We call these amino acids “nonessential,” but it doesn’t mean that they are not needed or any less important than essential amino acids! Your body works its magic to create nonessential amino acids on its own, so it’s not as important to get them from an outside source.
Nonessential amino acids serve many functions in creating optimal health. While the following are classified as nonessential amino acids, people with metabolic diseases or those who suffer from malabsorption syndromes may be deficient in these amino acids and might need to pay special attention and ensure they are consuming adequate quantities.
1. Alanine – Brain Health and Much More
Alanine is essential for proper function of your central nervous system. This means your brain needs it to function properly. It is also plentiful in human muscle tissue and is readily converted to glucose for energy when blood sugar levels fall. During exercise, your muscles release Alanine into your bloodstream in direct proportion to your level of exertion. It is then converted into blood sugar and released into the blood plasma. Hence, Alanine may help keep your blood sugar levels stable during exercise. Alanine stimulates lymphocyte production and may help people who have immune system disorders. It is also present in prostate fluid, where it may play a role in supporting prostate health.
Animal sources: salmon, cod and most fish, seafood, beef, milk, cheese, eggs, gelatin found in homemade broths or stocks
Plant sources: legumes, nuts, seeds, brewer's yeast, brown rice, whole grains
2. Arginine – Nature’s Viagra®
Arginine is sometimes referred to as an essential amino acid and, at other times, it’s referred to as nonessential. This confusion happens because most of the time, your body can manufacture Arginine, so you don’t need to obtain it through your diet, but other times, you do! This is why it is considered to be conditionally essential.
An example of when you do need to obtain it in your diet in the case of severe injury or illness. Arginine plays an important role in cell division, the healing of wounds, and the release of hormones. It is also useful in enhancing the immune system. For this reason, Arginine might be important for people suffering from AIDS and other diseases that suppress the immune system. Arginine is also known to increase blood flow to the penis, making it a potential “natural” Viagra® and has also been used in treating sterility in men by increasing sperm count.
Animal sources: eggs, beef, pork, wild game, chicken, turkey, wild pheasant, quail, tuna, salmon, shrimp, cod, halibut, smelt, milk, cottage cheese, yogurt
Plant sources: almonds, walnuts, hazelnuts, Brazil nuts, cashews, pistachios, sunflower seeds, pumpkin seeds, flax seeds, lentils, chick peas, kidney beans, garlic, onion, seaweed, spirulina (a type of algae), buckwheat, oatmeal
3. Asparagine – Emotional Balance
Asparagine was named after discovery of the compound in asparagus juice. Ever notice the pungent smell of your urine after eating asparagus? This is attributed to various byproducts of Asparagine. This amino acid helps your nervous system maintain proper emotional balance. If your body fails to produce proper levels of Asparagine, your nervous system will be adversely affected. This may show up as headaches, confusion, and a noticeable increase in irritability, forgetfulness, and even the onset of depression.
Animal sources: beef, poultry, eggs, fish, seafood, dairy
Plant sources: asparagus, potatoes, legumes, nuts, seeds, whole grains
4. Aspartic Acid – Energy and Metabolism
Aspartic acid helps keep the brain alert. It also removes harmful substances from your liver and helps increase your metabolism. People who don’t have enough animal protein in their diets may also have lower levels of Aspartic Acid, since meat is a top source of this type of acid. People who have low Aspartic Acid levels may also suffer from extreme fatigue and depression [II].
Animal sources: eggs, cod, whitefish, tuna, smelt, anchovies, pork, turkey, beef, veal, meat, wild game, some dairy
Vegetable sources: sprouting seeds, sunflower seeds, pumpkin, oat flakes, avocado, asparagus, young sugarcane and molasses from sugar beets, brewer’s yeast, parsley
5. Cysteine – Detoxification
Cysteine is an essential part of an antioxidant compound that helps protect cells. It assists in removing chemicals and heavy metals from body tissue. It also helps break down extra mucus in the lungs, making it important in the treatment of respiratory problems such as asthma. Cysteine is a component of beta-keratin, a main protein in your nails, skin, and hair. It is also believed to preserve skin elasticity, protect the lining of the digestive system, and help build your immune system.
Animal sources: egg yolks, poultry, pork, duck, milk, ricotta, cottage cheese, yogurt
Plant sources: red peppers, garlic, onions, lentils, oats, dark leafy vegetables
6. Glutamic Acid – Memory
Glutamic acid has many functions in the body, including building muscle, but it is most important in brain function, as it plays a key role as a main neurotransmitter in the nervous system. It is important for learning, memory, and brain function.
Animal sources: beef, fish, eggs, poultry, dairy, eggs, pork, veal, beef, cod, whitefish, Parmesan cheese, buttermilk, milk
Plant sources: sunflower seeds, pumpkin seeds, seaweed, spirulina, mustard seed
7. Glutamine – The Ultimate Gut Healer
Glutamine is the most abundant amino acid in the human body. It is found in large amounts in your body’s muscles. Since it easily passes through the blood-brain barrier, Glutamine is known as a super-fuel for your brain! Glutamine also serves as a source of fuel for the cells that line your intestines. By nourishing these cells, glutamine helps keep your digestive system healthy, which makes it easier for your body to absorb the nutrients in the food you eat. It is often used to heal the gut of those with leaky gut or digestive issues. Glutamine also reduces healing time after operations and for burn victims. Cancer and other diseases or injuries can cause a person to have a glutamine shortage. Unfortunately, chemotherapy and radiation therapy used to treat cancer often make this shortage worse. Therefore, Glutamine is sometimes described as a conditionally essential amino acid because it may need to be supplemented during times of injury or illness.
Animal sources: beef, chicken, fish, eggs, milk, dairy products
Plant sources: wheat, cabbage, beets, beans, spinach, parsley
8. Glycine – Brain Function
Glycine is the simplest of the 20 amino acids. It plays a major role in brain function. Glycine has shown some promise for use in the treatment of schizophrenia and may have other uses related to the brain [I]. Are you starting to see that amino acids are critical for brain health and mental clarity?
Animal sources: turkey, pork, chicken, eggs, beef, liver, game meat, whitefish, smelt, cod, dairy products
Plant sources: legumes, sesame seeds, seaweed, spirulina, brewer’s yeast
9. Proline – Younger Looking Skin
Proline is necessary for your body to produce collagen, which is the main protein of your skin, tendons, cartilage, bones, and connective tissue. It keeps your muscles and joints flexible and helps reduce the sagging and wrinkling associated with normal aging of the skin and exposure to sunlight. Proline helps repair damaged tissues, skin, and muscles. Endurance runners and competitive bodybuilders often lack Proline, which can lead to a decrease in muscle tissue.
Animal sources: beef, liver, game meat, poultry, eggs, pork, turkey, cheese, milk, dried beluga whale meat, cod, whitefish, smelt
Plant sources: mustard seed, poppy seeds, sunflower seeds, seaweed, spirulina, brewer’s yeast
10. Serine – Natures Anti-Depressant
Serine helps your brain and central nervous system function correctly. This amino acid also aids in the production of cells that help your body fight infections. In addition, your body uses Serine to make tryptophan and serotonin, which help your brain regulate your mood. Depression and anxiety have been linked to a lack of serotonin or tryptophan in the body.
Animal sources: eggs, gelatins, smelt, beluga whale meat, whitefish, milk products, elk, buffalo, game meat, pork, beef, turkey, lamb, salmon, veal, liver
Plant sources: seaweed, spirulina, sesame seeds, pumpkin seeds, brewer’s yeast, mixed nuts, lima beans, mung beans
11. Tyrosine and Stress
Tyrosine helps regulate mood and stimulates your central nervous system. Tyrosine is a building block for important brain chemicals known as neurotransmitters. Tyrosine may also help your body adapt to and cope with the effects of physical or mental stress by reducing the symptoms of stress.
Animal sources: eggs, cheese, milk, whitefish, smelt, cod, salmon, beluga whale meat, pork, turkey, beef lamb, veal, elk, game meat, liver, goose, duck
Plant sources: seaweed, spirulina, sunflower seeds, pumpkin seeds, parsley, brewer’s yeast
...Have you started to notice a pattern?
A lot of the same plant and animal sources are listed numerous times. That’s because these foods contain more than one type of amino acid. For this reason, Good Decisions considers them “all-star” proteins. Incorporating foods like sunflower seeds, pumpkin seeds, cod, salmon, eggs, legumes, game meat and, yes even grass fed beef on a regular basis, will give your body the building blocks it needs to provide you with a constant flow of energy throughout your day. I'm sure we could all use more of that! Mental clarity, younger-looking skin, increased memory and metabolism, as well as healthy sexual function, all depend on eating healthy, good quality proteins.
We place an emphasis on quality because it is easy to see how feeding the body synthetic proteins, proteins injected with food dyes, additives, preservatives, growth hormones, and antibiotics could adversely affect all of the bodily functions that require clean, healthy, natural protein.
Browse our All-Star Foods section to learn more about our favorite whole food sources of protein!
[I] Heresco-Levy U, Javitt DC, Ermilov M, Mordel C, Silipo G, Lichtenstein M. "Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia."Arch Gen Psychiatry. 1999. Jan; 56(1):29-36. Web. May. 2016. <http://www.ncbi.nlm.nih.gov/pubmed/9892253>.
[II] Paul IA, Skolnick P. "Glutamate and depression: clinical and preclinical studies." Ann N Y Acad Sci. 2003 Nov; 1003:250-72. Web. May. 2016. <http://www.ncbi.nlm.nih.gov/pubmed/14684451>.