Zinc Lozenge Effectiveness Studied
Jun. 23, 1998
CHICAGO (AP) _ The controversial researcher who started the zinc lozenges craze says a new study indicates they are ineffective against cold symptoms in children and teen-agers.
But the researcher, Dr. Michael L. Macknin of the Cleveland Clinic Foundation, said that the amount of zinc in the lozenges studied may have been too small or the cherry flavoring somehow inactivated the zinc.
The zinc fad began in 1996, when Macknin's study of 100 adults was published in the Annals of Internal Medicine. Cold sufferers who took the lemon-lime lozenges got over their symptoms more quickly.
The pediatrician later made $145,000 on the sale of stock in Quigley Corp., the Doylestown, Pa., maker of Cold-Eeze zinc lozenges.
His latest study was also supported by a grant from Quigley and was published in Wednesday's Journal of the American Medical Association
A total of 249 suburban Cleveland students in grades one through 12 were recruited within 24 hours of developing a cold. Half took 10-milligram zinc lozenges five or six times a day; the other half took placebos.
The sneezing, coughing, headaches and other symptoms were no different between the two groups, and the duration of the illness was the same.
Studies with adults used dosages higher than 10 milligrams, but the strength was reduced for the youngsters.
In an accompanying editorial, a researcher said the lack of any theoretical basis for why zinc might work ``is troublesome and reminiscent of prior attempts to cure the common cold'' with substances such as vitamins C and A.
``The search for the `magic bullet' that will relieve the multitude of symptoms associated with the common cold continues,'' wrote Dr. Anne Gadomski of the Research Institute at Bassett Hospital in Cooperstown, N.Y.
In 10 previous studies among adults, five found that zinc helped relieve symptoms, while the other five showed no effect.