9 Essential Amino Acids

You hear the term amino acids often.  But what do they do and why is everyone concerned with them? There are over 20 types of amino acids which are used to form proteins.  However, the most well-known types of amino acids are known as “essential amino acids.” These amino acids cannot be produced by the body they must be consumed from food.  Below is a list of the essential amino acids, the functions they serve, and how to get them.

1. Histidine

Histidine is used to develop and maintain healthy tissues throughout the body and work with myelin, a fatty material that protects and insulates the nerves, to make sure information is transferred from the brain to various parts of the body.  In order for the body to be healthy, histidine levels must be balanced.  Mental disorders such as anxiety and schizophrenia have been observed in individuals with a histidine imbalance.  Histidine is also involved in sexual functioning, as histidine converts into histamine, the amino acid responsible for sexual arousal.  Histidine is found in protein rich products such as dairy products and poultry.  

2. Isoleucine

Isoleucine is known to increase endurance while also helping to heal or repair damaged muscle tissues.  The main function of this amino acid is allowing the body to recover after strenuous exercise.  In addition, it keeps energy levels stable, which helps regulate blood sugar.  A deficiency in isoleucine can lead to issues such as headaches, dizziness, irritability, depression, and confusion.  Some great food sources of isoleucine include nuts, seeds, meat, eggs, fish, lentils, peas, soy, and also available as a supplement.

3. Leucine

Leucine works with isoleucine to help repair muscles, increase energy levels in the body, and regulate blood sugar.  On its own leucine increases growth hormone, and burns fat.  Leucine is combined with isoleucine and valine, to form the branched-chain amino acids (BCAA) and they work together to perform many functions in the body.  Leucine is the most effective BCAA for muscle loss as it is broken down and converted to glucose quicker than both isoleucine and valine, which leads to healthy blood sugar levels.  Leucine is commonly found in t, brown rice, beans, meat, flour, nuts, and whole wheat.  Leucine, like isoleucine is available as a supplement as well.

4. Valine

Valine is the third branched chain amino acid that works with leucine and isoleucine to repair tissues, promote muscle growth, and provide the body with energy. However, valine also helps stimulate the central nervous system and maintain healthy mental function.   A deficiency of valine can cause degenerative neurological conditions.  Valine helps remove toxic chemicals from the liver and transports nitrogen to other organs in the body, which helps treat liver and gallbladder disease and damage caused to these organs by alcoholism and drug abuse.  While valine is available on its own through supplementation, it works best when combined with the other two BCAA, isoleucine and leucine.

5. Lysine

Lysine is most known for its antiviral effects.  Lysine is involved in the production of antibodies to create a healthy, strong immune system.  also why it is effective in protecting against herpes.  In addition, this amino acid forms collagen and muscle protein, which helps speed recovery from surgery.  Good sources of lysine are milk, eggs, cheese, fish, red meat, lima beans, and potatoes.  

6. Methionine

Methionine helps the body process and get rid of fat.  It also helps produce two important amino acids, cytosine and taurine, and together they help eliminate toxins from the body, build strong bones and tissues, and promote heart health.  Methionine makes creatine, a nutrient found in muscle tissue that provides our muscles with the energy they need to move and is necessary for all muscle function.  Methionine has been shown to help with symptoms of pancreatic cancer, Parkinson’s disease, and urinary tract infections.  This amino acid can be found in eggs, beans, garlic, onions, lentils, soybeans, and yogurt.

7. Phenylalanine

Phenylalanine is possibly the most important amino acid that your body needs.  One of the main functions of phenylalanine is to ensure that the central nervous system is working properly.  Some of its other uses are to control symptoms of depression and chronic pain.  Our body needs phenylalanine to make epinephrine, norepinephrine, and dopamine, three very important neurotransmitters that are responsible for how you interact with your environment.  There are three different types of phenylalanine:

1. L-phenylalanine: responsible for regulating mood and appetite

2. D-phenylalanine: effective for controlling pain

3. DL-phenylalanine: affects pain sensitivity and mental state

L-phenylalanine is the only form that is found in food and is found, like most amino acids, in products with high protein content like dairy products, poultry, fish, beef, and soy   

8. Threonine

Threonine is an amino acid that is responsible for maintaining the proper protein balance in the body.  Threonine is necessary for making glycine and serine, two other amino acids that are involved in the production of collagen, elastin, and muscle tissue.  These amino acids combine to keep connective tissues and muscles in the body strong, including the heart.  Without sufficient threonine in the body, fats can accumulate in the liver and lead to liver failure.  Dairy foods, meats, mushrooms, leafy vegetables, and whole grains all contain threonine.  It is also available in supplement form and threonine supplementation may limit some of the symptoms of Lou Gehrig’s disease (also known as ALS), and multiple sclerosis.

9. Tryptophan

Tryptophan is probably one of the most well-known amino acids.  Tryptophan has been used for a wide variety of illnesses including sleep apnea, insomnia, depression, anxiety, and ADHD.  Your body also uses tryptophan to make proteins, vitamin B-3 (niacin), serotonin, and melatonin.  Due to its ability to create serotonin and melatonin, two of the main neurotransmitters involved in sleep, tryptophan has been heralded as an effective sleep aid.  You’ve probably heard that the reason you are tired after eating a big turkey dinner on Thanksgiving is because of the high levels of tryptophan.  Along with turkey, tryptophan is also included in dairy products, meat, seeds, and nuts.

Amino acids are extremely important to our bodies for a wide variety of reasons, and the good news is that even though we can only get “essential” amino acids from the food we eat, it is found in many different foods.  Essential amino acids are also available as supplements there are plenty of ways to make sure you get enough of them into your body.