We all get hit with it. A cold, the flu, or just a few days when we’re feeling downright cruddy. Some of us get walloped harder than others, while others seem to avoid sickness the way tweens avoid their parents on social media. Our friend, Dr. Oz, for example, very rarely gets sick, even though he shakes hands with hundreds of people a day; he attributes this to his overall eating approach. (A well-constructed diet done the When Way will fortify your immune system.)
Although we cannot necessarily say that food choices can help make a cough disappear or ease a scratchy throat, we shouldn’t diminish the fact that it can play a role in how you handle the random sicknesses that can get you from time to time.
That, of course, is no surprise. You’ve probably heard (and may even subscribe) to the well-known adage “Feed a cold and starve a fever.” This mama medicine philosophy is pervasive, in part because many people have discovered anecdotally that food can in fact affect how your body prevents and recovers from illnesses like colds and viruses.
What About Vitamin C?
When Dr. C was young, his father insisted that he drink lots of orange juice and take vitamin C tablets if he was sick (or felt like he was about to be). Dr. C—the good boy that he was—obeyed. But as he grew up, he grew skeptical. And he treated vitamin C tablets with the same respect he treated three-hour-old gum—straight to the trash. To this day, Dr. C and his dad cannot agree.
Turns out, the same debate has been raging in scientific journals, newspapers, and households since the 1970s. A few years ago, a comprehensive review of top-level studies examined the issue and found that large doses of vitamin C had no effect on the prevention of colds. However, it had some effect on shortening the symptoms of colds in some people.34 So an apple or orange a day may not keep the doctor away, but eating foods rich in vitamin C is still a good idea because of the long-term effect on your overall health (as well as perhaps playing a role when you do get sick).
As for zinc, a review of studies found that doses of less than 75 milligrams had no effect on cold duration, whereas taking doses of 75 milligrams or more resulted in a 20 to 42 percent reduction in cold duration. Although this may imply zinc looks promising, the safe recommended dose is only 40 milligrams. Taking higher doses of zinc supplements over a long time for an occasional cold carries a risk of significant side effects that range from a metal taste in your mouth to nausea, vomiting—even an increased risk of prostate cancer. The best source of zinc may be our recommended zinc-containing foods like pumpkin seeds, cashews, and beans.35
But is there actually science that links what you eat with these stay-in-bed-and-moan sicknesses?
It’s worth noting that the meals-as-medicine mantra is somewhat flawed in that a cold is an actual illness and a fever is a symptom. It’s sort of like comparing apples to oranges—both of which are fine illness fighters! When you get a cold, you could be suffering from any number of symptoms (cough, congestion, runny nose, loss of appetite, even a fever). A fever itself, though, can be a symptom of any kind of infection that’s causing your immune system to fight whatever bacteria or viruses are invading.
As far as science goes, the data are minimal—and somewhat conflicting. In one study, for example, different immune-boosting benefits were found for both those who were given a nutrient-rich broth and those who refrained from eating.25 A recent study showed that starvation protected mice infected with bacteria and feeding was detrimental—but that the opposite was true when the mice were infected with a virus.26 Alas, the research in humans is as sparse as the supermarket water aisle before a hurricane.
So what’s the bottom line? You should let your body—not a mantra—dictate some of your decision making. Your immune system does need nutrients, so if you’re able to eat—and you feel like eating—you should get some calories in your body (see the following for what kind). But if your symptoms are making you nauseated or you don’t have an appetite, you shouldn’t force it down. No matter what, make sure you’re getting plenty of fluids, because hydration is the key to bouncing back from an illness. You can easily get dehydrated from sweating and producing lots of mucus, and you need to make plenty of urine to clear the waste from your immune system.
MVP: Grandma was right about more than just her philosophy on hugs. She also knew a thing or two about sickness when she pumped you full of chicken soup. Although there aren’t double-blind placebo-controlled studies looking at the effect of chicken soup on curing a cold, some creative studies have been done. In one of the most often cited, from decades ago, scientists found that drinking chicken soup helped with nasal mucus velocity (#bandname).27 Other research has found that ingredients in chicken soup have an anti-inflammatory effect (perhaps because of the chicken, broth, and vegetables all working together).28,29 Bottom line: Chicken soup will help you stay hydrated, which is important, and may have a soothing effect that can both help speed up your recovery and make you feel better, too.
Other Starters: The best part about some of the other foods to prevent sickness is that you can throw them into your soup. Garlic, for example, has been shown to help prevent colds by giving your immune system a kick in the pants.30 And in one experiment, ginger was shown to block viruses.31 Finally, mushrooms (an ancient medicinal remedy) have been shown to help prime immune cells to better fight an infection.32
Cut From the Team: Just because oysters have zinc doesn’t mean they help you shorten a cold’s duration. Zinc lozenges do—but extra zinc can cause big toxicity, so only take it while you have a cold and not year-round.33
| SUB OUT… | SUB IN… |
| Orange juice | An orange. Yes, you want the hydration and nutrients of an orange, but orange juice gives you a high sugar load that just makes bacteria and viruses (and even cancers) feel good about propagating within you. |
| Sushi | Broiled medium salmon or well-cooked ocean trout. When your immune system is busy fighting off an infection, you do not want to test its breadth of action with another potential opponent like something hiding in raw fish. |
| Chia seeds | Unless fully hydrated, chia seeds will suck needed hydration from you. Waterlogged oatmeal may be much better. |