Vitamin C is most commonly touted as a flu and cold destroyer, but research has shown that its alphabetical neighbour is in fact the most effective. Researchers at the University of Colorado Denver investigated the effects of vitamin D on illness, and discovered that people with low levels of vitamin D were far more likely to have suffered from a recent cold or case of the flu. Vegetables like spinach and kale are great sources of vitamin D, but for the ultimate boost try salmon.
Recipe idea: It’s hard to go wrong with salmon, but for a tasty healthy dish try chargrilling it with asparagus and lime vinaigrette.
Mushrooms are the perfect winter ingredient; they’re tasty, versatile, and contain two things that will help you ditch the flu. The first is selenium, which boosts the production of cytokines. Cytokines are a protein that act as a kick-start for your immune system, and in a recent study at Tufts University were found to help protect the body against viruses. The second is beta glucan. This miracle fibre makes your body more efficient at identifying and destroying infections before they can turn into full-blown illness.
Recipe idea: Is there any dish more warming in winter than a good stew? The answer is no. Mushrooms go great in a stew with beef and onions.
Onions are extremely high in quercetin, which is a flavonoid that has been found to protect against flu. Interestingly research published in the American Journal of Physiology found that this effect was particularly pronounced after exercise, when those given high amounts of quercetin, had a 63% lower infection risk than those who weren’t given the flavonoid. They also contain allicin and allion; two antimicrobial compounds that both protect against flu.
Recipe idea: No matter what you cook with your onions, make sure you use the outermost rings, where quercetin levels are at their highest.
Antioxidants are great at fighting off the flu. You’ll find antioxidants in most berries, but none more so than blueberries. In a study conducted at the University of Oregon, blueberries came out on top in a test of 446 compounds and their flu-fighting capabilities. That’s mostly because of pterostilbene; a miracle antioxidant that’s as good for your immune system as it is hard to pronounce.
Recipe idea: Fresh blueberries are harder to find during winter, so stock up on some frozen ones as a great snack to eat throughout the day.
It seems your dear old Grandma has been right all along. Chicken soup really does help to prevent and fight the flu, and research has proved it. The findings, published in the American Journal of Therapeutics, show that the carnosine found in chicken soup strengthens the immune system and helps to fight the early stages of flu. However, there is a caveat; you’ll need to start adding chicken soup to your diet as soon as the initial symptoms of flu present themselves to enjoy the full effect, and then keep eating it consistently until you recover from the illness.
Recipe idea: Boost the flu-fighting powers of chicken soup even further by adding vegetables like carrots, celery and mushrooms.