Protein deficiency diseases

Jan 2014  Protein deficiency diseases
Proteins are the major constituents of the body and are required for most of the vital body functions. Deficiency of proteins can cause many health issues and also diseases like kwashiorkor and marasmus.
As there is continuous proteins building as well as degradation in human body for its normal functions, their regular optimal intake is very essential for keeping good health. If our body does not receive enough of it from the diet, the protein in the muscles and tissues in the body is depleted.

Protein deficiency diseases occur in developing countries due to poverty as well as lack of knowledge about their nutritional requirements. In regions devastated by strife, wars, drought, famine, floods and blights, food becomes scarce and protein inadequacy and connected pathological conditions become common.

In developed nations, though protein inadequacy in nutrition is very rare, it does occur in neglected children and seniors. In patients with chronic debility and cachexia requiring prolonged hospitalization, there is maldigestion, malabsorption and inefficient utilization of nutrients. In such cases there can be shortcoming in amino acids intake.

Unique protein deficiency diseases

Protein C deficiency is an inherited debility affecting the production of body's natural anticoagulant. It causes abnormal blood clotting (thrombosis) specially in veins.

Protein S deficiency also affects the production of natural anticoagulant. However the cause can either be genetic or acquired through a shortfall in vitamin K.

Alpha-1 antitrypsin deficiency, one type of protein inadequacy syndrome, causes difficulty in breathing, wheezing, vision problems and weakness.

Mitochondrial trifunctional protein deficiency causes low blood sugar, weakness, cardiac and hepatic problems, wasting of muscles and difficulty in feeding.

Protein deficiency diseases of specific amino acids

Proteins are made up of amino acids. 22 amino acids are found to be present in human tissues. Many of the amino acids can be synthesized by our body. However nine of them are very essential as our body cannot synthesize and we have to get them through our food sources. The chronic inadequacy of any of these essential amino acids can also cause specific abnormal and harmful functioning. Even the non essential amino acids are also required to be supplemented to ensure an optimal available quantity for building proteins.

Some of these essential amino acids and the deleterious effects on health  due to their inadequacy in the food composition is briefly discussed here.


A shortfall of L-histidine in the food source can lead to symptoms like anemia, lowering of  histamine production, lowered zinc absorption, and lowered immune responses.


A dearth of Isoleucine in the protein source can lead to symptoms like headaches, giddiness, weakness, depression, confusion and irritability.


Undersupply of Leucine in the diet shows symptoms similar to hypoglycaemia. Symptoms include headache, giddiness, weakness, lack of mental stability, disorientation, irritability and depression.


Want of Leucine in dietary protein shows symptoms like irritability, dizziness, fatigue, anemia, mood swing, hair loss and stunted growth.


Scarcity of Methionine in diet can lead to reduced synthesis of cysteine, which protects liver cells from destruction. Increased lipid peroxidation, depression, elevated risk of atherosclerosis are some of the effects of dearth in the biological availability of methionine.


Manifestations of phenylalanine inadequacy include confusion, lethargy, lack of energy, fluid retention, depression, skin lesions, decreased alertness, liver damage, memory problems, slow growth and lack of appetite.


Symptoms of threonine inadequacy include irritability, mood swing, impulsiveness and memory problems. Its inadequacy appears to affect the brain functions.


Dietary dearth of tryptophan may lead to low levels of serotonin. Low serotonin levels are associated with depression, anxiety, panic, irritability, mood change, impatience, impulsiveness, inability to concentrate, increase in weight, food cravings, aggressiveness and insomnia.


A shortfall of valine in dietary protein may affect the myelin covering of the nerves. The inability to metabolise leucine, isoleucine, and valine causes Maple syrup urine disease (MSUD). The urine of the persons affected by this disease smells like maple syrup.
Current topic:
Protein deficiency diseases

No comments: