8 Essential Amino Acids for the Body

Proteins are involved in internal chemical processes: they help to create human body tissues and provide us with energy. Amino acids are the most actively involved in this process – they are the building blocks of proteins. They transmit signals inside cells, stimulate the production of hormones and enzymes, and can determine the quality of our lives.

The body synthesizes some amino acids by converting protein chains that come from food. However, there are nine essential amino acids that the body is unable to produce. They must be obtained from the diet or supplements every day. The essential amino acids include:

• Valine
• Isoleucine
• Leucine
• Phenylalanine
• Threonine
• Tryptophan
• Methionine
• Lysine

The recommended daily intake of each amino acid is indicated in the section for each amino acid, in the ratio of the amount of milligrams of amino acid per one kilogram (2.2 pounds) of body weight. To find out how much of each type to consume per day, multiply the numbers by your weight.

The highest concentration of amino acids is found in animal proteins. They are easier to absorb and are called “complete” because they contain all nine essential amino acids at once. Add meat, eggs, and dairy products to your diet, and your body will receive the necessary building materials. If you follow a vegetarian or vegan diet, it is worth including several types of “incomplete” plant proteins in your menu.

Amino acid manufacturing by private companies and the supplements they produce make it possible to obtain the necessary amount even in cases where the diet cannot be influenced due to diet or professional sports. Dietary supplements will be useful when the body’s needs are increased due to age or illness.

1. Valine

Norm: 24 mg/kg

Valine is a starting point for various tasks. The body uses this amino acid to:

• obtain energy;
• build and restore muscles;
• maintain a sufficient level of serotonin. This hormone is responsible for emotional stability and muscle tone;
• synthesize vitamin B5, which fights fatigue, stress, and insomnia;
• stimulate the work of growth hormone;
• produce insulin, which lowers blood sugar levels;
• strengthen immunity.

A lack of valine can cause growth disorders, especially in children, as well as coordination problems and muscle loss.

Foods with a high content of valine, from the highest concentration to the lowest:

• Meat: beef, veal, lamb, pork;
• Poultry: chicken, turkey, duck;
• Fish: tuna, salmon, tilapia, pike;
• Tofu;
• Dairy products: yogurt, milk, ricotta, Parmesan, goat cheese;
• Legumes: beans, lentils, green peas.

2. Isoleucine

Norm: 19 mg/kg

The body also uses isoleucine in various ways:

• Converts it into protein, glucose, or ketone bodies;
• Restores muscle tissue;
• Stimulates antibacterial processes in the intestines and the production of hemoglobin.

Most of the isoleucine accumulates in the muscles, preventing their breakdown during physical exertion. Athletes and children have an increased need for it.

Foods with high levels of isoleucine, from highest to lowest:

• Meat: beef, veal, lamb, beef, pork.
• Poultry: turkey, chicken, duck.
• Fish: tuna, salmon, tilapia, pike.
• Tofu.
• Dairy products: yogurt, ricotta, Parmesan.
• Legumes: beans.

3. Leucine

Norm: 42 mg/kg

Healing of wounds, tissue regeneration, and the production of growth hormones cannot be achieved without leucine. Moreover, this amino acid regulates serotonin production and counteracts fatigue.

Foods rich in leucine:

• Poultry: chicken, turkey.
• Meat: lamb, beef, pork.
• Seafood: tuna, salmon, tilapia, shellfish.
• Tofu.
• Legumes: beans, lentils.
• Dairy products: yogurt, cottage cheese, Parmesan cheese.
• Eggs.
• Nuts.

4. Phenylalanine

Norm: 33 mg/kg

This amino acid serves as raw material for the thyroid gland and adrenal glands:

• Becomes the core for the synthesis of thyroxine;
• Transforms into another amino acid – tyrosine;
• Converts into neurotransmitters: dopamine, epinephrine, and norepinephrine;
• Contributes to the production of melatonin – the sleep hormone;
• Affects the endogenous pain relief system, that is, it alleviates dull sensations.

Our alertness, ability to concentrate and react to stress depend on phenylalanine. You can replenish its reserves from such products:

• Meat: veal, lamb, beef, pork.
• Poultry: chicken, turkey, duck, goose.
• Tofu.
• Seafood: tuna, grouper, salmon, trout, tilapia, mackerel, shrimp, lobster.
• Legumes: beans, lentils, chickpeas, green peas.
• Dairy products: milk, yogurt, ricotta, parmesan, Swiss cheese.
• Seeds: pumpkin, sunflower, chia.
• Nuts: peanuts, pistachios, almonds, macadamia, cashews.
• Grains: wheat, quinoa, oats, brown rice, rye, barley.
• Sweet potato.

5. Threonine

Norm: 20 mg/kg

Threonine is a central element of elastin and collagen, which are responsible for the strength and elasticity of body tissues. This amino acid accumulates in the heart and skeletal muscles, as well as in nerve cells. When combined with others, threonine contributes to the breakdown of fats, has an anti-ulcer effect, and helps to produce antibodies. It reaches its highest concentration in the following foods:

• Meat: beef, lamb, pork.
• Poultry: chicken, turkey.
• Seafood: tuna, salmon, tilapia, mahi-mahi, sardines.
• Tofu.
• Legumes: beans, lentils.
• Dairy products: milk, soft cheese, yogurt.
• Vegetables: green peas, sweet potato, carrot, spinach.
• Eggs.
• Pumpkin seeds.

6. Tryptophan

Norm: 5 mg/kg

Tryptophan is another multifunctional amino acid:

• Only with its participation, the body produces niacin – vitamin B3;
• It is a chemical precursor of serotonin – a neurotransmitter that controls appetite, sleep, and mood;
• It is needed by the body for the synthesis of nicotinic acid.

Tryptophan indirectly controls the pain threshold level, helps regulate intestinal peristalsis, and resist inflammatory processes. In adults, taking tryptophan supplements reduces anxiety and helps to overcome sleep disorders, while for children, it is a guarantee of normal development. Products rich in tryptophan are:

• Poultry: chicken, turkey, duck.
• Meat: beef, lamb, pork.
• Tofu.
• Seafood: salmon, tuna, cod, tilapia, mahi-mahi.
• Beans.
• Dairy products: milk, cottage cheese, mozzarella, cheddar, parmesan, gruyere.
• Seeds: pumpkin, chia, flax.
• Grains: oats, quinoa.
• Eggs.

7. Methionine

Norm: 19 mg/kg

The functional load of methionine is also significant:

• The body synthesizes other amino acids from it: cystine, cysteine, and taurine, as well as choline – a vitamin from the B group, and adrenaline;
• It is a lipotropic substance: it promotes fat breakdown;
• With the help of methionine, the body absorbs zinc and selenium;
• This amino acid initiates the creation of new proteins inside cells, speeding up the processes of regeneration.

Methionine helps to remove toxins, improves the quality of cartilage tissue, nails, and hair. Taking dietary supplements is beneficial during pregnancy, drug intoxication, and weakened immunity. Methionine is abundant in such foods as:

• Poultry: turkey, chicken.
• Meat: beef, lamb, veal, pork.
• Seafood: tuna, grouper, salmon, tilapia, mahi-mahi.
• Tofu.
• Dairy products: milk, yogurt, ricotta, Parmesan, Gruyere.
• Brazil nuts.
• Beans.
• Quinoa.

8. Lysine

Norm: 38 mg/kg

Lysine promotes the absorption of calcium, the production of collagen and creatine. A deficiency of this amino acid leads to a decrease in the number of red blood cells and hemoglobin in them, as well as exhaustion of muscle and bone tissue. To avoid a deficiency, add to your menu:

• Meat: beef, lamb, pork.
• Poultry: chicken and turkey breast.
• Fish: tuna, salmon, tilapia, cod, mackerel.
• Seafood: king crab, lobster, octopus, shrimp.
• Tofu.
• Cheese: ricotta, Parmesan, Pecorino Romano, Gruyere, Gouda, provolone.
• Milk.
• Beans.

Meat, eggs, and dairy products will provide you with a complete set of essential amino acids. You can also add legumes, soy products, or nuts to your diet. And supplements from companies that have established private label amino acid manufacturing can help meet daily requirements even in cases where the demand is increased due to athletic activity, pregnancy, age, or illness.