Water is commonly known to be essential for life, yet a recent study at the University of Sydney found that 82% of the Australian population failed to meet their recommended water intake.
Although the daily amount of water necessary for hydration is currently debated, the Australian National Health and Medical Research Council (NHMRC) has set the recommended intake for Australia and New Zealand at 2.6 litres for adult males, 2.1 litres for adult females and 1.0–1.9 litres for children/adolescents.
Water is necessary for most of the body’s functions such as blood circulation, metabolism, regulation of body temperature and waste removal. Also, considering water makes up a massive 50-80% of body weight (depending on lean body mass), it is essential to be aware of your water consumption. NHMRC advises that as little as 2% dehydration can result in impaired physiological response, mood, cognitive ability and performance.
A 2012 study of university students in London found that those who brought drinks, especially water, along to classes performed up to 10 percent better than those who did not. Another study published in The Journal of Physiology & Behavior found that dehydrated drivers made twice the amount of errors during a two-hour drive compared to hydrated drivers.
Your heart will also thank you for drinking water. The American Journal of Physiology found that drinking five or more glasses (1,185ml) of water per day reduced the risk of fatal coronary heart disease by 41% in women and 54% in men! In this study, the health benefits were limited to water because drinking “fluids other than water” (coffee, tea, juices, soft drinks) actually appeared to increase the risk of fatal coronary heart disease.
Hydration is beneficial in disease prevention as well. The risk of many cancers, including colorectal and urinary tract cancers, has been shown to reduce with proper hydration. Bladder cancer, for example, was shown to decrease by 7% for every 240ml of fluid drunk per day; and was shown to significantly reduce for men who drank at least 1,440ml of fluid per day. Dehydration is also the number one cause of kidney stones.
Without water, our bodies can’t function, so it is always a smart idea to make sure you are properly hydrated. Although there is some debate on using the colour of your urine as an indicator for hydration, general advice suggests the darker your urine, the more likely you are to be dehydrated.
For more information on the benefits and recommendations for drinking water, read Nutrient Reference Values for Water.