麩醯胺酸:好處、用途和副作用

What is glutamine?

Glutamine is an amino acid. Amino acids are molecules that perform a variety of roles in the body.

Their main purpose is to serve as building blocks for proteins.

Protein is vital to organs. They also have other functions, such as transporting substances in the blood and fighting harmful viruses and bacteria.

Like many other amino acids, it exists in two different forms: L-glutamine and D-glutamine.

They are almost identical but have slightly different molecular arrangements.

The form found in foods and supplements is L-glutamine. Some supplements list it as L-glutamine, but others just use the broader term glutamine.

While L-glutamine is used to make proteins and perform other functions, D-glutamine appears to be relatively unimportant in living organisms.

L-Glutamine is produced naturally in your body. In fact, it is the most abundant amino acid in blood and other body fluids.

However, sometimes your body's need for glutamine is greater than its ability to produce it.

Therefore, it is considered a conditionally essential amino acid, meaning it must be obtained from the diet under certain conditions, such as injury or illness.

Additionally, glutamine is an important molecule for immune system and gut health.

Glutamine is found in many foods

Glutamine occurs naturally in a variety of foods. It is estimated that a typical diet contains 3 to 6 grams per day, but this may vary depending on your specific diet.

Due to their high protein content, they are found most in animal products.

However, some plant foods contain a higher percentage of protein.

One study used advanced laboratory techniques to determine the amount of L-glutamine in various foods.

Here is the percentage of protein made up of L-glutamine in each food:

  • Eggs: 4.4% (0.6g per 100g of eggs)
  • Beef: 4.8% (1.2 grams per 100 grams of beef)
  • Skim milk: 8.1% (0.3g per 100g of milk)
  • Tofu: 9.1% (0.6g per 100g of tofu)
  • White rice: 11.1% (0.3 grams per 100 grams of rice)
  • Corn: 16.2% (0.4 grams per 100 grams of corn)

Although some plant sources, such as white rice and corn, contain large amounts of protein composed of glutamine, they are quite low in protein overall.

Therefore, meat and other animal products are the easiest way to get large amounts of vitamins.

Unfortunately, the exact glutamine content of many specific foods has not been studied.

However, since glutamine is an essential component of protein, almost any food containing protein will contain some glutamine.

Focusing on getting enough protein in your overall diet is a simple way to potentially increase your glutamine intake.

important for immune system

One of the most important functions of glutamine is its role in the immune system.

It is an important source of fuel for immune cells, including white blood cells and certain intestinal cells.

However, its blood levels may be reduced due to severe injury, burns, or surgery.

If your body's demand for glutamine is greater than its ability to produce it, your body may break down protein stores, such as muscles, to release more of this amino acid.

Additionally, when glutamine levels are insufficient, the function of the immune system may be compromised.

For these reasons, a high-protein diet, a high-glutamine diet, or glutamine supplementation is often prescribed after a major injury such as a burn injury.

Studies also report that glutamine supplementation can improve health, reduce infections, and shorten postoperative hospital stays.

What's more, they have been shown to improve survival rates and reduce health care costs in critically ill patients.

Other studies show that glutamine supplements may also improve immune function in animals infected with bacteria or viruses.

However, there is not strong support for benefits in healthy adults, whose needs can be met through diet and the body's natural production.

It plays a role in gut health

Glutamine's benefits to the immune system are related to its role in gut health.

In the human body, the intestine is considered the largest part of the immune system.

This is because your gut is home to many cells with immune functions and trillions of bacteria living in your gut that can affect your immune health.

Glutamine is an important energy source for intestinal and immune cells.

It also helps maintain the barrier between the inside of the gut and the rest of the body, thus preventing leaky gut.

This prevents harmful bacteria or toxins from moving from the intestines to other parts of the body.

Additionally, it is important for the normal growth and maintenance of intestinal cells.

Since the gut plays an important role in the immune system, glutamine can benefit your overall immune health by supporting intestinal cells.

Effects on muscle growth and exercise performance

Because glutamine is a building block of protein, some researchers have tested whether taking glutamine as a supplement can improve muscle growth or athletic performance.

In one study, 31 people took glutamine or a placebo during six weeks of weight training.

By the end of the study, both groups had improved muscle mass and strength. However, there were no differences between the two groups.

Other studies have also shown it has no effect on muscle mass or performance.

However, some studies report that glutamine supplements can reduce muscle soreness and improve recovery after strenuous exercise.

In fact, one study found that glutamine or glutamine plus carbs can help reduce blood fatigue markers during a two-hour run.

It has also been used to try to boost immune function in athletes, with varying results.

Other studies have found that when carbohydrates and certain amino acids are added, it does not improve the recovery of carbohydrate stores (glycogen) in the muscles.

Finally, there is no evidence that these supplements are beneficial for muscle growth or strength. There is limited support for other effects, but more research is needed.

It's also important to note that many athletes consume large amounts of protein in their daily diet, which means they may consume large amounts of glutamine even without supplements.

Dosage, safety and side effects

Since glutamine is an amino acid that occurs naturally in the body and is found in many foods, there is no need to worry that normal amounts of glutamine are harmful.

It is estimated that a typical diet may contain 3 to 6 grams per day, but this amount may vary depending on the type and amount of food consumed.

Studies on glutamine supplements have used a variety of doses, from about 5 grams per day to high doses of about 45 grams per day for six weeks.

Although no negative side effects were reported at this high dose, no blood safety indicators were specifically examined.

Other studies report minimal safety concerns with short-term supplementation up to 14 grams per day.

Overall, it is thought that short-term use of supplements is probably safe. However, some scientists have expressed concerns about its continued use.

Adding glutamine to your regular diet can cause various changes in the way your body absorbs and processes the amino acid. However, the long-term effects of these changes are unclear.

Therefore, more information is needed about long-term supplementation, especially when using high doses.

If you eat a high-protein, animal-based diet, glutamine supplements may not have the same effect compared to a low-protein, plant-based diet.

If you follow a plant-based diet that is lower in glutamine, you may be able to take supplements while still getting your normal daily intake.

If you decide to take a glutamine supplement, it's best to start with a conservative dose of around 5 grams per day.

generalize

Glutamine is an amino acid that exists in two forms: L-glutamine and D-glutamine.

L-Glutamine is the important form that occurs naturally in the body and is found in many foods. It is estimated that a typical diet contains 3 to 6 grams per day.

It provides fuel for immune cells and intestinal cells and helps maintain strong connections in the gut.

When your body is unable to produce optimal amounts, such as during an injury or serious illness, supplementing it may benefit your immune health and recovery.

Glutamine is also commonly used as an exercise supplement, but most studies do not support its effectiveness.

Supplements appear to be safe in the short term, but more research is needed on their long-term effects.

Before taking glutamine supplements, consider whether current evidence supports the reasons for taking them.

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