In December, the cold has suddenly increased. The sun sets earlier and the nights feel longer.

As a result, people tend to sleep longer in winter than in summer. However, many people say they can't wake up refreshed or feel sleepy no matter how much they go to bed.

This time, we once again asked Yuki Hasegawa, a registered dietitian at Argo Medical Salon, why it is difficult to sleep well in the winter, and whether there is anything we can do to improve our nutrition.

Disturbances in hormones and autonomic nerves disrupt sleep in winter

In Chinese medicine, winter is said to be the season for health, and it is said that getting more sleep is better for your body than in summer.

“However, it is also the season when the quality of sleep for many people decreases,” Hasegawa says.

One of the reasons for this is the short daylight hours.

"Melatonin is a well-known hormone that controls sleep. Its secretion is controlled by light, and if you don't get enough sunlight in the morning and during the day, you won't be able to produce enough melatonin at night. In other words, the amount of sunlight increases. During winter, when the sun is short and the sunlight is weak, it is difficult to sleep and the quality of sleep tends to deteriorate.It is in winter that it is necessary to consciously expose yourself to sunlight.

And the disruption of the autonomic nervous system that is unique to winter can also cause poor sleep quality.

``The daily temperature difference is naturally larger in winter than in summer, and in modern society, the heating system creates an even greater difference in temperature.This can lead to disturbances in the autonomic nervous system and reduce the quality of sleep. is"

In order to correct disturbances in the autonomic nervous system, it is important to dress warmly when going out to regulate body temperature, and to get into the habit of light exercise.

Adjust your sleep rhythm with “vitamin B12 + folic acid”

``The quality of your sleep can also be changed by your diet,'' says Hasegawa.

One nutrient that has received particular attention is vitamin B12.

"It is said to have the effect of increasing photosensitivity, promoting sleep, and regulating the body's internal clock.It is found in large amounts in animal proteins such as beef and seafood, and・Since metabolism differs from person to person, many people may not be getting enough of it.Actually, in my case, when I supplemented with supplements, the quality of my sleep improved significantly.

Also, it is important to take folic acid along with vitamin B12.

``Although it may be thought of as a nutrient necessary for pregnant women, it has the characteristic that it works together with vitamin B12.It prevents anemia and improves blood flow, so it is useful for people who are sensitive to cold and have difficulty sleeping due to cold hands and feet. However, for some people, taking vitamin B12 and folic acid at night may activate the nerves too much and cause mid-morning awakenings.We recommend taking them in the morning.

Deficiency of vitamin D impairs sleep quality

Another nutrient that you should pay attention to is vitamin D.

"When you hear vitamin D, you probably think of it as a nutrient that is good for bone health, but we have discovered that it has a variety of other effects as well. One of these is its relationship to the quality and quantity of sleep." said Mr. Hasegawa.

I mentioned earlier that the quality of your sleep tends to deteriorate if you don't get enough sunlight, but vitamin D is a nutrient that is called the "sunshine vitamin" and is produced by exposure to sunlight.
It also plays a role in the synthesis of serotonin, which is involved in the production of melatonin, which induces sleepiness at night, and therefore affects sleep.

``In winter, when there is less sunlight, it is difficult to produce vitamin D, and you tend to be deficient in vitamin D.As a result, the amount of melatonin produced also decreases.In terms of food, we eat dried shiitake mushrooms, wood ear mushrooms, dried whitebait, and sardines. It is found in foods that have been exposed to the sun, such as whole dried fish, as well as salmon and salmon roe.Especially during the winter, you should be conscious of eating foods that contain vitamin D.

However, it is said that many Japanese people are deficient in vitamin D. It is better to supplement with supplements even just during the winter.

What foods should you avoid for a good night's sleep?

``Some foods can improve your sleep quality, and vice versa.Caffeine is a particular example.Coffee, black tea, green tea, and even chocolate can lead to wakefulness, so avoid them before bedtime as they can lower your sleep quality.'' By the way, if I drink coffee after noon, I won't be able to sleep much,'' says Hasegawa.

If you're going to consume something with caffeine, like coffee, the best time is in the morning. If you really want to drink coffee in the afternoon, go for decaf.
We believe that choosing what and when to eat black tea, green tea, non-caffeinated tea, and herbal tea according to your physical condition and constitution will lead to good sleep and rest.

``Also, eating lots of vegetables and fruits that contain a lot of water and potassium before going to bed can cause you to wake up to use the bathroom in the middle of the night.However, mineral balance is very important for quality sleep, so After all, a well-balanced diet is very important.”

Alcohol is something I'm concerned about as we approach the New Year holidays.

``Alcohol is good for falling asleep, but it reduces the quality of your sleep.It also has a diuretic effect, so you may wake up suddenly in the middle of the night and want to go to the bathroom.However, There are many opportunities to drink alcohol during the year-end and New Year holidays, so I want to be able to handle it well.Also, during the party season, I tend to eat too much.It puts a strain on my stomach and intestines, which lowers the quality of my sleep.Especially animal protein. Eating fats and fats before going to sleep is not good for digestion and absorption, and can lead to fatigue after waking up, so eat in moderation.

summary

I learned that it is important to take vitamin B12, folic acid, and vitamin D for good quality sleep. As we approach the busy year-end and New Year holidays, we want to rest our bodies with good quality sleep. Stay healthy with vitamin supplements on your side.




Yuki Hasegawa
Argo Medical Salon Registered Dietitian. At Argo Medical, we work with each individual to create custom-made medical care tailored to each person, including those who are worried about their physical condition, and those who do not have any health problems but would like to improve their performance as an investment in themselves. At the salon, she provides detailed guidance on nutrition.

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