Role of Zinc in Health, Nutrition, & Preventing Disorders
Zinc and Health
An adult human body contains between 2 to 3 grams of zinc. A lot of researches done in the last 15 years have brought to light zinc’s discreet role in human health. Zinc is required for metabolic activity of more than 200 of the body’s enzymes (substances that regulate the rate at which various chemical reactions inside living organisms happen) and is considered essential for cell divisions and the synthesis of DNA and protein.
Clinical research has shown that zinc is vital for many biological functions such as disease resistance, wound healing, digestion, physical growth, reproduction, diabetes control, improved taste and smell. Zinc is also imperative for proper learning, and task behavioral performance among children.
Research has shown that zinc deprivation causes poor growth and maturation of the cerebellum and impairs the development of brain cells, which may contribute to learning disorders and behavior problems. Other studies have demonstrated that zinc deprivation has a significant impact on cognitive function, resulting in learning impairments and deficits in working visual memory.
Oral intake of ionic zinc compounds has been found beneficial because the body uses most serum zinc ions to stabilize cell membranes and close pores therein. In this way, zinc protects cell membranes from many cytotoxins, including viruses and venoms. Furthermore, zinc ions are nature’s strongest antioxidants, far more effective than vitamin C and vitamin E, and much safer than selenium. For treatments of wounds, burns and venomous bites, therapeutic doses of zinc in highly ionic form appear to be highly effective.
Anorexia, the medical term that means loss of appetite, has been associated with zinc. Zinc activates areas in the brain that receive and process information from taste and smell sensors. Anorexia responds very well to zinc replacement therapy. In patients suffering from mood disorder, a deficiency of zinc is the cause quite often.
Zinc bolsters immunity because it helps the production of cells in the human body’s immune system, which protect against infection. In fact, zinc acts as a critical ingredient to immune cell functions, assisting in cell division and growth. As body’s immunity generally decreases with old age, elderly persons are more susceptible to various diseases. Providing adequate zinc has been shown to help decrease the rate of infectious disease occurrence in elderly people.
If you crave for wrinkle-free, unblemished and a healthy skin, zinc is for you! Zinc stimulates the transport of vitamin A from the liver to the skin, helping to protect and nourish it. Zinc Oxide is an excellent drying agent and astringent. It has been used for years for soothing diaper rash and relieving itching. Being a natural sun-screen, zinc effectively protects chapped lips and skin from the sun’s harmful rays. Sunburn, blisters and gum diseases are well responded whilst treated with zinc.
Zinc Deficiency: Causes and Effects
Zinc enters in our body through food and water. It is therefore essential for the diet to provide an adequate amount of zinc. Its absorption is equal when taken as oxide, carbonate, sulfate or metal, but as sulfide and mixed iron-zinc-manganese oxide, it is excreted practically unaltered.
The potential absorption of organically bound zinc largely depends on the simultaneous presence of organic or inorganic complexing agents. Many factors can affect the utilization of zinc in food or water. Fiber, phytates, copper, cadmium, iron, calcium, and folic acid can affect the absorption of zinc. Although fibers are beneficial, foods high in fiber, that contain phytates, can decrease zinc absorption. Iron and calcium can compete with zinc for absorption by the body.
Increased intake of copper, calcium or folic acid can also reduce the amount of zinc absorbed. There are some conditions that cause increased excretion of zinc from the body making zinc deficiency more likely. People with diabetes, cirrhosis, or alcoholism are prone to increased zinc excretion.
One easily recognized sign of zinc deficiency is white spots on fingernails. In more severe cases, this is sometimes accompanied by lines or bands. Stretch marks may be another sign of zinc deficiency since zinc is vital to keep tissue elastic, and without zinc the skin sags and wrinkles easily. Other signs are dermatitis, loss of appetite, and slow wound healing.
Zinc deficiency can cause inadequacies in any of the functions that zinc is involved with in the body. The well known effects of zinc deficiency are low growth, lethargy, loss of hair, reduced taste, smell, and vision, poor appetite, impaired reproduction, dermatitis, and reduced resistance to infections.
Average Zinc Content (mg/100g)
Fresh Citrus Fruits
Oils & Fats
Dietary Sources of Zinc
The World Health Organization (WHO) has recommended a daily intake of 15 milligrams of zinc for adults. Depending upon the age and sex of the individual, the WHO recommendation varies between 5 to 15 milligrams of zinc per day.
Foods that are rich in zinc include liver, red meat, nuts, mushroom, and pumpkin seeds. Egg, chicken, and cereals have rather low levels of zinc. Citrus fruits, fruit products, green vegetables, potatoes, oils and fats contain the levels of zinc that are considerably lower. The table at the right would give you an idea of zinc content in these common food items.
It needs to be pointed out that food processing affects zinc content. Stripping grains removes their husks, which contain zinc and other nutrients. Freezing or canning of fruits has a similar effect. Cooking can also deplete zinc content in foods. Zinc is most available to the body from meat. In plant-based foods, zinc bioavailability is generally lower. Phytates found in grains and other fiber-rich foods bind zinc and reduce absorption, as can alcohol.
Although most water contains zinc, normal daily consumption (as drinking water, coffee, tea etc.) can provide only a limited amount of zinc. Moreover, coffee and tea can inhibit zinc absorption.
Several approaches have been suggested for improving zinc levels in population at risk. The alternatives include changes in agricultural technique to boost zinc content of common cereals, changes in cooking methods, nutritional education to improve diets, and administrating zinc supplements. Fortification of food with zinc is another option.