking excessive amounts of water can result in a drop of blood sodium levels (hyponatremia), which can result in brain swelling and, eventually, in death.
In 2008, in the UK, one 40-years old woman who was on a "water diet" with very little food and hence very low sodium intake, one day, after about one week into the diet, drank about four liters of water in about two hours; she collapsed thereafter and died in the hospital the next day.
Healthy breastfed or formula fed infants, even those living in hot climates, should get no additional water. Giving as little as one cup (237 mL) of plain water to an infant younger than six months can result in a dangerously low blood sodium levels.
Myth 5. "Drinking hard water can result in the hardening of the arteries and kidney stones."
There seems to be no reason to believe that hard water is harmful for health. Hard water contains a lot of calcium and/or magnesium. High magnesium intake is associated with a decreased risk of hardening of the coronary heart arteries. It is not known if drinking hard water helps to prevent artery hardening, but there seems to be no firm evidence that it increases it.
Drinking hard water also does not increase the risk of kidney stones; it can even decrease it. The most common kidney stones are composed of calcium oxalate. One of the risk factors for calcium oxalate stones is high consumption of foods high in oxalate, such as black tea, dark beer, spinach and chocolate. High intake of calcium from food or water hampers the absorption of oxalate in the intestine and consequently its excretion into the urine and may hence decrease the risk of calcium-oxalate kidney stones.
What about mineral water?
Mineral water is often considered especially healthy, but you should expect it will prevent or cure some disease.
Minerals most commonly found in mineral water are calcium, magnesium and sodium but rarely in amounts that would be especially beneficial or harmful for health. Calcium can be found even in plain tap water and we usually get more than enough sodium from foods.
The main benefit of mineral water can be its pleasant taste, which encourages drinking.
Water Drinking Habits
How much water (all beverages included) do you drink per day?
Key Points to Remember
- You need to drink only s much water as you lose: about 2 L/day when you do not sweat much and as much as 5 L/day or more when you are active or the weather is hot.
- Main symptoms of dehydration are dry mouth, dark urine and sudden weight loss. Thirst is common but unreliable symptom of dehydration.
- Hangover is caused by alcohol and added substances (congeners). Dehydration does not cause hangover but can make it worse.
- Drinking as little as 2 liters of water per hour for several hours in a row while consuming no sodium may result in water intoxication with brain swelling and death.