Xunzheng

〖Chinese Version-中文版〗

It is amusing as well as amazing to see how things are viewed from utterly different perspectives. One example is the post-lunch sleepiness or after lunch drowsiness.

A TCM scholar plagiarized an article about junk foods. She was asked to explain why a reader wants to sleep after a meal, especially after lunch. She has absolutely no idea about this phenomenon, but that does not prevent her from answering that it is because this person has the “weakness of spleen”. What the hell is “weakness of spleen”?

The spleen is an organ of the immune system and red blood cell maintenance system. The Ancient Chinese had only limited anatomic knowledge about the spleen. All they could see at that time was that the spleen was closely seated to the stomach. Therefore, they hypothesized that the spleen was somehow linked to digestion. Anybody with anything suspected of indigestion or insufficient digestion was termed as “weakness of spleen”. Anatomically the spleen shares blood vessels with the stomach. That’s all. Your spleen has nothing to do with your indigestion!

Not only does the spleen have nothing to do with digestion, but also the post-lunch sleepiness is not related to indigestion. It is somewhat related to digestion all right. When you eat, your digestion system has to be ready to digest the foods. It draws blood to those organs such as the stomach, small intestine (or bowel), large intestine (or bowel) and liver. It shifts blood away from your brain. It might interfere with your brain function a little bit, especially on concentration. However, the main reason for after lunch sleepiness is something inherent in us from our ancient history.

We walked out of Africa. There we had a tropical weather. In the noon there was the scorching sun. The temperature rise to a degree that was intolerably high. Our ancestors chose to stay in the shades and rest during early afternoon. This was evolved into an intrinsic system called circadian cycle—out body is programmed to have highs and lows during a 24-hour period. We inherited this biological clock from our ancestors. The reason we can stay awake at all after lunch is that we can reprogram ourselves and overpower this circadian system.

For a modern life or even people who no longer reside in tropical areas, the post-lunch sleepiness is counterproductive. We are no longer exposed to the sun directly. If we work during the afternoon, we save energy. If we choose to have lunch nap like the Chinese people usually do, we shift work time to the night and we waste energy for lighting. The United States adopts summer time to save energy for the exact same reason. We change our biological clock for work to save the need for lighting. The collective savings are too valuable to be neglected. Fortunately, our biological clock is indeed highly flexible and reprogrammable. But, we still feel the life of our ancestors in us.

The sleepiness or drowsiness does cause inefficiency in our work. Here are several tips to deal with it.

If you are closer to our ancestors than others are, your choice is the apparent: take a nap. If you have sleepless nights and your body is chronically craving for a sleep, your body pushes much harder for you to sleep during this period. Resisting a strong urge to sleep may be counterproductive. You lose both the productivity and the sleep.

Otherwise you want to stay awake and function as normal. You may want to cut down your activity in the night. Chronically depriving yourself of sleep is bad for your health. The time you spend at nigh may simply be stupid stuff that can wait, like, writing this article. Oh, yes, I waited for the day light to write this article.

The food has a large impact on your desire to sleep. If you eat to a full stomach, your body feels a strong signal to sleep. The digestion system secretes a lot of regulatory hormones when active. Some of those directly impact your sleep-wake system while others work indirectly. Melatonin, for example, is the critical sleep regulating hormone that is also produced by the gut. Chinese people should be very familiar with melatonin as the main ingredient in LaoBaiJin (脑白金). pulls blood away from the brain and it likes to shut down completely, even if there is more energy material (sugar) available in the blood. So, it’s best to eat a light lunch. With modern day standard of living, malnutrition stems from overeating. A light lunch is actually healthy.

If you still feel a little bit drowsy, you know that your brain is turning to shutting-down mode. There is a lack of internal stimuli. The patients of attention deficit suffer a chronic lack of internal stimuli. If they let nature take over, they would be in a constant state of sleep. Therefore, their brain figures out that they have to move around. When we are physically active, we send signals to the brain center in charge of the internal stimuli. The center sends out signals to make us alert. It would be suicidal if we move around and brain shuts down. Therefore, attention deficit patients compensate their lack of internal stimuli by hyperactivity. That’s why the condition is called attention deficit hyperactivity (ADHD). When you are drowsy, get up and work around, do stuff that requires physical activity. Once the circadian rhythm passes, you can be as productive as normal.

Drinking coffee can help, but it could interfere with your night sleep. If you stay physically fit overall, you have better capability to manipulate your biological clock. That means regular exercise.

Stay awake and work during the day. That is GREEN!

转载本文请联系原作者获取授权，同时请注明本文来自廖俊林科学网博客。
链接地址：https://blog.sciencenet.cn/blog-460310-388246.html

上一篇：生命之粥（正文）
下一篇：午餐后嗜睡