Proteins: Building Blocks of our Cells

Unless we are consuming enough protein, our bodies will not be able to function optimally. For this reason, vegetarians need to be particularly careful that they consume a full range of proteins from non-animal sources. Time and time again, studies have shown that a poor protein intake can have serious consequences on immune function. Eating fish several times a week is an excellent source of protein, as is tofu. Chicken and turkey eaten occasionally are also good sources of protein. Protein is considered one of the most abundant substances found in our bodies and is second only to water. Our skin, muscles, hair, nails, eyes and enzymes are essentially comprised of protein. Unless we supply our bodies with protein, we cannot create infection-fighting antibodies, regenerate our tissues or grow. Protein is chemically composed of carbon, hydrogen oxygen and nitrogen. Its primary function is to build and repair body tissues. Protein molecules are made up of organic compounds called amino acids. These amino acids are linked end to end and create a structure resembling long, sphere-like chains. The individual attributes of each protein are determined by the nature and shape of these amino acid chains. Twenty amino acids are required to synthesize protein and half of these are produced by the human body. Essential amino acids, which must be obtained from the diet include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Arginine and histidine are considered semi-essential.
The most common dietary sources of protein are meat, fish, seafood, eggs, dairy products, grain products, and legumes (which include beans and peas). As we mentioned earlier, as a nation, we consume much more meat than we require. Excess protein consumption can tax the kidneys, contribute to obesity and create colon toxicity. Note: New studies suggest that some people actually need to increase their protein consumption and lower their carbohydrate intake. Remember, it's the type of protein you eat that counts. The properties of specific proteins vary depending on the number and arrangement of individual amino acids. Proteins are classified as being nutritionally complete or incomplete. Complete proteins such as eggs are able to initiate cellular growth. Partially complete protein, such as the gluten found in wheat, contributes to physiological function but is missing specific amino acids necessary to promote growth. Incomplete proteins found in corn, for example, cannot sustain life in and of themselves. However when combined with beans, they form a complete protein.
For our purposes, it is important to learn which foods contain the essential amino acids our bodies cannot produce. Meat and dairy products are the most common sources of essential amino acids in western nations. While plant sources of protein can be lacking in some of these amino acids, mixing certain foods together can create a complete protein food as mentioned in the example of corn and beans. A dietary mix of whole grains and beans can satisfy the body's amino acid needs.

Information provided is intended to provide an electronic reference library about nutrition and health. The views expressed in this or other sections of this site, have not been independently researched or confirmed.
Updated on : 2/19/2012 6:18:52 PM
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