Milk sleep may only be a psychological effect
Drink a cup of hot milk before bed, your body will face these problems
Intern reporter Dai Xiaopei
In the recently popular online drama "Secret Corner", mom Zhou Chunhong forced his son Zhu Chaoyang to drink hot milk every night, which impressed many netizens. In reality, many people also have the habit of drinking milk before going to bed, because we often hear a saying: drinking milk before going to bed helps sleep.
Is this really the case? If yes, what is the principle of milk-assisted sleep? If not, where does the idea of milk help sleep come from?
L-tryptophan in milk promotes the secretion of hypnotic substances
"Milk contains L-tryptophan, this substance can promote the body to secrete serotonin and melatonin." Li Yun, a professor at Shantou University School of Medicine and director of the Shantou University Sleep Medicine Center, told the Science and Technology Daily reporter that serotonin and melatonin Melatonin can directly or indirectly promote sleep.
Serotonin, also known as serotonin, was first discovered in serum and is an inhibitory neurotransmitter, mainly concentrated in the suture nucleus of the brain stem. After research, serotonin must pass through the corresponding receptors to play a role, so far people have found 7 serotonin subfamilies, 14 subtypes, serotonin by activating different receptors to play different physiological roles.
Someone once damaged the head and tail of the midslit nuclei of rats, and they all found that the rats had reduced sleep. "This shows that serotonin is good for sleep, but the specific mechanism is not yet clear." Li Yun said.
Other studies have found that serotonin has the effect of maintaining awakening. "Sleeping requires sleep pressure, that is, the feeling of wanting to sleep. The longer you are awake, the stronger the feeling of wanting to sleep. On the contrary, if you have been in a drowsy state, it is more difficult to fall asleep." Li Yun said, 5 -Serotonin is beneficial for maintaining awakeness, and it increases the stress of sleep to a certain extent.
In addition, serotonin is also used to treat mental diseases, because insufficient serotonin secretion can easily lead to depression, anxiety and other emotions. "In terms of psychological factors, depression and anxiety affect sleep quality." Li Yun said.
Melatonin has a direct effect on sleep. "It is dark or the light is dimmed, the light received by the retina is reduced, and the secretion of melatonin will increase accordingly, which promotes sleep. According to the biological rhythm, the secretion of melatonin will increase after 10 o'clock in the evening, increasing sleepiness." Li Yun said that at night watching mobile phones, computers, etc., will be exposed to more blue light, the brain mistakenly believes that it is still daytime, the secretion of melatonin will be reduced, which will have an adverse effect on sleep.
A previous study by Sanyu University in Seoul, South Korea, showed that milk squeezed at night contains more L-tryptophan and melatonin. These chemicals can help people reduce anxiety.
The intake is negligible and the effect is minimal
"In theory, L-tryptophan in milk can produce substances that promote sleep. Drinking milk helps sleep. But from a practical perspective, L-tryptophan obtained from a glass of milk can basically be ignored. It doesn’t count, so it doesn’t produce enough serotonin and melatonin to make us sleep better.” Li Yun said.
Experts say that if you eat a balanced diet, there will generally be no L-tryptophan deficiency, and there is no need to supplement L-tryptophan by drinking milk.
So why does the expression "drinking milk before bed help sleep"?
This is because drinking milk is prone to fullness, and it is easier to fall asleep after eating. "This is because after eating, blood flows back to the stomach, resulting in insufficient blood supply to the brain and easy to fall asleep." Li Yun emphasized that eating too much before bed is not conducive to sleep.
In addition, another reason is that drinking milk before going to bed is usually drinking hot milk, which will make people feel relaxed and comfortable, thus alleviating some of the anxiety. Some people think that drinking milk before going to bed helps sleep may be a psychological effect.
"It should be noted that drinking too much milk before going to bed is just like drinking too much water or eating too much watermelon at night, increasing the probability of getting up to the toilet in the middle of the night, thus affecting deep sleep." Li Yun said.
In addition, whole milk has a high fat content, and drinking it before bed may cause weight gain. "Drinking about 150 ml of skimmed or semi-skimmed milk before going to bed will not affect your weight too much." Li Yun said that it is best to drink milk about an hour before going to bed.
One point that cannot be ignored is that some people are not suitable for drinking milk. "Not only do not drink before going to bed, but also drink less." Li Yun said. For example, people who are prone to bloating, many people drink milk and their stomachs will swell, affecting sleep; people who are lactose intolerant drink milk easily diarrhea; people who have had abdominal surgery are not suitable for drinking milk; drinking milk will promote gastric acid secretion, so there are People with gastrointestinal ulcers, cholecystitis and other gastrointestinal diseases should avoid drinking milk. In addition, patients with milk allergies and urinary stones should not drink milk.
"To sum up, in theory, L-tryptophan in milk helps to produce hypnotic substances, but the intake of L-tryptophan from milk is very limited. Moreover, some people are not suitable for drinking milk." Li Yun said .