Clinical nutrition is all too often practiced using the pharmaceutical model, i.e., what drug for what symptom. The business of selling supplements in our offices is usually done by trying to determine what vitamin or mineral supplement can be used to relieve or mask the patient's symptoms.

There are studies to indicate it may work in a certain percentage of cases but, like prescription drugs, not consistently. The truth is that the science of nutrition is the study of food -- what is or is not being ingested, digested, absorbed, transported, utilized, and eliminated. It stands to reason, I believe, that if we use nutrition as an adjunctive therapy, our first question should be, "Does this patient need dietary modification?"

Last month, I listed common symptoms experienced by patients who need dietary modification. This approach to clinical nutrition is seldom used in the healing arts. This is because inexpensive over-the-counter remedies that mask these symptoms can be purchased almost anywhere. I think that if chiropractors are going to use nutrition to effectively compete for health care dollars, a more scientific approach must be found. One that fills the wide gap between store-bought remedies for symptoms and medical treatment for disease.

To prove the point, let's look at the functions of protein in the body and see if we recognize any of our patients who might require dietary modification involving protein. We are looking for either inadequate protein intake or the inability to adequately digest protein, both of which will eventually produce the early warning signs of protein deficiency.

Growth or increase in muscle mass is possible when there is an appropriate mixture of amino acids over and above those needed for maintenance and repair of tissue. In addition, some cells require larger amounts of specific amino acids. For example, hair, skin, and nails require larger amounts of the sulfur-containing amino acids found in animal protein.

About three percent of the body's protein is being turned over every day. For example, the wall of the intestine requires 70 grams of protein a day. Fortunately, the body can reuse amino acids that would otherwise be lost when tissues are broken down. About the only time the body loses protein (other than in kidney dysfunction) is when the amino acids in the intestinal cells are being lost in the stool instead of being recycled. This results in weight loss.

Hormones such as insulin, epinephrine, and thyroxin are proteins. Hemoglobin is a protein as are almost all the factors involved in blood clotting. The photoreceptors in the eye that are responsible for vision are proteins. The neurotransmitters dopamine (alertness chemical) and serotonin (calming chemical) are proteins. During any protein deficiency state, these compounds receive priority over other less important protein functions.

You will recall that the plasma protein molecules (not used as food by the cells) are too large to pass out of the bloodstream into the tissues. Instead, along with electrolytes like sodium they pull fluid from between the cells back into the bloodstream. An early warning sign of protein deficiency then is the accumulation of fluid in the tissues, giving them a soft, spongy, bloated appearance (edema).

Plasma proteins can neutralize both excess acid and alkali in the blood, thus maintaining normal acid-base balance. Loss of this function results in acidosis or alkalosis and is seldom seen other than in emergency situations. But, the early warning signs of acid-alkaline imbalances are identical to those of protein and carbohydrate deficiencies.

Protein deficiency accounts for much of infant mortality among malnourished children because specific antibodies against infection cannot be formed.

Plasma proteins are also responsible for removal of poisonous or toxic compounds from the body. This function is performed primarily by enzymes (protein substances) found in the liver.

Proteins play an essential role in the transportation of nutrients from the intestine across the intestinal wall to the blood, from the blood to the tissues, and across the cell membranes into the cell. Most of the transportation of nutrients to the cells and removal of waste from the cells to the kidneys and lungs is done by plasma proteins.

Some of these proteins are specific to one nutrient such as retinol-binding protein which only carries vitamin A. Some are able to carry more than one substance such as transferrin which transports both iron and manganese. These minerals compete with each other for binding sites to transferrin. Lipoproteins can carry many lipid-related substances such as cholesterol. When there is an inadequate supply of protein, less of these carrier proteins are available and the transportation of nutrients and removal of cellular waste products can become severely impaired.

If your patient is having any of the problems I've discussed, take a look at what is or is not being ingested and if it is being properly digested, absorbed, transported, utilized, and eliminated.

Next time, I will detail the functions of carbohydrates and lipids.