Protein, Separating Facts from Fads

Dear Dr. Suzy,   

Q. What is the big deal about dietary protein and why do I hear so much about it recently?

A. Lately, one of the three macronutrients has been receiving quite a bit of press, and also more than its fair share of controversy.  If you are confused by all of the information and misinformation swirling around concerning dietary protein, perhaps it is a good idea to learn the basic facts about this popular subject and then form your own opinion.  As you have found thus far on your Pura Vida journey, the more you know, the easier it is to sort out the truth from the hype.

Since protein is found in every cell of your body, it is a vital nutrient for all bodily functions. In essence, your whole body is made of protein. Dietary protein is found in foods such as meat, chicken, fish, egg whites, beans, and whole grains. Once protein is eaten, it is broken down into amino acids, which are nicknamed “the building blocks of protein.”

Amino acids provide the main substance for making the components of the cell, as well as new tissue. Disease-fighting antibodies are also formed from these powerful little amino acids.  Proteins are also essential for the process of muscle contraction. When you are moving your body, two structural proteins, known as actin and myosin, slide past each other as the muscle shortens.

Amino acids are also necessary for the formation of muscle tissue. I have always found it fascinating that, to build bigger muscles, your body must first break down muscle tissue  (during a process called “catabolism”) and then repair and rebuild muscle (anabolism). Protein is an irreplaceable component of this natural cycle, and is essential for both growth and repair. Serious athletes may require more protein than the average person for this reason.

Now, it gets a little more complicated.  There are two types of amino acids found in protein: essential and nonessential. Nonessential amino acids can be produced by the body. Essential amino acids, on the other hand, must be obtained through your diet.  Here is how I remember the two types of amino acids: it is essential that you eat foods containing essential amino acids.  Proteins that contain the essential amino acids can be found in foods of both plant and animal origins.

Proteins containing reasonable amounts of all the essential amino acids in the correct ratios to allow for tissue growth and repair are known as “complete” proteins. Some of the proteins coming from animal sources, such as poultry, meat, fish, milk, and eggs are considered “complete” proteins for this reason.

Proteins lacking ideal amounts of one or more of the essential amino acids are considered “incomplete” proteins. Vegetable proteins such as dried beans, lentils, peas, nuts, and cereals are classified as incomplete for this reason.

The fact that certain vegetable proteins are considered incomplete does not necessarily mean that there is something better about a specific amino acid from an animal source as compared to the same amino acid from a vegetable source. It simply means that incomplete protein from a single plant source, when eaten by itself, does not contain every one of the essential amino acids.

By eating a wide variety of foods such as grains, legumes, and vegetables, each providing a different quantity and quality of amino acids, it is possible to obtain all of the essential amino acids. The proteins from plant sources provide more nutritional benefits when eaten in certain combinations. Throughout history, there have always been  traditional favorites in most cultures that naturally contain complementary amino acids. For example, beans and rice, a staple in many cultures throughout the world, contain complementary amino acids.

Some good sources of protein from plant sources are nuts and seeds, whole grains such as rice, oats, barley, and whole wheat, and legumes, such as lentils, soybeans, peas, and dried beans. The key word here is “variety."

Infants, children, the elderly, and breast-feeding or pregnant women require more protein than others. Stress, injury, and disease may also increase the body’s protein requirements. Insufficient dietary protein can cause a lack of energy, stunted growth, and increased chance of disease, due to a weakened immune system. Starvation diets can result in a protein deficiency and accompanying loss of muscle tissue.

When you eat a meal that is high in protein, your metabolic rate rises significantly. Since protein is an essential element of metabolism, an inadequate dietary protein intake makes it harder for your body to burn fat.

The proper combination of a relatively high level of complex carbohydrates and moderate amount of protein in your diet produces a slow, steady release of energy. However, as with all foods, if you eat more protein than your body needs, it will eventually be converted to bodyfat. 

Protein is necessary to form lean muscle.  It is important to remember, however, that your amount of lean muscle does not increase if you consume more protein than your body requires for energy. The size of the muscle depends on the physical demands made upon it, rather than the extra amount of protein in the diet.

Consuming excessive amounts of dietary protein can be harmful because the metabolism of large quantities of protein can place a strain on liver and kidney function, contributing to dehydration, electrolyte imbalance, and  actual muscle tissue loss.

In addition, trendy high protein diets often consist of large amounts of red meat, which is high in artery clogging saturated fat and cholesterol. It is not necessary to rely heavily on red meat for your daily protein requirements. Due largely to overconsumption of red meat, the average American consumes twice the amount of protein recommended. Again, the source of your nutrients is equally as important as the percentage.

The skinless white meat of chicken and turkey is a high quality protein that is also a good source of vitamins and minerals. These meats are an excellent source of protein, relatively low in fat, and full of vitamins and minerals. Protein rich fish is the best source of omega-3 fatty acids, which can help prevent the plaque buildup that contributes to cardiovascular disease.

Protein is simply one of the six essential nutrients that are vital for optimal health.   The other five nutrients--carbohydrates, fats, vitamins, minerals, and water—are equally as important.  Protein is not the single “magic bullet” that some marketing specialists would like us to believe. 

Protein is, however, a vital nutrient necessary for all bodily functions, including the formation of muscle tissue, and creating the components of the cell and disease fighting antibodies.  What is truly amazing is how the building blocks of protein join together in an intricate process that makes life as we know it possible. 

The real magic is performed when your incredibly intelligent body takes the high quality, clean protein that you supply it with and creates new living tissue.  This is the truly miraculous power of protein, but then again, every nutrient and every organ and system of your body is miraculous, and each is equally important.  This is the simple beauty of pure life itself.