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Glutamine is the most abundant free amino acid in your body. However, it is not considered “essential.”
“Glutamine is called conditionally essential because the body can synthesize it in the liver, skeletal muscles and intestines,” says Jennifer Weis, RD, LDN. In other words, if you’re not eating enough, your body will generate it internally.
But eating too little glutamine isn’t a common issue because pretty much all animal proteins and plenty of plant-based foods contain enough of the stuff to keep the general population happy in the pink. However, most Oxygen readers don’t fall into gen pop, and for those hard-hitting lifters, endurance athletes and high-level competitive types who are regularly toeing that red line, a paucity of glutamine could be a thing.
Like all amino acids, glutamine is a building block of protein and helps create and maintain muscle tissue, but the benefits of it extend beyond those protein perks: Research published in Nutrition Reviews concluded that glutamine assists with cellular repair, and other studies indicate that a higher intake of glutamine is associated with a significantly lower risk of heart disease and all-cause mortality. It also helps your body produce immune-boosting cells, and it has been shown to prevent digestive issues such as leaky gut syndrome, diverticulitis and Crohn’s disease. A study in Clinical Immunology found that glutamine helps reduce intestinal inflammation, and another study in the journal Lancet found that glutamine decreases intestinal permeability.
Additionally, in the presence of cysteine and glycine, glutamine helps create glutathione, a powerful antioxidant responsible for boosting energy and immunity, and helps prevent age-related diseases such as cancer and dementia. Your brain also loves itself a little glutamine: It is a precursor to the neurotransmitter glutamate, and according to research published in Neuron Glia Biology, a lack of glutamate can cause anxiety, depression, alcohol addiction and even schizophrenia.
As it pertains to athletic types, glutamine has been studied for its recovery potential, and a study published in the Journal of Applied Physiology found that glutamine helps with muscle hydration and reduces your recovery time from training. And as you know, the faster you recover, the faster you can get back to training and the faster your performance will escalate.
So … Supplements?
Clearly, glutamine is important for all human beings, especially serious athletes. But should you be supplementing?
“A well-balanced diet with adequate protein from all sources (animal or vegan) provides enough glutamine … for healthy individuals,” says Aliz Alaman, RDN, CSSD, CDE, owner of Nourish Nutrition Counseling. “And since athletes typically consume higher protein diets than most of the population, if you meet your estimated protein needs, you should also be meeting your glutamine needs.”
Getting nutrients from real whole foods is always preferable to supplementation, and fortunately, glutamine is found in abundance in animal proteins such as meat, bone broth, cottage cheese, wild-caught fish and eggs and in plant-based sources like beans, spinach, asparagus and celery.
That being said, there are people who could be deficient, including those recovering from surgery, pregnant and lactating women, those with chronic stress and possibly elite or high-octane athletes. “Supplementation of up to 45 grams of glutamine daily appears to be safe, though not necessary, for healthy individuals and athletes,” Alaman says.
Get a Glut of Glutamine
Here are some of the top-tier foods that are high in glutamine.
|Seafood||Fish, mussels, shrimp, crab|
|Meat||Lamb, beef, organs, bone broth|
|Poultry||Chicken, turkey, eggs|
|Dairy||Milk, yogurt, ricotta cheese|
|Greens||Kale, spinach, cilantro, parsley|
|Vegetables||Asparagus, red cabbage|
|Legumes||Chickpeas, lentils, kidney beans, soybeans|