Is L-Glutamine What Your Daily Diet's Been Missing?

When you’re deciding what to eat for dinner, chances are that you’re not thinking, “Mmm, L-glutamine sounds good!” You might not be familiar with this important amino acid, but it supports your immune system and is a major component in protein.

You’re probably getting some L-glutamine from your food choices. Here’s how to tell whether you’re getting enough—and whether you should try a supplement to support your health.

What is glutamine and why is it important?

Glutamine is one of the amino acids your body needs to function properly. While their main purpose is to help build proteins, they also help fight off viruses and bacteria and can help transport substances in your bloodstream. Glutamine has two forms: L-glutamine and D-glutamine. L-glutamine is the amino acid most commonly found in supplements and food—you may just see it referred to as “glutamine.” D-glutamine is relatively unimportant to humans, so there’s no need to be concerned that you’re getting enough D-glutamine, too.

Glutamine is important for your immune and intestinal health, but it’s also useful if you want to build muscle. Unlike some amino acids, your body can produce L-glutamine on its own. In fact, it’s the most abundant amino acid in the body—but illness and injury can make it difficult for your body to produce enough.

When you’re injured or sick, your body can’t produce enough glutamine on its own. Your body will instead break down your muscles to release enough of the amino acid to carry out its normal processes. That’s why it’s smart to make sure that you’re getting plenty of glutamine in your diet.

Benefits of glutamine

• Immune system support. Glutamine fuels your white blood cells and some intestinal cells, which make up part of your immune system. White blood cells are responsible for finding and fighting off bacteria and viruses, which can weaken the immune system and get you sick. If you’re starting to feel a cold coming on (or worse), make sure that you’re eating plenty of foods high in glutamine. You can also take a supplement during these times, if food is not your friend at the moment.
• Intestinal health. Does the phrase “leaky gut” strike fear into your heart? If you get enough glutamine, you’ll never have to worry about this horrifying—and dangerous—condition. Glutamine helps build the walls of your intestines, maintaining a healthy barrier. That prevents bacteria and other toxins from leaving the intestines and moving into other parts of your body. Your intestinal cells need glutamine for normal growth, so load up on protein.
• Helps you get (and stay) ripped. Sweet gains, bro—you must be taking your glutamine. Glutamine helps reduce muscle soreness and improve your recovery. In fact, it may also help ward off exercise-related fatigue, so that you can keep lifting until your heart’s content…or you’re just ready for a nap.

Where to get your glutamine fix

The average diet should contain about three to six grams of glutamine per day, depending on your specific needs. If you suffer from immune or intestinal disorders, you might want to talk to your doctor about whether you should take glutamine supplements. While glutamine probably won’t cause any side effects, it’s always wise to get an okay from a trusted medical professional.

Glutamine is most commonly found in protein, like eggs, beef, milk and tofu—but it’s also present in white rice and corn. In fact, tofu, rice and corn have the highest percentages of glutamine per 100g.

Since glutamine is common in proteins, just about any protein source will give you a glutamine boost. However, sometimes the amount is so small as to be negligible. Be sure to check the labels and supplement with additional glutamine when you’re sick.

The good news is that glutamine deficiency is extremely rare, and it’s caused by a genetic disorder. You’re probably getting enough glutamine if you eat recommended daily amounts of protein—but there’s always room for improvement, so be sure to talk to your doctor about your dietary needs. People who eat plant-based diets and have allergies to corn or soy may have a more difficult time meeting their nutritional needs.

The bottom line

L-glutamine is an important part of your immune system, muscle growth and intestinal health—and you can get it naturally from foods most people eat every day. If you’re feeling a cold coming on, consider adding a supplement to help boost your immune system.