Having a decent quality sleep depends on a fair number of things, one being nutrition. Nutritionist He Hanyi, founder of the Taiwan Integrated Functional Medicine Education Center, explained during an interview on NTDTV’s “Health 1+1” program how to promote melatonin secretion through daily diet and improve sleep quality.

Melatonin, also known as the “sleep hormone,” plays a significant role in regulating the sleep-wake cycle. The amount of melatonin secreted is related to environmental light intensity. When there is less light at night, the pineal gland in the brain secretes melatonin to help us fall asleep. When the light brightens in the morning, melatonin secretion decreases, and we wake up on our own.

Ways to Increase Melatonin

The following are ways to boost melatonin production to ensure a good night’s sleep.

1. Sunshine

Exposure to the sun during the day not only promotes the synthesis of vitamin D but also helps the body synthesize melatonin. When the eyes see sunlight, they transmit this message to the brain to regulate the biological clock (circadian rhythm). During the day, the brain synthesizes serotonin and converts it into melatonin when the light is gone.

Nutritionist He added that both the intensity and time of sunlight exposure are particularly important. Indoor light or sunlight through the window lacks the intensity, so it is best to bask directly under outdoor sunshine. In addition, one should avoid long naps during the day (longer than 30 minutes) and try to take them before 2 p.m.

2. Nutrition

In the interview, He pointed out that it is best to eat at the same time every day and stick to consistent portion sizes to support the circadian rhythm. This will help keep the body more energetic during the day, making it feel tired naturally at night so it is easier to fall asleep.

The following nutrients play a role in melatonin synthesis:

• Tryptophan: This amino acid is the raw material for serotonin synthesis and melatonin conversion. Tryptophan is mainly found in protein-rich foods, such as turkey meat, pork, fish, pumpkin seeds, milk, soybeans, and grains.
• B Vitamins: Folic acid (vitamin B9) and vitamins B6 and B12 play a role in the synthesis of both serotonin and melatonin. Dark green vegetables, liver, seaweed, shiitake mushrooms, and other foods are rich in folic acid. Studies have found that people with lower serum folate are more likely to suffer from insomnia. Vitamin B6 is found in sunflower seeds, pistachios, chicken, pork, and other foods, while sources of vitamin B12 include shellfish, seaweed, liver, mackerel, saury, and dried fish.
• Vitamin D: This vitamin helps with the synthesis of melatonin and is related to mood regulation, immune function, and sleep quality. Studies have found that vitamin D deficiency can lead to poor sleep quality, and supplementation may help improve it. He recommends taking vitamin D-related tests to determine whether you are deficient in it.

Melatonin Is Closely Related to the Intestines

In the past, it was thought that the pineal gland in the brain mainly secreted melatonin. However, in recent years, studies have found that the intestines can also synthesize substantial amounts of melatonin. The amount of melatonin in the intestine is 400 times more than that of the pineal gland.

Melatonin also regulates intestinal functions, including digestion and peristalsis. There is also an intimate connection between the intestines and the brain, called the “gut-brain axis.” When the body lacks melatonin, it affects our mood and sleep but could even affect intestinal peristalsis and, thus, digestion.

GABA Nutrients Aid Sleep

In addition to melatonin, He introduced another sleep-aid nutrient called gamma-aminobutyric acid (GABA). It is an inhibitory neurotransmitter that can suppress nerve excitement and help us relax physically and mentally.

GABA is found in some fermented foods, such as miso, kimchi, and pickled cucumbers. In addition, beans, tomatoes, and green tea also contain GABA. Cold-brewed green tea releases less caffeine and more GABA and theanine during steeping, which has a better relaxing effect.

Comparing GABA and Melatonin

Should people having trouble sleeping choose to supplement with GABA or melatonin? He said that different health products and nutrients are suitable for different types of insomnia.

1. Melatonin

Melatonin supplements are mainly used to dispel jet lag and help one fall asleep. Whether it is jet lag due to traveling or when your sleep-wake cycle is disrupted because of work or studies, when it becomes difficult to fall asleep at the normal time, you may consider supplementing with melatonin to help you fall asleep.

In addition, some children with autism and attention-deficit/hyperactivity disorder (ADHD) often have problems falling asleep. In these cases, seek evaluation from a psychiatrist to use melatonin or other drugs under the guidance of a physician.

2. GABA

Taking GABA is suitable for people with insomnia due to difficulty relaxing and anxiety, such as those with autonomic nervous system disorders, especially those with high sympathetic nerve activity and low parasympathetic nerve activity.

People who tend to be nervous, overthink, and find it difficult to relax, or those with poor sleep quality, such as difficulty falling asleep, waking up easily, shallow sleep, or having too many dreams, may find supplementing with GABA helpful.

Milk and Bananas to Help Sleep

Some people habitually drink a glass of milk before going to bed. Milk is rich in tryptophan. Studies have found that consuming tryptophan-rich dairy products at night will make you more alert in the morning.

However, He said that around 2 cups of milk is needed to achieve a sleep-inducing effect, and for some, drinking too much before going to bed might cause nocturia (needing to urinate at night) and affect sleep quality.

Although bananas do not have much tryptophan, they are rich in sugars that can help the brain relax and facilitate sleep. Many people feel physically and mentally relaxed when they eat a banana before bedtime, allowing them to fall asleep more easily.

Calcium and Magnesium Supplements Also Promote Sleep

Calcium deficiency is also one of the causes of insomnia. Milk is a useful source of calcium, but if you are concerned about nocturia, other calcium supplements are available.

Magnesium can further help our nerves and muscles relax and thus improve sleep quality. He recommends getting magnesium from nuts, chocolate, beans, avocados, and other foods.

Starch at Dinner Helps You Fall Asleep

He said dinner has the most impact on sleep quality. She recommends having your dinner, bath, and bedtime all properly arranged and ensuring you get adequate starch intake at dinner. Studies have found that eating starchy foods with a high glycemic index four hours before going to bed can shorten the time from lying down to falling asleep. This may be caused by the rise in blood sugar and insulin after dinner, making it easier for tryptophan to reach the brain and produce serotonin.

If you tend to feel hungry before bed, eat a small portion of starchy food, such as rice balls, bread, or cereal. These foods are easy to digest and slightly increase blood sugar to help you fall asleep. It’s important to avoid eating meat or fried or grilled foods before bed, as they are hard to digest and can put extra strain on the gastrointestinal tract, affecting sleep quality.