The debate rages on about whether it’s better to feed a cold and starve a fever or vice versa. Apparently, though, you don’t want to feed influenza.

"In terms of flu prevention, an apple a day just doesn’t work," says Patrick Crocker, chief of emergency medicine at Dell Children’s Hospital. "Unless you take it with a flu vaccine."

Which is strange, because readers and friends who responded to a Facebook query on flu avoidance tactics often suggested food items.

"Put a cut onion near the bed or in the office … it absorbs airborne viruses," one friend responded.

"Absolutely of no value," Crocker says. "Historically, every epidemic from the early plagues in Europe, people have tried all sorts of things like that, and none of it works."

How about eating fruit?

"It’s not going to have a huge effect in preventing the flu," Crocker says.

One responder suggested brandy. Is that helpful?

"I wish it were," he says, laughing.

Pickle juice?

"Great stuff. No, it doesn’t help a bit … unless you like pickles."

Garlic to boost the immune system?

"I don’t believe there’s any evidence that garlic will help prevent the flu."

Kombucha to detoxify the liver?

"Not going to prevent the flu."

Fermented foods such as miso?

"Sorry."

Crocker also shot down extra doses of vitamin C and other supplements suggested by readers as well as simply willing yourself to stay well.

"Going beyond recommended allowances is not going to prevent the flu," he says, "and positive outlook helps with lots of things, but as a single measure it’s not going to prevent the flu."

One responder claimed that she has never been immunized against the flu. "I’ve just let my immune system build over the years by actually getting the flu!" she wrote.

Crocker said that strategy is dangerous.

"What makes the flu such a hard disease to defend reliably against is the fact that every year it changes its antigenic structure," he explains. "You can get the flu every other — every third year and you’re likely not significantly better protected against this new flu because it changes. So, that’s really not a good idea.

"People tend to forget from year to year that there are a significant number of flu deaths every year and many of them are just tragic — a high school kid comes down with the flu and four days later he’s dead from a secondary pneumonia. There’s no reason to expose yourself to that risk."

But the friends and readers who responded also employ some truly helpful strategies, such as hand-washing.

"Hand-washing is very important," Crocker says. Since flu viruses are spread in little droplets when you cough or sneeze or touch your own runny nose, it’s easy to for them to transmit to surfaces as well as other people. Crocker explains that flu viruses can live for eight hours on those surfaces, allowing plenty of time for them to infect anyone who comes in contact with them and then touches his own face. "A very high percentage of flu cases come from viruses on objects," he adds.

And when you wash your hands, don’t rush through it. Crocker suggests soaping your hands and lathering for 30 seconds before rinsing. "Most people are done in five seconds, and that’s really not adequate to get the virus killed and off your hands."

Responders also touted sleep, exercise and avoiding stress. All are helpful for general health, but none will keep you from getting the flu. "The healthier you maintain your body through a good diet and exercise and activity, the better you weather illnesses," Crocker says. And stress can decrease the effectiveness of the immune system, making you a weaker target for the virus and a good candidate for a rougher case of the flu.

In addition to hand-washing, he recommends drinking plenty of fluids, investing in a humidifier if your home is especially dry, and avoiding those who have already contracted the illness.

You might get the flu anyway. Crocker says the vaccine is not perfect — this year, the protection offered for the Type A strain is maybe only in the 60 percent range — but if you’ve been immunized and get the flu, your case should be milder.

How do you know when a standard case of the flu makes the transition to medical emergency? If you have a fever that lasts for more than four days; you feel sicker than you think is reasonable with the flu; and particularly if you have shortness of breath, trouble breathing or have a cough that suddenly becomes productive of nasty phlegm (it might have blood flecks in it or appear brown or rusty) you need to see a physician, Crocker says.

If you’re a healthy individual older than 2 years and younger than 60, you can probably ride the flu out at home. But to help prevent an epidemic, Crocker suggests that you stay away from public places such as movie theaters, airplanes and grocery stores where you can spread the virus.

If you do have to go out, cover your coughs and sneezes, use hand sanitizer and minimize time spent in busy places. If your child is sick with flu and fever, keep them home from school and make sure they’ve been fever-free for 24 hours before returning.

If you can find a flu shot, it’s not too late to get one. Crocker says we might have 5 to 7 weeks of flu activity left, and it takes the body 2 to 3 weeks to make antibodies and become effective after immunization.