It’s hard for your body to fend off the viruses that cause winter infections like colds and flu if your nutritional status is below par. Most people know that vitamin C-rich foods like citrus fruits become particularly important during the winter months. But did you know that other foods may also support your defences against infection and help relieve the symptoms of colds and flu? Here are five of the most important immune system stimulating foods to include in your diet as the weather gets colder.
Polysaccharide components from the acai berry, a highly nutritious fruit from the Amazon, have recently been shown to exhibit immune-boosting properties, including stimulating the activity of macrophages, immune system cells that support the body’s defences against infection by engulfing pathogens and destroying them.
Additional research is currently underway to determine whether acai berry polysaccharides have the capacity to help the body fight respiratory infections. In addition to these polysaccharides, acai berries contain an abundance of antioxidants, which may provide further support for the body’s immune defences.
Horseradish and wasabi
If you catch a cold, try dosing up on some horseradish or wasabi. The same compounds that give these foods their eye-watering heat also act as decongestants in the nasal passages, clearing out a stuffy nose or blocked sinuses. As an added bonus, they have antimicrobial properties to help your body fight infection.
Carrots, sweet potato and pumpkin
Orange-coloured fruit and vegetables tend to be rich in betacarotene, a nutrient that takes its name from the carrots it’s found in. Once ingested, betacarotene can be converted into vitamin A by your body. Vitamin A plays a key role in immunity, and is particularly important for the health of the mucous membranes of the eyes, nasal passages and lungs, which are sometimes referred to as the immune system’s “first line of defence” against infection. Betacarotene may be particularly important for older people, and may reduce their risk of acute respiratory infections by as much as 30%.
Garlic and onions
Garlic, and its similarly smelly cousins onions, shallots and chives, are renowned for their antimicrobial properties, and many people increase their consumption of these foods during the winter months. That seems to be a wise move, since a study from the UK has shown that people who take garlic supplements during winter suffer from fewer colds than people who take a placebo, and also recover from their colds more quickly and are less likely to experience recurrent infections.
When you’re making soups, stir-fries or casseroles this winter, toss some shiitake mushrooms into the pot. Not only will the rich flavour add depth to your dish, but a compound they contain called lentinan will support your immunity, which may enable you to fight infection more effectively. There’s a good reason these mushrooms have a reputation in Asian countries for helping to promote a long and healthy life!