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A zinc supplement can be very helpful for preventing diseases like the flu and pneumonia, as well as for the treatment of these diseases if you already have them.
Overall good nutrition is, of course, key to staying healthy and keeping diseases at bay. Of all vitamins and minerals, however, zinc is highlighted because one of the chief benefits of zinc is its role in improving the body's immune system.
Zinc is well-known for helping people prevent colds and the flu. It has even been found to help Aids patients improve their immunity so that they minimise the symptoms of the disease.
So here are some useful zinc facts about this vital mineral:
Zinc facts #1 - benefits of zinc and deficiency symptoms
Zinc facts #2 - symptoms of zinc deficiency
At the same time, symptoms of zinc deficiency includes:
People most at risk of zinc deficiency include:
Zinc facts #3 - zinc toxicity
Too much zinc, however, can also be harmful and the effects include nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and headaches.
Zinc blocks the absorption of copper, so if you take a zinc supplement, it is important to include some copper. People who should not take zinc supplements include diabetics and those suffering from Alzheimer's disease.
How much zinc is too much? For most adults, the maximum toleraable limit is about 40 mg of zinc per day. For younger people, the limits are roughly as follows: older teenagers (34 mg), young teenagers (23 mg), older children (12 mg) children 1 to 3 years old (7 mg), infants 6 to 12 months (5 mg), infants below 6 months (4 mg).
So make sure you don't overdo your zinc intake. Most multi-vitamin supplements for adults contain about 15mg of zinc, so they are pretty safe.
Zinc facts #4 - foods rich in zinc
Foods rich in zinc: Note also that oysters provide far more zinc than any other foods. A serving of six oysters provide over 70 mg of zinc, which is beyond the limit. Go easy on them.
Among other foods rich in zinc, a small serving of beef provides about 9 mg of zinc. Most other "zinc rich" foods provide only between 0.5 mg and 3.0 mg. So apart from oysters, you need not worry about zinc toxicity from taking foods rich in zinc.
Zinc facts #5 - lozenges against colds and the flu
Depending on the brand, zinc lozenges contain zinc in various forms - zinc gluconate, zinc sulphate and zinc acetate. So far, however, scientists have not been able to find out which form of zinc is more readily absorbed and bioavailable, or whether the body tolerates one form of zinc better than others.
One of the more recent studies was reported in the Annals of Internal Medicine (Aug 15, 2000;133:245-252, 302). In the study, patients with cold symptoms were given either a zinc lonzenge containing 12.8 mg of zinc acetate or a placebo. They were then asked to rate the severity of various symptoms, such as sore throat, runny nose, cough, fever, headache, etc. The study found:
Side effects: The zinc lozenges did produce side effects such as dry mouth and constipation. However, they did not produce signs of zinc toxicity, such as stomach cramps, nausea, vomiting and diarrhea. Still, the reseachers advise that zinc lozenges should be stopped after three days if no improvements in symptoms are felt.
Note about effectiveness: For zinc lozenges to be effective against colds and the flu, they should be sucked and not swallowed. Some doctors who recommend zinc supplements like lozenges also find that taking small amounts frequently is more effective than taking larger amounts infrequently. They might recommend that patients suck, say, 1/4 of a zinc lozenge every 30 to 45 minutes, rather than one zinc lozenge every 2 to 3 hours.
Zinc facts #6 - zinc supplement against pneumonia in elderly
A study led by Dr Simin Nikbin Meydani of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University found that elderly persons who maintain normal serum zinc concentration in the blood have lower risks of developing pneumonia.
Dr Meydani found that nursing home residents with normal serum zinc concentrations in their blood reduced their risk of developing pneumonia by about 50 percent. In addition, deaths from all causes were 39 percent lower. As for those with low levels of zinc, they not only had greater chances of developing pneumonia, but they also required longer treatment with antibiotics before they recovered.
The study, published in the American Journal of Clinical Nutrition (2007: 86: 1167-1173) invovled 617 men and women from 33 nursing homes in the Boston area. All of the participants received daily supplements containing 50 percent of the recommended dietary allowance of several vitamins and minerals, including zinc, for one year.
Zinc facts #7 - zinc helps children recover faster from pneumonia
Researchers from the Johns Hopkins Bloomberg School of Public Health and the International Centre for Diarrhoeal Disease Research, Bangladesh, Centre for Health and Population Research (ICDDR, B) found that children suffering from pneumonia recovered faster when they were given a zinc supplement.
Apart from faster recovery, the researchers note that zinc supplement also helps children avoid being exposed to multiple antibiotics. This, in turn, reduces the risks of microorganisms developing into drug-resistant strains.
"Our study shows that adding zinc to the standard antibiotic treatment significantly reduces the recovery time and overall hospital stay of children with severe pneumonia," said lead author W. Abdullah Brooks, an assistant scientist in the Bloomberg School's Department of International Health and a researcher with the ICDDR, B. "The children who received zinc were also less likely to need a change in the antibiotic being used. This could have significant implications for reducing antibiotic-resistant infections by decreasing antibiotic exposure."
Dr. Brooks and his colleagues conducted a double-blinded, placebo-controlled trial with 270 children who were being treated for severe pneumonia at a hospital in Bangladesh. The children, aged 2 months to 23 months, were randomly selected to receive either a 20mg dose of zinc daily or a placebo in addition to the standard antibiotic treatment for pneumonia. Results of the study were published in The Lancet, May 22, 2004.
Zinc facts #8 - benefits of weekly zinc supplements
In a follow-up study, Dr Brooks and colleagues examined whether a weekly zinc supplement, rather than a daily one, would similarly help children with pneumonia. In this study, 809 children were given a 70 mg dose of zinc supplement, while another 812 children were given a placebo, once a week for a year.
The results established the following zinc facts:
As with other treatments, not all studies are conclusive. Thus, there have also been scientific studies that show zinc supplement to have little or no benefits in treating children with pneumonia.
However, there are enough zinc facts regarding flu prevention and pneumonia recovery to warrant serious consideration of this essential mineral. And while there are some possible side effects with excessive zinc intake, these are not as serious as the side effects of flu shots, pneumonia vaccines and antiviral drugs like Tamiflu.