Zinc Overview, Health Benefits, Source Food, Deficiency, Side Effects

Zinc Overview, Health Benefits, Source Food, Deficiency, Side Effects

Zinc Overview

Zinc, being an important mineral, plays a vital role in protein synthesis and helps regulate the cell production in the immune system of the human body. Zinc is mostly found in the strongest muscles of the body and is found in especially high concentrations in the white and red blood cells, eye retina, skin, liver, kidneys, bones and pancreas. The semen and prostate gland in men also contain significant amounts of zinc.

In the human body, there are more than 300 different enzymes that require zinc to function normally. Researchers believe that 3,000 proteins out of the approximately 100,000 in the body consist predominantly of zinc.

The bio-chemical synthesis of nucleic acids like the RNA and DNA and protein synthesis also seem to be dependent on the presence of zinc as a co-factor. Zinc is essential for normal growth of cells and is needed in the bio-chemical formation of connective tissues - these two processes again rely on the correct functioning of the nucleic acids and normal protein synthesis in cells.

The cells and cellular membranes are also protected by zinc - the mineral may be affecting an antioxidant effect at the cellular level in this case. Changes in the zinc balance in the body is mirrored by changes in the metabolic rate of the other minerals, including copper and magnesium, as well as manganese, and selenium - the metabolism of these minerals responds to the presence of zinc. Zinc may thus be performing a regulatory role with respect to the metabolism of these minerals in the human body.

A normal person contains two to three grams of Zinc at any given time.  There are organs of the human body which secrete Zinc, such as the salivary gland, the prostate gland and the pancreas. Even cells involved in the activity of the immune system secrete zinc. As such, it is used up in various metabolic processes and eliminated through normal excretory and urinary channels, so it needs to be replenished often.

Deficiency Causes and Symptoms of Zinc

Deficiency Causes of Zinc

The status of zinc levels in the human body is affected by many factors which can all contribute to the causative factors behind the deficiency and aggravate the symptoms. The causes bashing the most severe deficiencies of zinc are thought to be the genetic in origin, such as hereditary defects or diseases that can interfere with the proper metabolism of zinc by disrupting the normal biochemical pathways. One example of such a disease is the disorder known as acrodermatitis enteropathica. Reduced blood levels of zinc are also caused by several diseases; this may be due to the increased requirement for the mineral by a body that is weakened with disruptions in the normal biochemical pathways. Among these diseases are included problems like severe alcoholism, conditions such as atherosclerosis and chronic coetaneous ulcers, liver cirrhosis, people affected by Down's syndrome or dwarfism often suffer from deficiencies, as do people affected by lung cancer or leukemia, zinc deficiencies are also evident in those affected by myocardial infarction and pulmonary infection. Zinc deficiencies are also normally seen in individuals affected by tuberculosis, in those suffering from diabetes, those affected by hepatitis, those affected by uremia, those suffering from burns, from bacterial and viral infections and all kinds of acute inflammatory diseases. Zinc deficiencies are also seen in people affected by malabsorption syndromes, by steatorrhea and those who have suffered loss of blood loss, people affected by schizophrenia and thyrotoxicosis may also suffer from zinc deficiency.

Besides deficiency of zinc in foods and disease states, several other factors can affect the levels of zinc in the body. In the average human body, the absorption of the mineral zinc can vary from twenty to eighty percent, but is normally only about twenty to thirty percent in most individuals. A zinc deficiency leads to an increase in the rate of absorption of zinc from the food, this occurs as the body tries to permit more zinc into the blood stream. This effect can also come about based on the content of the diet irrespective of the amount of zinc. The absorption of zinc is also decreased by high fiber diets. The absorption of zinc is also apparently inhibited by the presence of phytates - phosphorus compounds - present in cereal grains. This is the reason for the greater “bio-availability” of zinc sourced from animal foods - these are typically low in fiber and phytates - compared to plant foods. What is not known is the precise amount of zinc absorption inhibited by the fiber found in cereals and vegetables. The absence of any effect from such fibers has been shown in some clinical studies. This factor is no reason to cut off the fiber from the diet, even if the fiber can decrease zinc absorption - plant based fiber is necessary for human health and is comparable to zinc in its usefulness. Zinc absorption in the body is also impaired by lemon juice. Zinc requirements in the body may also be increased by the constant consumption of high protein diets.

Zinc deficiency can also be due to the use of several types of medications, these include chelating agents of all kinds, various diuretics, hormones like the corticosteroids and oral contraceptive pills.

Zinc also prevents toxicity arising from the presence of cadmium in the body. This also depletes the level of zinc as cadmium also uses up zinc if present in the body in high amounts. Zinc requirements tend to increase if the diet is high in cadmium. The cadmium in foods is unfortunately not eliminated during the processing and refining of food products, while the same refinement and processing of foods removes all the zinc. The zinc requirement of the body is thus increased for all individuals mainly relying on a diet of processed foods.

The absorption of zinc from food is dictated by the requirement of the body for the mineral at any particular time. During every meal the human body actually gets two chances to absorb zinc from the food, the first opportunity is from the foods being eaten - if they contain some zinc, the second opportunity is zinc absorbed from the digestive juices secreted in the pancreas. The presence of certain substances in the digestive juices as a matter of fact, greatly enhances the absorption of zinc from the food. The rate of absorption of zinc is also aided by absorption in the intestines and these are not "passive" when it comes to absorption of zinc. The needs of the body can in fact increase or decrease the efficiency of zinc absorption and the rate of intake is dependent on the needs of the body for the mineral at any particular time.

Zinc Deficiency Symptoms

  • Growth retardation
  • Low blood pressure
  • Retarded bone growth
  • Loss of appetite
  • Loss of smell and taste senses
  • Depression
  • Rough skin/Pale Skin
  • Weight loss
  • Diarrhea
  • Hair loss
  • Fatigue
  • White spots under finger nails.
  • Adults may suffer from infertility and impaired sexual functioning where younger males and females suffer from retarded sexual development.
  • Impairment in the healing rate of wounds, severe skin lesions, a persistent loss of appetite.

Marginal deficiencies of zinc seem to affect many more low income pregnant women and pregnant teenagers than it does other people - such people are more susceptible to a deficiency in zinc than others. The outcome of a pregnancy in these groups of people can be improved by supplementing with 25 to 30 mg of zinc daily.

Less than the recommended daily allowance of zinc is found in the average American diet. Such dietary gaps in the intake of zinc can be corrected by the use of a low dose supplement of about 15 mg daily. There is a greater chance of a zinc deficiency affecting long term alcoholics and other individuals suffering from sickle cell anemia. Such a deficiency can also affect those with malabsorption problems and people affected by chronic kidney disease.

Good food sources of Zinc

Seafood is the best natural sources for the mineral zinc - particularly oysters and herring, zinc is also found abundantly in organ meats like the liver, it is also found in good amounts in meats as well as milk, in eggs, in all types of nuts, in all kinds of legumes and in brewer's yeast. Zinc is available in the highest quantities in breast milk - this is the best source of zinc for infants. This is because zinc obtained from breast milk is easily absorbed that it has been used for supplementing the mineral zinc in cases of impaired zinc utilization and malabsorption problems.

Various other compounds also have zinc as a component, and these are available as supplements - compounds like zinc sulfate, zinc gluconate and others are commonly used for supplemental purposes. The most common form of zinc used in medical experiments is zinc sulfate, this is despite the fact that zinc sulfate irritates the stomach. Supplemental zinc in the form of zinc acetate is also commonly used and seems to cause lesser problems than other compound forms of the mineral. Supplements of zinc sulfate can be eaten with the meal to lower the chances of stomach irritations.

Health benefits of Zinc

Health benefits of Zinc: Improve Cardiovascular Health

Zinc is vital to maintain the health of cardiovascular cells and the endothelium. The endothelium is the thin layer of cells that lines the blood vessels and plays a major role in circulation. Low zinc can cause a deficiency in the endothelial barrier, which  leads to high cholesterol buildup and inflammation. Cholesterol and inflammation increase your risk of heart disease.

Studies show that poor zinc status can amplify the negative cardiovascular effects of a high-fat, high-cholesterol diet, whereas an adequate zinc intake will have a protective effect and inhibit the progression of heart disease. The elderly population is especially susceptible to the buildup of inflammatory markers including C-reactive proteins and cytokines, which have been called “slow, silent killers.”

Health benefits of Zinc: Skin Care

Studies have shown zinc to be an effective home remedy for curing pimples and acne. The consumption of antibiotic medication is still considered to be more effective, but the side effects and potential hormonal imbalance that those medicines can cause also must be considered. Also, since one of zinc’s most vital functions is to stimulate white blood cell function. White blood cells are integral in the healing process and can defend the body against a number of infections, including those that commonly attack canker sores, ulcers, burns, surgical incisions, and other various wounds. Zinc is also required for the production of collagen, a connective tissue that is required for skin repair and regrowth.

Health benefits of Zinc: Eczema

Also called “atopic dermatitis”, eczema is an inflammatory and chronic disorder of the skin, and it is mainly caused by deficiency of zinc in the body. Zinc plays an important role in healing chronic infections and assists the body in restoring its ability to heal properly and completely. This irritation can be cleared up by re-balancing the zinc content in your blood.

Health benefits of Zinc: Acne

This mineral is important for eliminating acne from the skin. It regulates and controls the amount of testosterone in the body, which plays a dominant role in causing acne. In addition to that, zinc is also involved in collagen synthesis. This further aids in normalizing the amount of skin oils and improves the maintenance of healthy skin. The open sores that come with acne are practically magnets for bacterial and viral infections, and zinc can stimulate the white blood cell count and reduce the chances of any type of infection. Finally, acne can leave permanent scars on people who suffer from the condition, and zinc can help to reduce the evidence of those scars.

Health benefits of Zinc: Prostate disorder

Zinc is very important in dealing with prostate disorders. Zinc deficiency causes enlargement of the prostate gland and makes it vulnerable to cancer. It is advisable to take 15mg of zinc everyday, under close medical observation, when suffering from prostate disorder. Studies have shown a reduction in tumor growth in the prostate when normal levels of zinc are present in the system.

Health benefits of Zinc: Cognitive Function

Recent research has shown zinc to have a strong impact on mental function, because it can pair up with vitamin B6 to ensure the proper function of neurotransmitters that communicate with the body. Zinc is also found in high concentrations in the hippocampus, which controls thought and memory. For those who have suffered from an injury, extra zinc will keep brain function strong, because the body naturally diverts zinc to the other parts of the body for healing purposes.

Health benefits of Zinc: Support Male Reproductive Health and Fertility

Zinc is a critical mineral for robust testosterone levels, and the cells of the male prostate require a very high concentration of zinc to work optimally. Low zinc in men impairs testosterone production, puts them at risk for developing prostate cancer, and causes infertility. Inadequate zinc has also been linked to low libido.

Health benefits of Zinc: Sense of Smell and Taste

Zinc is one of the most important elements for a healthy life, but it has some very unique benefits as well, including the improvement of the senses of taste and smell. Taste buds and olfactory cells are zinc-reliant, and it is necessary for the proper development and growth of those specific cells. Studies have shown that raising zinc levels can heighten these two senses, because they are finally functioning at optimal levels.

Health benefits of Zinc: Cold

Zinc supplements help in decreasing the severity and duration of colds and other mild illnesses. It reduces the amount of pro-inflammatory cytokines, which aggravate the body during colds or other infections. Also, zinc’s ability to stimulate white blood cell activity makes it ideal for reducing colds and infections.

Health benefits of Zinc: Weight loss

Zinc plays a leading role in weight loss for obese individuals. A number of studies have connected zinc with a decrease in appetite, which prevents overeating. This is related to zinc’s manipulation of the ghrelin hormone, which tells the body when it wants to eat.

Health benefits of Zinc: Pregnancy

Zinc is essential for the repair and functioning of DNA. It is essential for rapid growth of cells and for the building of major constituents of the cell over the course of a pregnancy. So much development and enzymatic activity takes place during pregnancy that zinc is one of the most important nutrients for infants and mothers.

Health benefits of Zinc: Support Female Reproductive Health and Fertility

In women, zinc is involved in the growth process of the oocyte or egg. If women are zinc deficient, the egg won’t mature properly and ovulation will be impeded, causing infertility.
Adequate zinc allows women to use estrogen and progesterone efficiently, supporting reproductive health and ensuring that estrogen does what it’s supposed to do in the body. When estrogen levels become too high, or are inefficiently metabolized they can cause poor reproductive health and breast cancer.

Health benefits of Zinc: Biological Functions

Zinc plays a key role in many biological functions such as reproduction, diabetes control, stress level modulation, immune resistance, smell and taste, physical growth, appetite and digestion.

Health benefits of Zinc: Infection

Zinc helps a person to sense tastes and smells, improves the rate of wound healing, boosts immunity and helps in promoting the fetus growth. Zinc helps in protecting against infectious disorders and fungal infections, which include pneumonia and conjunctivitis.

Health benefits of Zinc: Antioxidant

Zinc acts as an antioxidant and is involved in some of the biochemically decisive reactions in the body, including protein synthesis, enzymatic function and carbohydrate metabolism. Since zinc is involved in so many integral systems and functions of the body, it cannot be stressed enough – You must have zinc in your diet!

Health benefits of Zinc: Enzyme regulation

Zinc is an essential component in a number of enzymes that help in regulating cell growth, protein synthesis, hormonal level, DNA, regulating gene transcription, energy metabolism and other related functions.

Health benefits of Zinc: Cancer

In males, zinc plays a vital role in the prostate gland and prevents premature damage or strain, which can lead to problems like cancer. The natural antioxidant properties of zinc means that it actively seeks out free radicals, the hazardous byproducts of cell metabolism that can cause a number of diseases. Free radicals can morph normal cells into cancerous cells by breaking down the DNA integrity so the elimination of free radicals by antioxidants is one of the most vital lines of defense against many kinds of cancer.

Health benefits of Zinc: Chronic Fatigue

People suffering from chronic fatigue are usually told to consume fish oil, as it is rich in zinc. Many doctors suggest no other medications for curing chronic fatigue except to start consuming fish oil. Zinc must be doing something right. Zinc is integral for normal muscle function, and many researchers believe that muscle fatigue is one of the major causes of chronic fatigue. Therefore, zinc is the ideal supplement to boost your energy levels.

Health benefits of Zinc: Prevent Alzheimer’s & Promote Brain Health

The super antioxidant effects of zinc allow it to effectively help the body eliminate heavy metals from the brain so they don't build up in tissue and cause damage. It also helps maintain cellular homeostasis of brain cells. This combination help prevent neurodegeneration and the development of Alzheimer’s disease. 

Health benefits of Zinc: Alopecia

Alopecia causes loss of hair in both children and adults. Doctors often tell people suffering from this condition to seriously boost their intake of zinc in their diet. Since zinc is so beneficial for hair strength and integrity, the symptoms of alopecia can sometimes be diminished. You can access zinc supplements and capsules in almost all health food stores and groceries. studies have shown that zinc is somewhat more effective on treating childhood alopecia that the conditions of adults.

Health benefits of Zinc: Bone loss

This is a condition  when the bones become weak and fragile. Zinc is a component of hydroxyapatite, which is a salt and makes the bone matrix strong and hard. For this reason, zinc should be added in your dietary plan to avoid bone loss, particularly as you get older, or if you show any signs of premature aging or osteoporosis.

Health benefits of Zinc: Night blindness

Consuming Zinc in quantities of about 150-450 mg will help to improve your vision. Therefore, it is always recommended to consume food like beef, lamb, oysters, buckwheat and crabs as they are rich in zinc content and will improve the ability to see, and is particularly helpful for those suffering from night blindness. Vitamin-A, which is an essential part of improving night vision, stimulates certain enzymes that couldn’t function without zinc, therefore making it a necessary element in reducing night blindness.

Health benefits of Zinc: Improve Sleep, Cognition & Energy Levels

Zinc plays an essential role in neurotransmitter function and helps maintain cognition. It is necessary in the metabolism of melatonin, which is a key hormone for healthy sleep.
In addition, zinc regulates dopamine, an energizing neurotransmitter that gives you drive and focus. Also, zinc is part of an enzyme that is necessary for the anabolism of fatty acids in the brain membrane. This is very important because a key part of supporting brain health and cognition is to ensure the membrane gets the nutrients it needs.

Zinc is a commonly ignored mineral for treating ADHD. Studies show children with ADHD tend to have lower zinc than healthy children. Even more promising, one study of 400 children with diagnosed ADHD found that taking 150 mg/d of zinc sulfate improved impaired social behavior and made subjects less hyperactive and impulsive than a placebo.

Health benefits of Zinc: Elevate Mood and Avoid Depression

The exact relationship between zinc deficiency and depression is unknown, however it surely has to do with the role of zinc in neurotransmitter and hormone production. Dopamine production, which is partly regulated by zinc status, is a chemical that boosts energy, mood, and reward-driven learning.

Zinc Side effects and cautions

Zinc is likely safe for most adults when applied to the skin, or when taken by mouth in amounts not larger than 40 mg daily. Routine zinc supplementation is not recommended without the advice of a healthcare professional. In some people, zinc might cause nausea, vomiting, diarrhea, metallic taste, kidney and stomach damage, and other side effects. Using zinc on broken skin may cause burning, stinging, itching, and tingling.

Zinc is possibly safe when taking by mouth in doses greater than 40 mg daily. There is some concern that taking doses higher than 40 mg daily might decrease how much copper the body absorbs. Decreased copper absorption may cause anemia.

Zinc is unpossibly safe when inhaled through the nose, as it might cause permanent loss of smell. In June 2009, the US Food and Drug Administration (FDA) advised consumers not to use certain zinc-containing nose sprays (Zicam) after receiving over 100 reports of loss of smell. The maker of these zinc-containing nose sprays has also received several hundred reports of loss of smell from people who had used the products. Avoid using nose sprays containing zinc.

Taking high amounts of zinc is likely unsafe. High doses above the recommended amounts might cause fever, coughing, stomach pain, fatigue, and many other problems.

Taking more than 100 mg of supplemental zinc daily or taking supplemental zinc for 10 or more years doubles the risk of developing prostate cancer. There is also concern that taking large amounts of a multivitamin plus a separate zinc supplement increases the chance of dying from prostate cancer.

Taking 450 mg or more of zinc daily can cause problems with blood iron. Single doses of 10-30 grams of zinc can be fatal.

Alcoholism: Long-term, excessive alcohol drinking is linked to poor zinc absorption in the body.

Large doses of zinc can lower blood sugar in people with diabetes. People with diabetes should use zinc products cautiously. 

HIV (human immunodeficiency virus)/AIDS: Use zinc cautiously if you have HIV/AIDS. Zinc use has been linked to shorter survival time in people with HIV/AIDs.

Syndromes in which it is difficult for the body to absorb nutrients: People with malabsorption syndromes may be zinc deficient.

Zinc supplements must be avoided by those affected by Alzheimer's disease according to the evidence garnered from preliminary research. Zinc supplements have more recently been found to lead to an improved mental functioning as demonstrated by preliminary evidence from four patients during a clinical investigation. Someone considers to be the most respected clinical researcher on zinc in the world concluded that the use of zinc does not induce nor exacerbate Alzheimer's disease during a convincing review of the connection between zinc and Alzheimer's disease.

The absorption rate of copper in the body is also inhibited by zinc, this effect of zinc on the absorption of copper can lead to severe anemia and in lower levels of HDL cholesterol - the "good" cholesterol - in the body. When zinc supplements are used for more than a few days, it must be accompanied by an increase in the intake of copper - with the exception of individuals suffering from Wilson's disease. Copper is often included in the formulation of many marketed zinc supplements, this is done to prevent the inhibition of copper by the high doses of zinc.