People have suffered from the common cold for centuries, and we're still no closer to finding a cure. In fact, the common cold accounts for approximately 40 percent of time taken off work and millions of days of school missed by children each year, according to some estimates. The good news is that seven superfoods are proven to ease sneezing, coughing, aching, stuffy-head and fever, so they double as natural cold cures.
Lots of studies have been done to gauge the effect of zinc on cold symptoms, with varying results. But the most recent systematic review published in The Cochrane Library concludes that supplementing with the mineral—especially within a day of the onset of symptoms—may indeed reduce the severity and duration of the illness. For example, in one double-blind trial, patients who took a zinc lozenge every couple of hours saw symptoms disappear nearly three days sooner than those given a placebo. Toss back a couple oysters; they're the best natural source of zinc. You'll get 74 mg, or about what you'll find in six lozenges, in just three ounces.
Mom was right: chicken soup really can ease a cold. According to a study in American Journal of Therapeutics, chicken soup's medicinal power may be attributed to carnosine, a compound found in chicken breast and real chicken broth, that helps the body's immune system combat flu-like symptoms by inhibiting the release of inflammatory nitric oxide cells. The downside is the soothing benefits end as soon as the soup passes through the digestive tract, so you'll have to hope mom made a large batch.
Another double blind study also suggests that chicken soup has more than just a placebo effect. Researchers looked at how chicken soup affected airflow and nasal mucus among patients who drank cold water, hot water or chicken soup. Both hot fluids helped relieve stuffy noses, but chicken soup did a better job.
More commonly known as kiwifruit, the Chinese Gooseberry—a nickname given to the native Chinese fruit by New Zealanders—is also one of nature's most powerful cold remedies. Research in the British Journal of Nutrition suggests snacking on nutrient-dense kiwifruit can help relieve cold symptoms and even shorten illness. The study took 132 adults and placed half on a daily diet that included four gold kiwifruit, while the other half supplemented their diets with two bananas each day. The kiwi eaters had sore throats resolve three days sooner, and head congestion resolved almost four days sooner compared to the banana group. Researchers attribute the results to micronutrients in gold kiwifruit that significantly enhanced the concentration of immunity-boosting erythrocytes in red blood cells.
What better group to test the effectiveness of a cold remedy than 200 sleep-deprived, stressed-out college kids living in cramped quarters? A study in the British Journal of Nutrition did exactly that. Researchers assessed how a 12-week course of probiotic supplementation affected the duration and severity of cold symptoms among 198 students, as well as the impact of symptoms on their daily lives. The results were impressive: Students who took the "good bacteria" recovered two days faster than the placebo group, had symptoms that were 34 percent less severe and missed half as many school days (15 versus 34 missed by students taking the placebo). Researchers say probiotic microorganisms may help by softening the body's inflammatory response, which you experience as nasty cold symptoms. Yogurt is the most widely available probiotic food. Look for brands with "live and active cultures" and strains from lactobacillus or bifidobacterium species clearly printed on the label.
A handful of almonds is both preventative against and therapeutic for the common cold, but you have to eat them whole. A study in the journal Microbiology Letters found that polyphenols—disease fighting compounds found in the skin of the almond—can increase the sensitivity of white blood cells known as helper T cells, which are involved in fighting of viruses. And, like a natural vaccine of sorts, the immunity boost lingered even after the almonds had been digested in the gut, researchers say. Interestingly, blanched almonds without skins had little effect on the immune system.
Researchers say honey may be the best natural cure for a hacking nighttime cough. A study in the journal Pediatrics found that children who ate 2 teaspoons of honey 30 minutes before bedtime raw reduced frequency and severity of their nighttime coughing and an overall better night's sleep than those who didn't take the honey. And a double-blind study by Iranian researchers found a combination of honey and coffee to be more effective than a steroid medication and a placebo at relieving symptoms among adults who had suffered a persistent cough for 3 weeks.
There's now science to back-up the cold-busting benefits of garlic. In one study published in The Cochrane Library, adults who received a placebo came down with nearly three times as many colds as those who selected a daily garlic supplement. Moreover, the placebo group suffered with colds three times longer, reporting more than three times more sick days than the garlic group. Researchers hypothesize garlic's cold fighting power comes from the compound allicin, which blocks enzymes that play a role in bacterial and viral infections.
Another double-blind study found daily supplementation of aged garlic extract may enhance immune cell function. People who took 2.56 grams daily for 45 days experienced reduced severity of cold symptoms by 20 percent and recovered 61 percent faster than the placebo group. You can find aged garlic extract at most health food or drugstores, and the good news is it's odorless.