Medical Minutes
Combating the common cold with zinc
There is no significant difference between zinc acetate lozenges and zinc gluconate lozenges regarding their efficacy in shortening the duration of common colds, according to a new meta-analysis. Researchers analyzed data from 7 randomized trials with zinc acetate and zinc gluconate lozenges and found that the duration of colds was shortened on average by 33 percent.
Zinc lozenges appear to influence the common cold through the release of free zinc ions into the oro-pharyngeal region. However, zinc ions can bind tightly to various chemical complexes in such a way that little or no free zinc ions are released. Previously zinc lozenges containing citric acid were shown to be ineffective in treating colds because citric acid binds zinc ions very tightly and no free zinc is released.
Zinc acetate has been proposed as the most ideal salt for zinc lozenges since acetate binds to zinc ions very weakly. Zinc gluconate is another salt that has been frequently used in zinc lozenges. However, gluconate binds the zinc ion more tightly than acetate does. Because of the somewhat stronger binding, zinc gluconate has been proposed to be a less suitable constituent for lozenges. Although the binding difference between zinc acetate and zinc gluconate is a fact, it is not evident whether that causes significant differences when treating the common cold.
Researchers at the University of Helsinki in Finland conducted the analyses. Three trials had used zinc acetate lozenges and found that colds were shortened on average by 40 percent. Four trials had used zinc gluconate lozenges and colds were shortened on average by 28 percent. The 12 percent difference between the average effects of the two kinds of lozenges was explained purely by random variation.
It is still true, there is no cure for the common cold. However, there is strong evidence that zinc lozenges can shorten common cold duration by more than 30 percent. The researchers report that further studies are warranted to determine the optimum dosing.
Regular exercise coupled with adequate vitamin D may help prevent heart attacks
A new study is suggesting a synergistic link between exercise and good vitamin D levels in reducing the risk of heart attacks and strokes. Both exercise and adequate vitamin D have long been implicated in reducing heart disease risks, but now researchers have identified a positive and direct relationship between exercise and vitamin D levels in the blood that suggests exercise may boost vitamin D stores. They found the two factors working together seemed to somehow do more than either factor alone to protect the cardiovascular system.
Researchers at Johns Hopkins University began their study back in 1987 and tracked 10,342 participants. The average age was 54 at the start of the study and 57 percent were women. Over the 19 years of the study, 1,800 adverse cardiac events occurred, including heart attack, stroke or death due to heart disease or stroke.
After adjusting the data for age, sex, race, education, smoking, alcohol use, blood pressure, diabetes, high blood pressure medication, cholesterol levels, statin use and body mass index, the researchers found that those people who met both the recommended activity levels and had vitamin D levels above 20 nanograms per milliliter experienced about a 23 percent less chance of having an adverse cardiovascular event than those people with poor physical activity who were deficient for vitamin D.
On the other hand, people who had adequate exercise but were vitamin D deficient didn’t have a reduced risk of an adverse event. The researchers caution that people who meet the recommended daily amount of 600 to 800 International Units a day and who have adequate levels of vitamin D don’t need to take additional vitamin supplements.
“More isn’t necessarily better once your blood levels are above 20 nanograms per milliliter,” said Dr. Erin Michos, who is with Johns Hopkins University School of Medicine, Baltimore, Maryland.
Aspirin may help lower breast cancer risk
Recently, researchers found that regular use of low-dose aspirin (81 mg) may help lower overall cancer risk in older adults. Now, a new study is showing that it also specifically reduces the risk of breast cancer in women. Researchers in California at the City of Hope found an overall 16 percent lower risk of breast cancer in women who reported using low-dose aspirin at least three times per week.
“We did not by and large find associations with the other pain medications like ibuprofen and acetaminophen,” said lead author Christina Clarke, PhD, who is with the Cancer Prevention Institute of California.
This study differed from other studies that have looked at aspirin and cancer risk because it focused on the dose levels of the aspirin women had taken and tracked the frequency of the use of low-dose aspirin as opposed to regular aspirin. It was also able to look in detail at subtypes of breast cancer.
“We already knew that aspirin is a weak aromatase inhibitor and we treat women with breast cancer with stronger aromatase inhibitors since they reduce the amount of estrogen postmenopausal women have circulating in their blood,” said City of Hope’s Leslie Bernstein, PhD, who is the director of the Division of Biomarkers of Early Detection and Prevention. “We thought that if aspirin can inhibit aromatase, it ought to reduce the likelihood that breast cancer would develop and it could also be an effective way to improve breast cancer patients’ prognosis once they no longer take the more potent aromatase inhibitors.”
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at medicalminutes@gmail.com.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute.
