Zinc is an essential trace mineral with a fair amount of controversy surrounding its medicinal uses. Zinc is the second most common mineral in your body and is found in every cell. Proper zinc levels offer a defense against the entrance of pathogens. In the 1800's, surgeons used zinc as an antiseptic/antibiotic after surgery; they noted its amazing healing properties. Wounds would heal as quickly as 24 hours after an operation, without swelling, and scarring was barely noticeable after a short period of time. Like colloidal silver, liquid zinc is anti-bacterial and anti-viral, but without the potential toxicity issues found with colloidal silver.
Today, supplemental zinc has been found to hinder the progress of macular degeneration, which is an eye disease that affects the part of the retina responsible for central vision. Zinc has also been used with other natural health remedies as it has shown to speed up the healing of stomach ulcers, and help combat zinc deficiencies in those with sickle-cell disease. (1)
The controversial part comes in when you reach the topic of zinc cold remedies. There are two types of zinc-related products to help combat the common cold - lozenges and nasal sprays. In low doses, zinc lozenges have been shown to reduce the time it takes for individuals to get over colds, and also to lessen the severity of cold symptoms.
Zinc nasal sprays, however, get a mixed review. Some studies say that they help shorten the length of cold symptoms, while other studies claim the sprays have no effect. In addition, zinc nasal sprays have been accused of being responsible for users losing some or all of their sense of smell. However, the loss-of-smell issue appears to apply only to zinc gluconate when applied topically (usually sprayed or applied in the nose). It does not include zinc lozenges, tablets, or dietary zinc.
Although zinc nasal sprays get mixed reviews for their effectiveness as a cold remedy, zinc acetate lozenges, as mentioned earlier, come up ahead of the game. A study reported by Reuters in 2008 showed that zinc acetate lozenges shortened the duration of colds in study subjects. Led by Dr. Ananda S. Prasad from Wayne State University School of Medicine, Detroit, the study looked at the impact of the lozenges on 50 volunteers with colds. All of the volunteers had cold symptoms for less than 24 hours before taking part in the study. Among the group who received the lozenges, 56 percent were completely "cold free" within four days, as compared to an average of seven days for the placebo group.
Zinc is present in the food we eat, and it is often not necessary to supplement zinc beyond a normal daily multivitamin. The two best food sources for zinc are shellfish and meat. Oysters are the single best food source for zinc, with more that 70 mg of it per serving.
Meats like crab, lobster, beef and lamb also contain high amounts of zinc. Zinc is not found in large amounts in plant foods, but it is possible for vegetarians to get what they need…barely. The best, common plant sources of zinc are legumes, nuts, seeds, and oatmeal. The amount of zinc present in these foods tends to run about 2 mg per serving. Obviously, it’s much less than found in meat and shellfish; but if you eat enough, it’s enough.
Given the side effects that have been reported for the topical use of zinc, you might do better to avoid the whole mess in the first place and protect yourself by wearing a surgical mask 24/7 and making a point of never shaking anyone's hand or touching any doorknobs or phones. On the other hand, you could just use a powerful immune builder and a good quality natural antipathogenic formula that includes such ingredients as garlic, oil of oregano, olive leaf extract, and yes…liquid zinc, but internally -- not topically.
1 - http://www.umm.edu/altmed/articles/zinc-000344.htm