Amino Acids: The Body’s Building Blocks of Protein

Most people have heard the statistic that their bodies are 60 percent water; however, did you also know that 20 percent of your body is made of protein? Proteins are like the construction crew in your body. They transport substances, build others, and convert energy to help your body’s mechanical processes.

Amino acids are protein’s building blocks. Your body needs 20 of them to help it function properly, as well as build and repair itself.

What Are Essential Amino Acids?

There are two types of amino acids: essential and nonessential. The human body does not produce these proteins, even though they are vital to sustain human life. This means you must get them in the protein found in plant and animal food sources.

The eight essential amino acids are:

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

In addition to these eight, there is histidine. Technically, it belongs on the nonessential amino acid list. However, children’s bodies do not create enough histidine and therefore must supplement through diet.

Foods rich in Isoleucine

Milk & Dairy
Eggs
Chicken
Beef
Pork
Nuts & Seeds
Legumes, Peas, Beans, & Peanut butter

Foods rich in Leucine

Parmesan Cheese
Soybeans
Chicken Breast
Tuna Fish
Beef
Nuts
Soybeans

Foods rich in Lysine

Lean Beef
Pork
Parmesan Cheese
Turkey & Chicken
Tuna Fish, cooked
Eggs
White Beans

Foods rich in Methionine

Fish & Shellfish
Parmesan Cheese
White Beans
Eggs
Turkey & Chicken
Lean Beef
Lamb

Foods rich in Phenylalanine

Parmesan Cheese
Dairy
Lean Beef & Lamb
Eggs
Pinto Beans
Soybeans
White Beans

Foods rich in Threonine

Turkey & Chicken
Parmesan Cheese
Lean Beef & Lamb
Fish & Clams
Nuts
White Beans
Soybeans

Foods rich in Tryptophan

Seed & Nuts
Lamb
Chicken & Turkey
Fish & Crab
Beans
Beef
Soybeans

Foods rich in Valine

Dairy, Cheese, & Eggs
Seeds & Nuts
Fish
Pork
Beef
Beans
Chicken & Turkey

Foods rich in Histidine

Fish
Pork
Beans
Eggs & Dairy
Seeds & Nuts
Turkey & Chicken
Soybeans

Not all of these sources are equal. Some have greater amounts of protein at a higher biological value, particularly those proteins from animals. Of course, that doesn’t mean that you can’t get the proteins and amino acids you need from a vegetarian diet. What it does mean is that you need to combine different sources that complement each other. For example, beans and toast complement each other to help your body more efficiently absorb the proteins found in beans.

What Are Nonessential Amino Acids?

Your body naturally produces the nonessential amino acids. When you enjoy good health, your body’s production is enough to maintain homeostasis (that is, a constant state). However, illness and stress, as well as a diet low in the essential amino acids, inhibit your body’s ability to produce adequate amounts of nonessential amino acids.

The nonessential amino acids include:

• Alanine
• Arginine
• Asparagines
• Aspartic acid
• Cysteine
• Glutamic acid
• Glutamine
• Glycine
• Proline
• Serine
• Tyrosine

Following a diet high in quality protein helps ensure your body creates these nonessential amino acids. Again, amino acids are how your body builds protein. They also help you absorb essential nutrients and digest your food.

How Does Your Body Use Protein?

It might be easier to say how your body doesn’t use proteins. Proteins help keep fluids and acids in balance; they transport oxygen to your cells; act as antibodies, enzymes, and hormones; and feed vitamins and minerals to your cells.

Proteins such as collagen and keratin build bones, hair, skin, and teeth. They work as the maintenance crew on tissues such as blood vessels. Other proteins take your body’s energy and use it contract your muscles and divide cells.

The proteins that facilitate chemical reactions are called enzymes (proenzymes in their inactive state). Proteins also carry messages throughout the body. Hormones such as insulin, for example, regulate blood glucose levels.

Protein molecules also form the antibodies that fight infection due to virus or bacteria. At the same time, they help your body maintain proper fluid balance between its three fluid compartments:

• Extracellular, or outside the cells
• Intracellular, or within the cells
• Intravascular, or within the blood

If fluid in these compartments goes out of balance, the body ceases to function properly. This includes both fluid levels and the pH of said fluids. A pH of 7.4 is neutral. As that number drops, acidity rises and vice versa. Your body works to keep blood pH as close to 7.4 as possible.

What Are Popular Sources for Protein and Amino Acids?

The average American has little trouble getting adequate protein through his or her diet, as animal-based foods are a rich source of amino acids. This includes beef, chicken, dairy, eggs, fish, and pork.

However, numerous plant-based sources also offer the proteins necessary for optimum health. Good sources include dried beans such as black and kidney beans, nuts, peas, seeds, and soy. To ensure your also get the essential amino acids your body needs, consume whole grains along with these plant-based proteins. You may also combine legumes with nuts and seeds.

The Health Benefits of Protein and Amino Acids

Deficiencies in either amino acids or proteins lead to a variety of chronic and acute health problems. For example, amino acid deficiency leads directly to a breakdown in muscle, hormone deficiency, and a weaker immune system.

Fluid imbalance also causes a variety of chronic health problems, chief among them heart disease. Fluid retention causes a buildup of blood, which strains blood vessels and forces the heart to work harder. It also puts a strain on kidneys, leading to kidney disease. In addition, proteins help transport fats through the bloodstream. Protein deficiency inhibits this flow and leads to fat deposits on the body.

A healthful diet is one that includes rich protein sources. Lean meats, dairy, and eggs are excellent sources. Beans and legumes make terrific plant-based sources. For other ideas on increasing protein intake, talk to your healthcare provider.