Sometimes I don’t know whether to laugh or cry when I read stuff on the internet. Take, for example, the article on news.com.au today about the long-held notion that drinking eight glasses of water a day is good for you.
The article centered around comments made by a lecturer at La Trobe University, Spero Tsindos, that you didn’t need to drink eight glasses of water a day to maintain your fluid balance, and that continuing to make such a statement to the public was just perpetuating a myth.
Stripped of its context, such comments make Tsindos sound like a douche bag, though what offended me more was the layer upon layer of arrogance and ignorance that followed in the comments section. Some of the comments were from people that were genuinely confused by the disparity between what the article appeared to say and what their personal trainer keeps telling them. Others were just plain stupid, or perpetuated hysterical mistruths from people that probably should have known better, which just made it all the worse for the people suffering from genuine confusion.
So while it may not be ever be appreciated by the readers of news.com.au, if I don’t try to rectify the myriad of mistruths ensuing from this article, I’ll spontaneously combust.
First of all, lets add some context to the comments made by Mr Tsindos. The poor guy was just engaging in a robust intellectual debate with other public health academics, in a peer-reviewed forum, considered the most appropriate vehicle for such debate. He was not making a statement to the press, or writing something for the lay public. His letter was probably part of a whole series of debate for and against the idea that eight glasses of water a day is mandatory for good health. Intellectual debate in journals takes a lot longer than posting to facebook, but unfortunately the general public has an attention span shorter than the average goldfish and can only process one paragraph at a time, so the notion of intellectual debate is lost on them.
And for the record, Mr Tsindos is correct in that whatever we put in our mouths contributes to our fluid balance since most of the food we eat contains a lot of water. So do all fluids, be they water, milk, juices or soft drinks. Even coffee adds to your fluid balance, despite the caffeine, but we will get to that later. He was talking about our fluid balance not our overall health. Unfortunately, again due to our collective attention deficit disorder and our affinity for jumping to conclusions, that was lost on most people.
The comments ranged from the reasonable, “Isn’t coffee a diuretic, so wouldn’t drinking lots of coffee dehydrate you” to the ignorant pseudo-experts, “Everyone should be taught to interpret the colour of their urine properly to see if they are adequately hydrated.” And from the plain hysterical, “Coffee is pure acid. Coffee taxes the liver”, to the ridiculously hysterical, “It’s all a conspiracy from juice/coffee companies to deceive you. Just like evil doctors that push vaccinations full of mercury, that all cause autism.”
First of all, caffeine is a weak diuretic. Diuretics are drugs that make your kidneys produce more urine. People who are not used to caffeine will get a diuresis from coffee. But unless you drink nothing but espressos, there is usually more fluid in the coffee than the small increase in urine output from the caffeine. And like all drugs, your body develops a tolerance for the diuretic effect of caffeine after a while, so habitual coffee drinkers will get a reduced effect, increasing the fluid contribution from coffee. You will not dehydrate if you drink nothing but coffee.
And the suggestion that coffee is taxing to your liver and leads to health problems is a myth still held dear by alternative practitioners and overzealous nutritionists. Broad population studies that follow hundreds of thousands of coffee drinkers for decades have shown that coffee drinkers live longer than non-coffee drinkers, especially chronic habitual coffee drinkers who drink over four cups a day.
Back to the notion that you need to drink 8 glasses of water to be healthy. Broad generalisations are like one-size-fits-all clothing … they usually don’t fit anyone properly. The same goes for the idea about the number of glasses of water that you should drink. You drink the water that you need to drink. How do you know how much? The human body has been pre-equipped with the ability to determine exactly how much water we need in a day, and it has nothing to do with eight glasses or the colour of our urine. It is thirst. If you are thirsty, drink some water. If you are not thirsty, don’t drink water. It’s not that complicated, is it?
The point with the eight-glasses-of-water dictum is that water is beneficial and we don’t drink enough of it. On this point, I agree with Tsindos, the eight glasses rule should be discarded. Rather, all we need to say is, “drink more water”. When you are thirsty, choose to drink water instead of soft drinks or fruit juice. It’s that simple.
When I have more time I will write a blog about all the virtues of water, because if a drug-company could, they would patent it, such is the overall health benefits of water. But for now, just remember to drink more water in line with your thirst.
Oh, and lets cut Mr Tsindos some slack.