Cold and Flu Prevention
With cold weather knocking on the door, many are concerned about falling victim to colds and flu. Flu vaccine-the most effective way to prevent the flu, according to the Centers for Disease Control and Prevention-remains a controversial subject. First, most flu vaccines still contain thimerosal, a mercury based preservative. Second, because of the unpredictability of flu strains, the available vaccine often doesn't match the strain of flu that hits the population.
But even if the vaccine corresponds with the circulating flu strain, it is not that effective. A recent study found that the overall effectiveness of vaccines against flu-like illness in the elderly was 23 percent when vaccine matching was good, and "not significantly different from no vaccination when matching was poor or unknown." Well-matched vaccine, however, may effectively prevent pneumonia and decrease hospitalization rates due to pneumonia or flu.
Recent research shows that the best protection from flu may be flu itself. In the past 20 years, deaths from flu in the elderly have decreased. At the same time, flu vaccination has increased by 45 to 50%. Researchers concluded, that flu vaccine didn't help decrease deaths from flu-people simply acquired natural immunity to the emerging strain of flu. Because of this, many are looking into natural ways to prevent viruses.
Garlic has been used as a health food for more than 5,000 years and is touted for its antibiotic properties and effect on general immunity. A recent study found that a group of people treated with an allicin-containing garlic supplement for a period of 12 weeks between November and February had significantly fewer colds than the group that took a placebo (24 colds vs. 65) and recovered faster if infected. In the group treated with the garlic supplement, 24 people came down with the common cold, which lasted for 1.52 days, compared with 65 people in the no treatment group who had colds that lasted 5 days on average. Garlic therapy should be discontinued at least two weeks prior to surgery to prevent excessive bleeding. People on anticoagulants should consult their physicians.
Green and black teas have been studied for their effects on the cardiovascular system and cancer. A recent Harvard study looked at tea's role in boosting the immunity system. Participants who drank five cups of black tea a day for 2 to 4 weeks increased their levels of interferon, an important immune defense hormone- up to 4 times normal levels. Drinking the same amount of coffee for 12 weeks produced no such effects. The researchers suggest that the key was in Ltheanine, a substance in tea that increases immune response in fighting bacteria, infection, viruses and fungi. Excessive doses may cause insomnia, headache, dizziness, and diarrhea.
The role of vitamin C in the prevention and treatment of respiratory infections has been widely researched. Some studies suggest that vitamin C can affect the duration or severity of symptoms. Others have shown no effect on the symptoms, but suggested that vitamin C can reduce susceptibility to colds. A recent study compared 29 clinical trials in which participants received 200 mg or more of vitamin C daily. The researchers found that vitamin C prevented flu or colds in people who were exposed to "brief periods of severe physical exercise and/or cold environments." In those who regularly take vitamin C, they concluded that vitamin C plays some role in their defense mechanisms, helping them to recover from their colds faster and reducing the severity of symptoms. People with kidney disease should not use vitamin C.
Echinacea has been widely used to prevent and treat colds. Research on the plant, however, has produced conflicting results. A recent study that focused on 3 preparations from echinacea root found no clinically significant effects on the common cold. The critics of the study believe, however, that the dose of 900 mg per day was too low. Echinacea treatment may lead to minor and uncommon abdominal upset, nausea and dizziness. It may be contraindicated in people with autoimmune conditions or HIV.
Zinc lozenges are another home remedy for fighting winter viruses. Although research on this remedy is conflicting, a recent study on zinc gluconate glycine lozenges in school-aged children showed shorter cold duration and fewer colds with the therapy. Zinc lozenges, however, come in different formulations, and more research is needed to assess their effectiveness. In addition, long-term use of zinc lozenges may lead to problems, including impairing the body's immune responses. Excessive zinc in the diet can lead to copper deficiency and may also decrease the levels of HDL ("good") cholesterol in the blood.
Research indicates that chronic stress may substantially increase the risk of catching cold and stress management reduces the duration of flu and colds. Acupuncture may be effective against preventing and curing the common cold, as well. Many chiropractors have also noticed that chiropractic adjustments have helped prevent or reduce the duration of their patients' colds. Preliminary results of an ongoing chiropractic study show that chiropractic may increase immunoglobulin A levels and that it decreases the levels of glucocorticoid cortisol, a major component of stress.