Obesity may protect against benign brain tumors.

Sir, We read with great interest the article by Eby [1]. We agree with the author that ionic zinc content of the lozenges may be one of the factors responsible for the beneficial effect in common cold. Some other relevant negative factors include zinc lozenges producing side-effects and compromising the compliance as well as masking, higher than therapeutic dose of zinc being used in some of the trials, etc. [2,3]. First one (side-effects compromising compliance as well as masking) may be responsible for the varied effects in these trials. In the recent review [4], we included 14 double-blind placebocontrolled trials in the analysis of side-effects of zinc formulations (lozenges or syrup). The data was entered into Review Manager 5 for analysis, and odds ratio (OR) with 95% confidence interval (CI) was calculated. P-value < 0.05 was taken as significant. We found that, zinc lozenges are more likely to produce side-effects than syrup formulations. The results were as follows: any side-effect [lozenge, 2.15 (1.36–3.38) (P = 0.001) versus syrup, 1.03 (0.64–1.66) (P = 0.9)]; bad taste [lozenge, 3.24 (2.25–4.67) (P < 0.0001) versus syrup, 1.15 (0.55–2.39) (P = 0.71)]; nausea [lozenge, 2.46 (1.56– 4.89) (P = 0.0001) versus syrup, 1.24 (0.50–3.08) (P = 0.64)]; diarrhoea [lozenge, 2.09 (0.92–4.75) (P = 0.08) versus syrup, 1.34 (0.30–6.09) (P = 0.7)]; dry mouth [lozenge, 1.42 (0.95–2.11) (P = 0.09) versus syrup, 1.13 (0.43–3.01) (P = 0.8)]. To conclude, in addition to analysis of various formulations of zinc, importance should also be given to the side-effect profile, Medical Hypotheses 77 (2011) 308–313