The goal of cold and flu supplements is to strengthen the immune system to enhance the natural resistance of the body to infections. Supplements taken to fight cold and flu can reduce the duration as well as the severity of the infections.
Cold and Flu Supplements
Vitamin C supplement has been recommended by physicians for more than six decades to alleviate the symptoms of cold and flu. According to the updated report of the Cochrane Database of Systematic Reviews, moderate doses of vitamin C supplements can reduce the risk or severity of cold when a person is exposed to cold environments.
Some studies suggest that vitamin C can reduce the duration of cold by one to two days. About 1 gram of vitamin C in the form of supplement can be taken during the cold and flu seasons. However, mega doses of vitamin C supplements should be avoided. Researchers did not observe any benefit of consuming large amounts of vitamin C supplements in preventing or curing cold and flu. To the contrary, large doses increase the risk of diarrhea.
Zinc is an important immunity booster. It is needed for the normal functioning of the immune system. Zinc supplements are either taken alone or combined with vitamin C supplements for treating cold and flu. After reviewing several studies on the effect of supplements on common cold, researchers reported in the 2012 issue of the Journal of International Medical Research that a combination of 10 mg of zinc and 1 g of vitamin C is more effective in reducing the symptoms of cold than taking vitamin C or zinc separately. Zinc supplements can reduce the risk of upper respiratory infection. However, they may deplete the copper reserve of the body when taken for a prolonged period.
In American folk medicine, Echinacea is widely recommended for fighting cold and flu. However, scientific studies have revealed conflicting results of the effectiveness of Echinacea as a remedy for cold and flu. Some studies suggest that Echinacea supplements can cause up to 30% reduction in the duration and severity of common cold.
However, the herbal supplements cannot prevent viral infections. Most researches that have documented the positive effect of Echinacea have used the Echinacea species Echinacea purpurea in the study. Echinacea supplements work better in adults. Although considered safe for consumption, Echinacea should be avoided by people allergic to flowers belonging to the daisy family and ragweed. It is also not recommended for people suffering from autoimmune disorders such as lupus and rheumatoid arthritis.
Allicin, the active component in garlic, is a powerful immune booster. Several studies have highlighted the effectiveness of garlic in fighting cold and flu.
In a recent study, researchers at the University of Florida have reported in the journal Clinical Nutrition that supplementation with aged garlic causes significant reduction in the symptoms, severity and duration of colds and flu. The compounds in garlic can improve immune cell function, thereby enhancing the natural ability of the body to fight infections.
Several studies have documented the positive effect of the flavonoid sialic acid found in elderberry in fighting common cold and flu viruses.
In a study, published in BMC Complementary and Alternative Medicine, researchers at the Institute for Medical Microbiology at Justus-Liebig University in Germany found that black elderberry extract helps to destroy influenza viruses and human pathogenic bacteria.