Flu is an infection of the upper respiratory tract with one of the influenza viruses. Common symptoms of flu include fever, sore throat, runny nose, cough, headache, muscle pains and fatigue. The common cold is characterized by similar but milder symptoms and is caused by viruses other than the ones causing flu. Although supplementation with zinc is beneficial for common cold, research yields mixed results regarding the efficacy of this mineral for treating flu symptoms.
Zinc is an essential mineral that is found in every cell and is involved in various reactions between enzymes in the body. For proper function, hormones such as insulin, growth hormone and sex hormones depend on certain nutrients, including zinc. Zinc supports optimal sexual function and the integrity of the skin.
By boosting the immune system, zinc helps to fight infections, including viruses that cause upper respiratory infections, although research as of 2010 is controversial regarding the benefits of zinc for treating flu symptoms, according to the University of Maryland Medical Center.
According to a study conducted by D. Hulisz from School of Medicine, Case Western Reserve University, published in the October 2004 issue "Journal of American Pharmacist Association," zinc helps reduce the duration and severity of symptoms of the common cold. The study evaluated the efficacy of zinc used within 24 hours of the onset of the symptoms.
Michael Murray, N.D., author of "The Pill Book Guide to Natural Medicines," suggests that zinc has anti-viral activity against several types of viruses that cause respiratory infections. He also states that based on clinical research, zinc supplement is more effective if is does not contain sorbitol, mannitol or citric acid.
Use lozenges that contain zinc acetate, zinc gluconate or zinc gluconate-glycine. For optimal benefit, treatment with zinc lozenges should start at the first symptoms of the cold or flu.
Safety and Interactions
Zinc supplements should not be taken on empty stomach, since they may cause gastric irritation and nausea. This supplement should not be used in high doses and for more than seven days. Dosages over 90mg per day over a long period of time may depress the immune system and have a negative impact on high-density lipoprotein, or HDL, cholesterol levels. Caffeine and certain medications may interfere with the absorptions of zinc in body.
Consult a qualified practitioner to find out optimal dosage, possible side effects, interactions with conventional drugs or herbs, as well as other minerals and vitamins that should be used in combination with a zinc supplement. Zinc supplements do not replace the standard treatment that may be offered for flu.
- University of Maryland Medical Center: Influenza
- PubMed.gov: Efficacy of zinc against common cold viruses: an overview
- "The Pill Book Guide to Natural Medicines"; Michael Murray, ND; 2002
- Merck Manuals: Influenza