Echinacea, vitamin C fight common cold, COPD

A new study in the Annals of Internal Medicine suggests, according to media reports, that echinacea, an alternative medicine widely used to treat the common cold, may not significantly shorten the cold duration.

The study led by Bruce Barrett and colleagues of the University of Wisconsin-Madison School of Medicine and Public Health actually showed that echinacea did shorten the cold duration by about 10 percent or about half a day.

For the study, 719 patients aged 12 to 80 years with new-onset common cold were assigned either no pills, placebo pills, echinacea pills (blinded) or echinacea pills (open label). Echinacea pills were given at doses of 10.2 grams of dried echinacea root for the first 24 hours and then 5.1 grams for each of the next four days.

The researchers examined both the severity twice a day reported by the patients and interleukin-8 levels and neutrophil counts from nasal wash at baseline and two days later.

The mean global severity was 236, 258, 264 and 286 for the blinded echinacea group, the unblinded echinacea group, the blinded placebo group and the no pill placebo respectively. There was a 28-point difference in the global severity between the two blinded groups, suggesting that echinacea provided some benefits.

The mean common cold duration was 6.34 days for the blinded echinacea group, 6.76 days for the unblinded group, 6.87 days for the blinded placebo group and 7.03 days for the no-pill group.

The researchers also found "Median change in interleukin-8 levels and neutrophil counts were also not statistically significant (30 ng/L and 1 cell/high-power field [hpf] in the no-pill group, 39 ng/L and 1 cell/hpf in the blinded placebo group, 58 ng/L and 2 cells/hpf in the blinded echinacea group, and 70 ng/L and 1 cell/hpf in the open-label echinacea group)."

Barrett et al. acknowledged that the study has its limitation - "Higher-than-expected variability limited power to detect small benefits."

Interleukin-8, a chemokine produced by macrophages and other types of cells, is believed to play a role in the pathogenesis of respiratory tract diseases caused by viral infection like common cold.  It is an important mediator of the immune reaction in the innate immune system.

Neutrophil counts is a measure of the number of serum neutrophil granulocytes which are a type of white blood cell that help fight against infection. A low count indicates high risk of infection. A normal absolute neutrophil count should be above 1,500 cells per microliter.

A health observer said that the study was designed such that the results were complicated and he said the study results suggest a well designed trial may provide solid results to demonstrate the efficacy of echinacea in treating the common cold, which has been no cure thus far.

Quite some studies have demonstrated that echinacea helps the common cold and it may also help those whose health condition may be affected by infections.

A recent study showed the alternative medicine helped relieve exacerbations of chronic-obstructive pulmonary disease (copd) induced by upper respiratory tract infections. The results suggest that the herbal remedy may also helped fight upper respiratory tract infections like the common cold.

For the study, F. Isvaniah and colleagues from University of Indonesia and colleagues gave patients ciprofloxacin for seven days and then ether an echinacea tablet, an echinacea tablet along with supplements of vitamin C and zinc and selenium or a placebo once a day for 14 days.

Those who received both echinacea and micronutrients like vitamin C, selenium and zinc experienced significantly less severe and shorter exacerbation episodes after an upper respiratory tract infection such as the common cold, compared with those on the placebo and those on echinacea alone.

The study in the Nov 10, 2010 issue of Journal of clinical Pharmacy and Therapeutics suggests that echinacea when taken along with other micro-nutrients such as vitamin C, selenium and zinc can significantly alleviate exacerbation symptoms caused by an upper respiratory tract infection like the common cold in COPD patients.