Eating chocolate makes the pain unclear, its mechanism revealed

Even though there are disgusting things, there are many people who feel better when you eat delicious things, but when you actually eat chocolate or drink water, the reaction to thermal stimulation gets dull, that is, pain It was confirmed in an experiment using rats that it became difficult to feel.

This natural "pain relief" effect may be an important function for survival that wildlife does not distract from food during feeding, but for modern people who can easily obtain abundant food it becomes obese It may be a connecting factor.

Details are as below.Comfort Food: Chocolate, Water Reduce Pain Response To Heat

The Journal of NeuroscienceIt was announced in the magazineUniversity of ChicagoStudies by Professors Peggy Mason and Associate Professor Hayley Foo of the Department of Neurobiology of the University for the first time showed that a strong analgesic effect when an animal ingests food or liquid is caused by eating things when there is no appetite It was.

"This is a very powerful action, but it has nothing to do with hunger and appetite," Mason said. "If there is a large amount of food easily reachable in front of you, basically it will not be a reason to stop eating almost anything."

In the experiment, rats were given a small piece of chocolate, water or sugar water was injected directly into the mouth, and the rat switched the lamp under the cage as soon as chocolate and liquid were only pumped. Thermal stimulation of this lamp causes the rat to separate the front leg from the floor. As a result, during eating and drinking, it seems that the time from the application of thermal stimulation to the lifting of the leg was quite long, compared with the experimental time when rats were awake, but not during the diet .

Also, unexpectedly it was confirmed that even when you are drinking water just as when eating chocolate it is confirmed that the reaction to thermal stimulus slows down, so that only sugar containing substances have analgesic effect so far It is a result of overturning our viewpoint.

"This often shows that (analgesic effect) has nothing to do with calories, there is no calorie in the water,saccharinAlthough it does not contain sugar, it has the same effect as a chocolate chip. It is surprising, "Professor Mason says.

Next, to ratsquinine(A bitter liquid that causes a reaction such as "wet" at the time of eating bad foods) to rats, and carried out an experiment to light the lamp just like when chocolate and water, I did not eat anything It was suggested that it responded to thermal stimulation at the same speed as it was, and it is suggested that unpleasant food and drinks can not obtain the effect of dampening pain.

It turned out that the state of rats before giving chocolate and liquid also greatly influences whether or not analgesic action can be obtained by eating and drinking. In the rats that were made into a condition like foods by medication administration, there was no delay in response to thermal stimulation while eating chocolate, but it was confirmed that pain was hard to feel while drinking water And this suggests that the brain considers that drinking water is beneficial when sickness is bad.

Professor Mason and colleagues showed a large seam line of rat brain stem (Daiseho,Nucleus raphe magnus: NRM) by selectively inactivating the part known as a pain-damping function during sleep and during urination, we succeeded in removing the analgesic effect of drinking water. The brainstem is the part responsible for subconscious reactions such as sweating and breathing during exercise.

"NRM is a part of its brainstem basically, human beings are the mercy of the brain stem, NRM is a part of the brainstem.If you are running, you like sweating regardless of liking, regardless of liking I will command you to complete this, "Professor Mason said. "In the wild, rats and other animals do not want to get in the way of meals for valuable opportunities that have been found in foods and drinks, so NRM is activated during eating and drinking, and until the meal is completed (such as pain) If this natural analgesic action works while eating or drinking a pleasant thing and encounters an unpleasant taste that is highly likely to be poisonous or harmful, it works It is self-evident that there is no such thing. "

Brandeis UniversityDon Katz, an associate professor of psychology and neuroscience who studies taste at the same time, said that Professor Mason and Associate Professor Foo would integrate the two systems normally studied separately, usually the taste system and the pain sensation system I am talking. "In other words, the purpose of the taste system is to give animals instructions to help decide which stimulus to ignore and which stimulus to watch out," Katz said. "The whole area is working for the purpose of allowing animals to keep eating"

This reaction that it becomes hard to feel pain during eating and drinking is also found in humans (In the past research by other researchers, the same effect was seen in infants given sugar water when receiving immunization) Professor Mason thinks that it will have a harmful effect in a modern society where large amounts of easy and easy-to-eat foods are comfortable and thick on the tongue. Even though I know it is bad for a person, it is probably because the brainstem is activated like that when I opened the bag because I would like to eat potato chips one bag at a stretch.

"The obesity has advanced considerably in the past 100 to 150 years.It is not less hungry than in the past.The amount to eat increased because it became easy to obtain food, hand We are biologically destined to eat all the food that goes into it, "Professor Mason said. However, it is said that the analgesic effect by eating and drink certified this time can be effectively used. "For example, a doctor may give a candy to make a child calm during medical treatment, but since it was found that sugar is not necessary to obtain analgesic action by eating and drinking, it is now time to replace candy It would be nice to give a glass of water to the cup. "