Table of Contents
It’s fat-free, has zero calories, is always ‘on tap’ (literally) and is essential to life. We’re told to drink more of it, but is it really so good for our health?
Water makes up 60% of our body weight and is vital for essential functions such as maintaining blood pressure, eliminating waste products and preventing delicate mucous membranes in our nose, mouth and lungs from drying out. But apart from the essential stuff, what else can it do for us?
Research found those who drank five glasses of water a day were less likely to have potentially fatal heart disease, compared with those drinking two glasses.
Water absorbed by fibre passing through the digestive system, bulks out stools making them softer and easier to pass. (Many laxatives work on exactly this principle by drawing water into the stool). So not drinking enough water is likely to cause constipation.
A study in men found those drinking 10.5 glasses of water a day were 24% less likely to develop bladder cancer, while another showed the risk of certain types of bladder cancer to be halved in men who drank 11 glasses a day. Large quantities of water may be quickly washing cancer-causing agents out of the body, so they cannot accumulate.
Women have also been shown to be at lower risk of cancers affecting the bladder and kidneys the more fluid (of all types) is consumed - water straight from the tap having the strongest effect.
Other research showed a greater reduction in men: 92.4% for rectal cancer and 42% for colorectal cancer. Water increases the rate at which stools pass though the bowel, reducing contact time between cancer-causing agents and the bowel lining.
The risk of breast cancer is also affected by drinking water - a study showed risk was reduced by 79% in post-menopausal women and by 33% in premenopausal. This demonstrates the importance of water to normal functioning –at low levels cells are less able to filter out toxins.
Avoid diabetes by drinking water
Not drinking enough fluid has also been found to increase risk of developing high blood sugar, which can lead to diabetes. In a study, those drinking less than half a litre a day were more likely to develop high blood sugar than those drinking a litre or more. The link here is a hormone (vasopressin or ADH) secreted by the brain when fluid levels are low. It leads the kidneys to retain water, but causes the liver to release glucose into the blood. So the more vasopressin released due to dehydration, the higher blood sugar levels become.