We’re told to drink 6-8 glasses of water each day to keep our body functioning properly. So, does this mean our body will reap twice the benefits from drinking double this amount of water?
Nigella Lawson recently described herself as an aquaholic given the copious volumes of water she drinks each day – including a whopping 3 litres before bed! Just like Nigella, most of us are aware that drinking too little water is no good for our body but few of us realise the dangers of drinking too much water.
There’s no doubting that maintaining our body’s water content is essential. We use and lose water each day in basic processes like metabolism and sweating. However, we only need to refill as much as we lose. The old adage “the more the better” certainly doesn’t hold true for drinking.
We wouldn’t think of filling a glass with water or a car with petrol beyond what is needed. We don’t continue filling up until we find ourselves standing in a pool of liquid. Anyone would think you were mad. Yet this is sort of what we’re doing with incessant drinking. The only difference is the excess fluid doesn’t simply overflow. Instead, drinking too much water dilutes the fluid in our body
You see, the fluid in our body is not just water. It’s water along with a range of different dissolved substances, such as electrolytes. One of those substances is sodium, a type of electrolyte that we gain through our diet and lose through sweating. The concentration of sodium in our body fluid is also a useful marker of our hydration level. If we’re dehydrated, for example, the relatively low water content will mean the concentration of sodium is too high. This situation is not ideal and hence, we are told to drink adequate water each day.
However, the opposite is no better. If we drink too much water, we cause a state of overhydration and reduce the concentration of sodium to a level that’s too low. This condition is known as hyponatraemia, which simply means low sodium. It occurs when we basically dilute the sodium in our body fluid by drinking too much water. It’s like making up a glass of cordial according to the instructions with 10% cordial and 90% water and then adding more and more water until the mixture is 2% cordial and 98% water. The consequence is more serious than a glass of tasteless cordial.
Hyponatraemia or “water intoxication” affects the function of our central nervous system – our brain and spinal cord – in a way similar to excess alcohol. Worryingly, the early symptoms of too little and too much water, such as headache and confusion, are similar. So in some cases of overhydration, the symptoms have been misinterpreted and the person is encouraged to drink more water. If left untreated or mistreated with additional water, symptoms can progress to hallucinations, convulsions, coma and death.
In recent years, there have been deaths from all walks of life as a result of water intoxication, ranging from a marathon runner or Army trainee who have lost sodium in their sweat whilst simultaneously rehydrating with water to a contestant in a water-drinking competition who guzzled too much water to win a prize to a singer who drank copious volumes of water to keep their vocal cords moist or just your average Joe.
For most of us who drink water in moderation, there is no cause for alarm. But for those of us who drink significantly more than the recommended 6 – 8 glasses each day under the assumption water is the last thing that can do harm, beware. It goes to show, just about anything in excess has the potential to be harmful.