Amino Acids 101

When hearing about proteins and amino acids, many of us have to think back to our middle school science classes. A swarm of polypeptides diagrams dance in our heads, and their meanings begin to escape us. As adults, it’s definitely worth revisiting the basics to see how these proteins fit into our lifestyles and how they can improve our bodies.

The Breakdown
According to nutrition expert Keri Marshall, M.S., N.D., proteins make up approximately 20% of our total body weight (1). Proteins are made up of smaller units called amino acids, of which 20+ have been identified. Humans can produce only around half of these acids, known as non-essential acids, while the others must be obtained through diet or supplements. Upon consumption, don’t expect a high-protein meal to add significant levels of amino acids in the bloodstream immediately. Instead, this process isn’t completed until hours after eating (2).

Once digested, protein synthesis can only occur if there are an adequate amounts of essential and non-essential amino acids. The assembled proteins are broken apart, allowing the amino acids to enter the bloodstream. Any aminos not used immediately are sent to the liver and are eventually excreted. The remaining protein is converted into glucose and used as energy. Any excess is converted to fat or glycogen for additional storage.

Amino Acids’ Many Functions!
Amino acids are well-known for their muscle recovery and overall workout benefits. Branched chain amino acids (BCAAs) like leucine, for instance, are needed for muscle recovery and prevent the breakdown of muscle proteins after strenuous activities.

But it would be a mistake to think aminos are just for athletes. Leucine is crucial for hemoglobin formation, and promotes healthy blood sugar levels. Plus, small studies found that patients given BCAAs while undergoing dialysis had an easier time breathing and sleeping. If given a regular dose of BCAAs, children suffering from phenylketonuria had better test scores and improved mental functioning (1).

Another essential amino acid is lysine, which can help cholesterol, bone and heart health, as well as support muscle recovery. Its first major function is the production of carnitine, which converts fatty acids into energy, benefits hearth health and boosts exercise performance. Lysine also helps in the production of collagen, a protein that makes up cartilage, tendons, ligaments and bones in the body. Staying on the topic of bones, lysine aids in the body’s absorption of calcium (3).

While supplements don’t treat diseases, those with herpes and viral diseases may benefit from a high-lysine, low-arginine diet, with a doctor’s permission. This is because the amino blocks arginine, a semi-essential amino acid that promotes HSV replication.

Though smaller amounts of arginine benefit those with viral diseases, our bodies need it to promote fertility, heart health, waste production and more. As a semi-essential amino acid, it is produced by the body, but at lower levels than others, forcing us to look elsewhere for a more abundant supply. A person with arginine deficiency can suffer from constipation, alopecia and skin problems. Our bodies need this acid because it makes urea, a waste product that our bodies discard when we urinate (4).

Arginine helps the body produce creatine, which contributes to muscle mass and strength. As a supplement, arginine can act as a vasodilator, dilating blood vessels which allows for more blood to pass through. Lowered blood pressure can help the body prevent arterial blockages caused by diseases like atherosclerosis. The opening of blood vessels also plays a role in fertility, because it helps increase blood flow to all organs of the body, especially ones used in reproduction. According to a report done by Steven Sinclair, ND, Lac, arginine may help with sexual dysfunction by increasing sperm motility, which describes their ability to move toward an egg (5).

Last, arginine promotes heart health. When taken in supplement form it can also help with healthy circulation, especially in the legs.

There are only two semi-essential amino acids, the second being histidine. Some research has shown that people suffering from rheumatoid arthritis have lower levels of histidine, which could be helped through supplementation (1).

Ease Your Mind!
We have covered amino acids that help with our physical processes, but what about our mental ones? An essential amino acid called methionine may help. This sulfur-containing amino acid is needed to regulate our growth and metabolism. Methionine deficiency can lead to cognitive problems, dementia and cardiovascular disease. According to one clinical trial, when given in doses of 400 mg four times a day, methionine served as a better treatment for depression than traditional ones such as MAO inhibitors and tricylic antidepressants (1).

We are barely scratching the surface when it comes to amino acids, but the ones mentioned in this article are worth exploring. Who’d have thought those lectures in science class from yesteryear would still be applicable to our lives today? WF

1. K. Marshall, User’s Guide to Protein and Amino Acids (Basic Health Publications, Laguna Beach, CA, 2005).
2. “The Chemistry of Amino Acids,”, accessed Aug. 8, 2012.
3. University of Maryland Medical Center. “Lysine,”, accessed Aug. 8, 2012.
4. E. Duse, “L-Arginine: What You Need to Know,”, accessed Aug. 8, 2012.
5. S. Sinclair, “Male Infertility: Nutritional and Environmental Considerations,”, accessed Aug. 8, 2012.

Published in WholeFoods Magazine, October 2012