Zinc is often taken as a natural over-the-counter remedy for fighting colds and symptoms of illnesses. When taken for at least five months, zinc may reduce your risk of becoming sick with the common cold, plus supplementing once you already feel sick can speed up the healing process.
Research shows that zinc can interfere with the molecular process that causes mucus and bacteria to build within the nasal passages. Ionic zinc, based on its electrical charge, has the ability to exert an antiviral effect by attaching to receptors in nasal epithelial cells and blocking their effects.
Research conducted by the Medical Education Center of Chandigarh India found that when zinc was administered within 24 hours of onset of cold-related symptoms, the duration of symptoms was significantly reduced compared to the control group that didn’t supplement with zinc. Fewer patients in the zinc group had cold-related symptoms five and seven days after experiencing the first symptoms compared to those who did not take zinc.
Zinc is an effective anti-inflammatory and antioxidant agent, helping fight oxidative stress and decrease the chance for disease development, including as a natural cancer treatment. Especially in elderly patients, zinc benefits include its ability to support support healthy cell division, preventing cancerous cell mutation and stunting tumor growth.
When researchers from the School of Medicine at the University of Michigan studied potential zinc benefits from zinc supplementation on 50 adults, they found that levels of oxidative stress markers were significantly lower in the zinc-supplemented group than in the placebo group. Those with lower zinc levels who didn’t take supplements had higher levels of inflammatory cytokines, higher plasma oxidative stress markers and endothelial cell adhesion molecules. After zinc supplementation, the incidence of illness-related side effects and infections was also significantly lower in the zinc-supplemented group, another example of zinc’s immune-boosting abilities.
Zinc benefits hormonal health and fertility because it plays an important role in hormone production, including increasing testosterone naturally, which has very widespread roles in both men and women. Zinc also impacts female sex hormones and is even involved in the creation and release of eggs within and from the ovaries.
Zinc is needed for the production of estrogen and progesterone in women, which both support reproductive health. Either too high or too low levels of estrogens can cause problems with menstruation, mood swings, early menopause, infertility and possibly even increase the risk for certain cancers.
Zinc is needed to balance most hormones, including insulin, the main hormone involved in the regulation of blood sugar and as a diabetes natural treatment. Zinc benefits blood sugar levels because it binds to insulin so insulin is adequately stored in the pancreas and released when glucose enters the bloodstream.
It also allows for proper utilization of digestive enzymes that are necessary for insulin to bind to cells so glucose is used as fuel for the body, instead of stored as fat.
Zinc is needed to maintain the health of cells within the cardiovascular system, while also lowering inflammation and oxidative stress. The endothelium, the thin layer of cells that lines the blood vessels, partially relies on adequate levels of zinc. Zinc benefits heart health by supporting healthy circulation, since it helps as a natural remedy for high blood pressure and cholesterol levels from clogged or damaged arteries.
Zinc deficiency is related to chronic digestive problems and diarrheal diseases, which has been shown in several studies. Researchers have found that zinc supplementation can be effective in both prophylaxis and as an acute diarrhea remedy.
Studies show that zinc plays an important role in fertility, especially modulating serum testosterone levels in men. Dietary zinc restriction and deficiency in normal young men is associated with a significant decrease in serum testosterone concentrations, which can negatively impact fertility and lower libido. What does zinc do for you sexually? It can potentially improve low sex drive by increasing testosterone levels.
In one study by the Department of Internal Medicine at Wayne University, after 20 weeks of zinc restriction, giving patients zinc supplementation effectively increased serum testosterone in the majority of men.
Zinc also impacts women’s fertility since adequate levels of zinc are needed during the growth process of the female’s eggs, otherwise eggs cannot properly mature and ovulation suffer.
Zinc affects protein synthesis and is required by the body to use amino acids from foods. It’s also involved in the breakdown of carbohydrates from foods, which are one of the main sources of energy for the body. For this reason, deficiency in zinc can cause low energy levels and contribute to adrenal or chronic fatigue, whereas consuming enough zinc benefits ongoing energy and a healthy metabolism.
Supplementing with zinc is shown to reduce the incidence of infection and correlated with lower levels of liver damage. Zinc can help with a liver cleanse to reduce inflammation in the liver, reduces free radical damage, helps with nutrient absorption and allows for proper waste elimination.
Zinc plays a crucial role in cell division and cell growth, so zinc benefits muscle repair and growth by making it possible for the body to heal itself and maintain strength in the muscular and skeletal systems.
Zinc also helps with the release of testosterone, growth hormone and insulin-like growth factor-1 (IGF-1), all of which build muscle mass and a healthy metabolism.
Zinc benefits muscle mass because it helps increase the amount of testosterone the body is able to produce following exercise — especially weight-training and high intensity interval training — because it enhances the conversion rate of androstenedione to testosterone.
What does it do? Zinc is a component of more than 300 enzymes needed to repair wounds, maintain fertility in adults and growth in children, synthesize protein, help cells reproduce, preserve vision, boost immunity, and protect against free radicals, among other functions.
In double-blind trials, zinc lozenges have reduced the duration of colds in adults,1 2 3 but have been ineffective in children.4 The ability of zinc to shorten colds may be due to a direct, localized anti-viral action in the throat. For the alleviation of cold symptoms, lozenges providing 13-25 mg of zinc, in the form of zinc gluconate, zinc gluconate-glycine, or zinc acetate, are used, typically every two hours while awake, but only for several days. The best effect is obtained when lozenges are used at the first sign of a cold.
Lozenges containing zinc gluconate, zinc gluconate-glycine, or zinc acetate have been effective, whereas most other forms of zinc and lozenges flavored with citric acid,5 tartaric acid, sorbitol, or mannitol, have been ineffective.6 Trials using forms other than zinc gluconate, zinc gluconate-glycine, or zinc acetate have failed, as have trials that use insufficient amounts of zinc.7 Therefore, until more is known, people should only use zinc gluconate, zinc gluconate-glycine, or zinc acetate.
Zinc reduces the body’s ability to utilize the essential mineral copper. (For healthy people, this interference is circumvented by supplementing with copper, along with zinc.) The ability to interfere with copper makes zinc an important therapeutic tool for people with Wilson’s diseasea genetic condition that causes copper overload.
Zinc supplementation in children in developing countries is associated with improvements in stunted growth, increased weight gain in underweight children, and substantial reductions in the rates of diarrhea and pneumonia, the two leading causes of death in these settings.8 9 10 Whether such supplementation would help people in better nourished populations remains unclear.
A small, preliminary trial has found zinc sulfate to be effective for contact dermatitis (a skin rash caused by contact with an allergen or irritant).11 Participants with active skin rashes took approximately 23 mg of zinc (in the form of zinc sulfate) three times daily, for one month. 73% of those taking the zinc sulfate had complete resolution of their skin rashes, while the remaining participants had a 50-75% improvement. Further trials are needed to confirm these preliminary findings, however.
Where is it found? Good sources of zinc include oysters, meat, eggs, seafood, black-eyed peas, tofu, and wheat germ.
Zinc may be of benefit relative to the following conditions:
Acne
Acrodermatitis enteropathica
Childhood intelligence (for deficiency)
Common cold/sore throat (as lozenges)
Down’s syndrome
Down’s syndrome
Infertility (male) (for deficiency)
Night blindness (for deficiency)
Wilson’s disease
Wound healing (oral and topical)
Anemia (for thalassemia if deficient)
Anorexia nervosa
Birth defects prevention
Canker sores (for deficiency only)
Celiac disease (for deficiency)
Cold sores (topical)
Common cold (as nasal spray)
Crohn’s disease
Diabetes (preferably for those with a documented deficiency)
Genital herpes
Gingivitis (zinc plus bloodroot toothpaste)
Halitosis (zinc chloride rinse or toothpaste)
Hepatitis C (zinc-L-carnosine)
HIV support
Immune function (for elderly people)
Infection
Liver cirrhosis (for deficiency)
Macular degeneration
Peptic ulcer
Pregnancy support
Rheumatoid arthritis
Sickle cell anemia
Skin ulcers (oral and topical zinc)
Sprains and strains (if deficient)
Tinnitus (for deficiency only)
Amenorrhea
Athletic performance
Benign prostatic hyperplasia (BPH)
Contact dermatitis
Cystic fibrosis
Dermatitis herpetiformis (for deficiency)
Diarrhea
Ear infections (recurrent)
Gastritis
Gestational hypertension
Goiter
Hypoglycemia
Hypothyroidism
Are there any side effects or interactions? Zinc intake in excess of 300 mg per day has been reported to impair immune function.22 Some people report that zinc lozenges lead to stomach ache, nausea, mouth irritation, and a bad taste. One source reports that gastrointestinal upset, metallic taste in the mouth, blood in the urine and lethargy can occur from chronic oral zinc supplementation over 150 mg per day,23 but those claims are unsubstantiated. In topical form, zinc has no known side effects when used as recommended.
Preliminary research had suggested that people with Alzheimer’s disease should avoid zinc supplements.24 More recently, preliminary evidence in four patients actually showed improved mental function with zinc supplementation.25 In a convincing review of zinc/Alzheimer’s disease research, perhaps the most respected zinc researcher in the world concluded that zinc does not cause or exacerbate Alzheimer’s disease symptoms.26
Zinc inhibits copper absorption. Copper deficiency can result in anemia, lower levels of HDL (“good”) cholesterol, or cardiac arrhythmias.27 28 29 Copper intake should be increased if zinc supplementation continues for more than a few days (except for people with Wilson’s disease).30 Some sources recommend a 10:1 ratio of zinc to copper. Evidence suggests that no more that 2 mg of copper per day is needed to prevent zinc-induced copper deficiency. Many zinc supplements include copper in the formulation to prevent zinc-induced copper deficiency. Zinc-induced copper deficiency has been reported to cause reversible anemia and suppression of bone marrow.31
Marginal zinc deficiency may be a contributing factor in some cases of anemia. In a study of women with normocytic anemia (i.e., their red blood cells were of normal size) and low total iron-binding capacity (a blood test often used to assess the cause of anemia), combined iron and zinc supplementation significantly improved the anemia, whereas iron or zinc supplemented alone had only slight effects.32 Supplementation with zinc, or zinc and iron together, has been found to improve vitamin A status among children at high risk for deficiency of the three nutrients.33
Zinc competes for absorption with copper, iron,34 35 calcium,36 and magnesium.37 A multi-mineral supplement will help prevent mineral imbalances that can result from taking high amounts of zinc for extended periods of time.
N-acetyl cysteine (NAC) may increase urinary excretion of zinc.38 Long-term users of NAC may consider adding supplements of zinc and copper.
The body contains 2 to 3 g of zinc (Zn), found mainly in bones, teeth, hair, skin, liver, muscle, leukocytes, and testes. One third of the 100 µg/dL (15.3 µmol/L) of zinc found in plasma is attached loosely to albumin, and about 2/3 is firmly bound to globulins. There are > 100 zinc metalloenzymes, including a large number of nicotinamide adenine dinucleotide (NADH) dehydrogenases, RNA and DNA polymerases, and DNA transcription factors as well as alkaline phosphatase, superoxide dismutase, and carbonic anhydrase. Dietary intake of zinc by healthy adults varies from 6 to 15 mg/day, and absorption is about 20%. Meat, liver, eggs, and seafood (especially oysters) are good sources. The RDA is 0.2 mg/kg/day for adults.
Ingesting zinc in large amounts (200 to 800 mg/day), usually by consuming acidic food or drink from a galvanized container, can cause vomiting and diarrhea. Doses of zinc ranging from 100 to 150 mg/day interfere with copper metabolism and cause hypocupremia, RBC microcytosis, and neutropenia. Metal fume fever, also called brass-founders’ ague or zinc shakes, is an industrial hazard caused by inhaling zinc oxide fumes; it results in neurologic damage.
The addition of zinc to standard antimicrobial treatment may accelerate recovery from pneumonia, say researchers in this week’s issue of THE LANCET.
Pneumonia is a leading cause of mortality and morbidity in children less than five years old. Zinc is reported to prevent pneumonia, and to prevent and treat diarrhoea, and it may boost the body’s immune response to infection.W Abdullah Brooks and colleagues from the International Centre for Diarrhoeal Disease Research, Bangladesh, investigated whether zinc would help children between 2 and 23 months old with severe pneumonia. 270 children were randomly assigned to receive 20 mg zinc per day, or a placebo, in addition to standard hospital antibiotics.Children given zinc recovered from severe pneumonia an average of one day earlier than did those given placebo, and their average stay in hospital was one day shorter. The zinc supplement was safe and well tolerated. Since a course of zinc treatment costs only US$0·15, and one day in the study hospital costs US$25, the potential cost savings are substantial.Dr Brooks comments: “The effects on treatment failure are striking, have significant implications for reduction of antimicrobial resistance by decreasing multiple antibiotic exposures, and could help reduce complications and death in situations where second line drugs are not available.”Lancet 2004; 363: 1683-88 http://www.thelancet.com
12 OCT. 2001, BY MICHAEL COOGAN, NATIONAL INSTITUTES OF HEALTH – NATIONAL EYE INSTITUTE
No Health without ZINC
Michael Martin looks at the benefits of the metal to human well-being
Zinc can combat childhood killers
BBC NEWS
Link to: http://news.bbc.co.uk/hi/english/health/newsid_553000/553977.stm
Zinc and Human Health – Conclusions of the International Conference, Stockholm, June 12-14, 2000
48% of the World Population at Risk of Zinc Deficiency?
Zinc in Animal Feeds Reviewed
The European Union’s Scientific Committee on Animal Nutrition (SCAN) recently published a review of zinc in feeding stuffs. The Committee concludes that zinc is an essential trace element necessary for all animals which has to be provided in feed to ensure that animals cover their requirements. Currently, zinc is authorized in the EU for all species including fish at a level of 250 mg/kg (Directive 70/524/EEC) and the Committee recognizes that this level exceeds the requirement of farmed livestock, fish, dogs and cats. The Committee also says that no particular risk for the environment has been identified as a result of the use of zinc in animal diets at the currently allowed levels.
The Committee recommends that current allowable zinc levels should be reviewed to better reflect animal requirements, to take into account the natural level of zinc present in feeding stuffs and to allow a safety margin – the Committee suggests that a total zinc level of 150 mg/kg of complete feed would appear to be an appropriate maximum for all animals. Nevertheless, the Committee recommends maintaining comparably high levels of zinc and iron so long as copper levels are kept at 175 mg/kg.
The Committee also recommends a separate review of zinc use in feeds for farmed fish, taking into account the different production systems used in Europe; and possible further consideration of zinc levels in the light of ‘the possible evolution of the authorized load of zinc on soil’.
Source: Opinion of the Scientific Committee on Animal Nutrition on the use of zinc in feeding stuffs. Adopted 14 March 2003. European Commission, Health and Consumer Protection Directorate-General. (Copy available from IZA headquarters).
Boosalis, M.G., et al., Impaired Handling of Orally Administered Zinc in Pancreatic Insufficiency. Amer. Jour. Clin. Nut. 37 1983.
Eby, G.A., et al., Reduction in the Duration of Common Colds by Zinc Gluconate Lozenges in a Double-blind Study. Antimicrobial Agents and Chemotherapy 25 1984.
Fahim, M., et al., Zinc Treatment for the Reduction of Hyperplasia of the Prostate, Federation Proceedings 35 1976.
Michaelson, G., et al., Serum Zinc and Retinol Binding-protein in Acne. Brit. Jour. of Dermatology. 96 1977.
Pandley, S.P., et al., Zinc in Rheumatoid Arthritis. Ind. Jour. of Med. Research 81 1985
Ripa, S., Zinc and Immune Function. Minerva-Med. 86 1995.
Russel, R.M., et al., Zinc and the Special Senses. Annals of internal Medicine 99 1983.
Sandstead, H.H., et al., Zinc Nutriture in the Elderly in Relation to Taste Acuity, Immune Response, and Wound Healing. Amer. Jour. Clin. Nut. 36 1982
Simkin, P.A. Treatment of Rheumatoid Arthritis With Oral Zinc Sulphate. Agents and Actions (Supplement) 1981.
Whitehouse, M.W., et al., Zinc Monoglycerolate: A Slow-release Source of Zinc With Anti-arthritis Activity in Rats. Agents and Actions 31 1990.