Zinc, handwashing prevent colds, study finds

It began innocently enough for the Rev. W.F. Hampton.


“It started out as a little cough,” he said, as he sat in an exam room in the Family Medicine Clinic at Georgia Regents Medical Center. From there it went to throat irritations and finally seemed to settle deep into his chest by the time he got to the clinic Monday. The cold came despite his strategy for preventing them.

“I believe in the washing of hands frequently, as much as possible,” Hampton said. “I do believe in
hand sanitizer, especially if I am about to eat.”

A review study found that Hampton is right. The study, published in the Canadian Medical Association Journal, looked at what evidence there was out there for preventing and treating colds, relying mostly on randomized clinical trials as providing the most reliable results. The study found there was evidence that “physical interventions” – handwashing, use of hand sanitizers and disinfecting wipes, does help reduce the risk of infection.

Children who took 10 or 15 milligrams of zinc also had a lower number of colds and were less likely to get colds, the study found, and “there is no biological reason why zinc would work only in children and not adults.” Paradoxically, zinc lozenges seemed to reduce the duration and the severity of colds in adults but had little effect in children, the study found.

“The idea of that zinc is intriguing,” said Dr. Ramon Parrish, an associate professor of family medicine at Georgia Regents University, but parents must be careful not to give too much. The study also warned against administering the zinc intranasally because it did not work and came with risks, including burning and a loss of smell.

The use of probiotics or active cultures like those found in some yogurts also seemed to reduce the risk of the upper respiratory infection typical with colds, the study found. Probiotics are a hot treatment right now, particularly for diarrheal disease and other ailments, Parrish said.

“They work really, really well and the side effects are zero,” he said.

What did not work were some tried and true standards – echinacea, vitamins C and D, gargling and ginseng, the study found. That was no surprise to Parrish.

“There is a lot of stuff that everybody thinks works that doesn’t work, particularly vitamin C and oh my goodness echinacea,” he said. “Echinacea is a very beautiful potted plant. And that’s about all it is good for.”

These kinds of studies are helpful for people to know what works and what not to waste their time on, said Dr. Bo Sherwood, the medical director of University Prompt Care in Evans.

“You need to have the evidence to back up what you’re doing,” he said. His advice? Start on zinc immediately, “orally and not nasally,” he said, do over-the-counter antihistamines and decongestants unless they would complicate a medical condition like high blood pressure and “drink plenty of fluids.”