We’re smack dab in the middle of summer, and I bet a lot of you are going to enjoy a cool refreshing drink of water. It feels great, and I’ve always assumed it felt great because I was thirsty and needed the hydration. According to science: WRONG!
Apparently, there’s no connection between the body’s fluid monitoring systems and the pleasure centers in the brain that light up when we drink a cold beverage.
Have you ever been in the hospital with an IV? I have. And if you have you know that you didn’t get any pleasure from it, even though the IV was keeping you nice and hydrated.
Some researchers looked at different methods of hydration in mice, and found the same thing. When the mice drank cool water, their brains released a bunch of dopamine, a feel good hormone. But when water was sent directly to their stomachs, no dopamine. Each method resulted in hydration and thirst quenching, but only the gulping of the water produced a thrill.
As you get dehydrated, you have less water in your blood. Your brain detects this and sends a thirst message to you. You gulp down a cold drink and feel better immediately, but of course it will be several minutes before any of that water actually gets into your bloodstream. So something else is afoot.
The answer may well be in the gulping motion, not the actual water. There is a set of cells in a part of your brain called the median preoptic nucleus. When you drink, these cells tell other cells in your thirst detection system that drinking is happening. So, I guess, that immediate feeling of pleasure when you drink some cold water is not the hydration, it’s the signal that hydration is coming soon.
The study with the mice was published in the journal Neuron.
The gulping study was published in the journal Nature.