What Happens To Your Body When You Drink Old Water?
Water doesn't go bad for years. It's water. Right? We might all see the "best before 2050" labels on our plastic bottles, but nobody is actually paying attention to them because, well, we don't have to. But, what actually constitutes "old" water? Is it water that's been left stewing for days, weeks, or months? Or does overnight water pose a potential risk to us, too? We know that we have to drink water every day, but does the age of the water really mean anything?
Most people leave a glass of water next to their bed to re-hydrate first thing in the morning, but did you know even that could be a bit sketchy, scientifically speaking? We're all trying to do our best for the environment by re-using and recycling but, when it comes to water, fresh is actually always best.
Old water contains bacteria, but it's generally yours
Reader's Digest notes that water left overnight in an open container isn't exactly sanitary due to the amount of dust, debris, or even insects that land in it, which can leave a gross scum on the surface. Even closed containers aren't completely safe, because anything that's on our skin — sweat, dust, skin cells, or any kind of discharge like spit or mucus — can end up in the bottle once we take that first sip.
"If it's allowed to incubate for hours, that could potentially contaminate the water, and make you ill by reintroducing that bacteria," warns Marc Leavey, M.D., who suggests consuming the bottle in one sitting and then throwing it away. However, since it's your bacteria, you likely won't get sick from it. But sharing bottles with other people is not advised, for obvious reasons.
If you leave a bottle of water in direct sunlight, like in your car, for example, the heat could cause bacteria to grow. Likewise, certain plastic bottles contain chemicals like BPA, which can leach into the water if exposed to sunlight. Certain research links BPA to certain health problems, such as increased blood pressure, so it's a good idea to avoid any extra exposure.
It's highly unlikely old water will make you ill
Microbiologist Charles Gerba, Ph.D. also warned, in a conversation with SELF, that bacteria on our fingers can possibly contaminate water too (you're always safer with a screw cap, FYI). However, even smelly bottles are likely just encrusted with saliva, mouth bacteria, or even some mildew or mold, and there's likely nothing to worry about.
If you're really freaking out about the bacteria in old water, or even on the plastic bottle itself, Dr. Leavey suggests, "Avoid putting your mouth to the bottle. Just pour it into a cup or pour it directly into your mouth." Start paying attention to those expiration dates, too, because they really do matter.