Glutamine: What You Need to Know (from a Sports Nutritionist)

To supplement or not to supplement? Find out here!

Glutamine might not be the first thing you think of when it comes to health and fitness, but this powerhouse amino acid plays a vital role in keeping your body running smoothly. From supporting your immune system to aiding gut health and even assisting in muscle recovery, glutamine pulls its weight in ways you may not realize. Curious about whether you’re getting enough or if this supplement is worth it for you? Let’s break it down! 

Key Take Aways

• Glutamine is the most abundant amino acid in your body, essential for immune function, gut health, and protein production. 

• While generally non-essential, glutamine may become necessary during times of stress, illness, or intense physical activity. 

• Foods like meat, dairy, beans, and certain vegetables are excellent natural sources of glutamine. 

• Glutamine supplements may be worth the $$ for high level athletes during intense bouts of training to support recovery and reduce muscle soreness, but they are not essential for most healthy adults with a balanced diet who exercise. Save your money! 

What is glutamine? 

Glutamine is the most abundant amino acid found in the body, making up about 60% of the amino acid pool in skeletal muscle. It is primarily produced in the muscles and brain, with additional production occurring in the lungs, liver, and fat tissues. Glutamine travels through the bloodstream to various organs, such as the intestine and immune cells. Glutamine is used as a building block for making proteins in the body and is an important part of the immune system and intestinal health.  

Check-in: Remember, proteins are vital to body organs and serve many functions, such as structural support, transporting substances in the blood and fighting off harmful viruses and bacteria as initiators of cell death. 

Although glutamine is the most abundant amino acid found in the body, it is also a conditionally essential amino acid. Have you ever wondered why glutamine is a ‘conditionally essential’ amino acid? It is because our bodies don’t normally need it from our diet. Typically, your body can produce enough glutamine to supply your needs. However, research has shown there are times when the glutamine needs of your body are far greater than its ability to produce it, which include conditions such as stress, trauma, muscular dystrophy, and/or illness. 

Why is glutamine important? 

1) Immune System Support 

Most notably, glutamine is a crucial amino acid that helps keep your defenses up! Glutamine is a primary energy source for immune cells such as lymphocytes and macrophages. Intense physical activity, illness, or injury can deplete glutamine levels, weakening immune function. 

2) Gut Health and Digestion 

Glutamine is essential for the health of your intestinal lining. It helps maintain the integrity of the gut barrier, preventing leakage of toxins and bacteria from the gut into the bloodstream. It also supports your cells that line the intestines to ensure efficient digestion and absorption of nutrients, which is crucial for your overall well-being and energy levels.

3) Brain Function and Cognitive Health 

Glutamine is a precursor to the neurotransmitter glutamate, which plays a critical role in cognitive function, memory, and learning. Interestingly, it helps produce energy and support communication between neurons in the brain. 

4) Protein Synthesis and Muscle Recovery 

Although the above three roles of glutamine are vital to daily function, sports performance and recovery from training/exercise, in this section we are getting to the fun part for trainers, athletes and exercisers (and what many of you may have come to this page for). Glutamine is involved in protein synthesis, the process by which the body builds new proteins, including muscle tissue. After exercise, muscle fibers undergo stress and damage, and glutamine helps repair and rebuild these fibers, facilitating muscle recovery and growth. 

Glutamine also helps counteract the breakdown of muscle tissue (catabolism) by maintaining an anabolic environment (muscle-building).  

Does glutamine help with reducing muscle damage and/or soreness after intense training? 

Maintaining and improving athletic performance and recovery is an area that is constantly considered by trainers, athletes, and recreational exercisers. Nowadays, athletes and recreational exercisers employ several approaches for success in sport, competitions and in the gym including supplementing with pharmaceutical or nutritional products. So, many athletes or exercisers are probably asking, is glutamine supplementation going to help me recover and/or reduce soreness after intense bouts of training? Is it worth my money? 

Glutamine is currently part of clinical nutrition protocols and/or recommended for immune suppressed individuals. However, when the body is breaking down more tissues, like muscle, at a faster or more excessive rate than usual or in high-stress states like post high-intensity resistance training, research is still unclear.  

Scientifically, the immune system is necessary for recovery from states when the body is breaking down muscle or fat tissue at high rates including stress. So, glutamine may help during intense and prolonged physical exercise by playing a role in: 

• Normalizing growth hormone 

• Promoting glucose uptake after workouts 

• Enhancing the hydration state of a muscle 

• Reducing acid buildup with exercise  

Some studies support glutamine supplements decreasing muscle soreness and improving recovery after intense exercise, and other studies show boosting the immune function of athletes. The benefits for healthy individuals who are engaging in regular training are somewhat debated.  

It doesn’t appear that intense training or exercise will decrease glutamine concentrations enough to compromise recovery in a healthy adult. This is specific to people who consume adequate energy in the form of protein and carbohydrates where they tend to have naturally high glutamine intake even without supplements.

Where do we consume glutamine? 

Foods high in glutamine: 

• Meat: Beef, pork, and poultry 

• Fish and seafood 

• Dairy: Milk, yogurt, ricotta cheese, and cottage cheese 

• Protein-rich non-animal products: Nuts and tofu 

• Vegetables: Corn, cabbage, and leafy greens 

• Grains: Rice and oats 

Eastern Europeans it’s time to celebrate! You have another reason to encourage your family and friends to eat the buraczki, borscht and holubtsi! We consume on average 3 to 6 grams daily in the diet, meeting the body’s needs. 

Glutamine supplementation: 

Typically, consuming individual amino acids, like glutamine, in high doses could hinder the absorption of other amino acids. Glutamine supplements, however, appear to be absorbed adequately and don’t cause gastrointestinal distress. 

What is the right dosage for glutamine supplements? 

Several studies such as this study and this study on glutamine supplements have used a wide variety of doses, ranging from 100 mg pre-exercise, during exercise, and post-exercise to higher doses of 28 grams every day for 14 days. There are no harm or ill-effects reported with high doses, but blood safety markers are often not examined in these studies. Short-term use of 5 to 10 grams is likely safe.  

But what if you consume an animal-based, high protein diet? Then it is most likely that glutamine supplements may not have the same effects compared to a plant-based, lower-protein diet. So, if you follow a plant-based diet with low glutamine content, you may want to consume supplements while still receiving a normal daily amount overall. 

If you decide to take a glutamine supplement, it is best to start with a conservative dose of around 5 to 10 grams per day in the L-glutamine form. L-glutamine is the active form found in food and supplements. 

When should I take a glutamine supplement? 

Everyone is unique in their responses to a supplementation protocol. However, consuming glutamine post workout is commonly practiced helping support muscle protein synthesis, enhance immune function, and help increase glycogen synthesis for subsequent sessions. 

What glutamine supplements are the best? 

Unfortunately, glutamine supplements are not regulated like food. They are under the Natural Health Products act, meaning there is very little regulation around them. So, to ensure your safety, I recommend taking supplements that have been third party tested by NSF for Sport or Informed Choice.  

It’s always a good idea to consult with a healthcare provider or Registered Dietitian before adding any new supplement to your regimen so they can consider your goals, body size, and activity level. 

Glutamine is a key amino acid in the body that is essential for several physiological functions, including muscle recovery, immune function, gut health, and cognitive performance. While the body can produce it under normal conditions, high-intensity exercise, stress, illness, and injury can increase the body’s demand for glutamine.  

For most people engaging in moderate exercise, glutamine supplementation is likely not necessary since the body typically produces enough. If you’re engaging in heavy and intense training or experiencing periods of stress, illness, or injury, glutamine supplementation may be beneficial to optimize muscle recovery and support your body’s needs. Still, if you consume a diet high in animal-based proteins, fish and seafood, dairy, nuts and certain vegetables (i.e., cabbage, leafy greens) then you likely have your glutamine bases covered.   

If you want to try supplementation, it’s always a good idea to consult with a healthcare provider or Registered Dietitian to determine if glutamine supplementation is right for your specific needs. 

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