Amid colder temperatures, shorter days and the hustle and bustle of winter festivities, the season may also bring along bouts of the cold or flu. Bah, humbug. Here are some food tips to keep your immune system in tip-top shape, keeping you healthy and strong so you can enjoy all the good tidings of the season!

Vitamin D

Studies show that people with the lowest blood levels of Vitamin D have significantly greater incidences of the cold or flu. Other research also suggests that Vitamin D can be just as effective (if not better) than getting a flu shot.

Adequate levels of Vitamin D in the blood stream are essential in order for your body to activate its immune response and defend against invading, disease causing microbes. Essentially, Vitamin D is required to turn on an antimicrobial protein to fight against foreign invaders. Not only does it activate your immune system, it also guards against inflammation, brought upon by the flu. The best way for your body to get Vitamin D is through direct sunlight. Ultraviolet-B helps your body manufacture this in the perfect amount by converting cholesterol in the skin to what is known as Vitamin D3. However, with barely any sunlight during the winter months, it’s important we supplement.

Vitamin D can be found in some fish oils, milk and dairy products, as well as egg yolk. However, food sources don’t supply us with adequate amounts of Vitamin D, which is why it’s best to take a supplement during winter months. Although government guidelines suggest around 200 IU/day, research suggests at least 2,000 IU/day to ensure normal blood levels.

Vitamin C

Vitamin C is a powerful antioxidant that not only helps to get rid of a cold or flu, but is essential in preventing it in the first place. Vitamin C helps to increase the production of antibodies and white blood cells, which are key in fighting infections. In particular, it increases levels of the antibody interferon, that coats cell walls, preventing entry of viruses.

Since your body does not manufacture or store Vitamin C, it’s essential you add it to your daily routine. Fruits and vegetables are excellent sources. Camu Camu berries are one of the highest plant based sources of Vitamin C (which can also be found in supplements). Other excellent sources include goji berries, red bell peppers, strawberries, broccoli, brussels sprouts, kiwi, lychee and parsley.

Probiotics

Eighty per cent of our immune system resides in the gut. In order to keep our immune system strong, we need to keep our intestinal system healthy with probiotics. Probiotics are live micro-organisms classified as GOOD bacteria that help to fight off all the bad bacteria (foreign, disease causing micro-organisms). They also help improve immune function by increasing the number of T-lymphocytes – virus fighting white blood cells, and natural killer cells.

Probiotics are naturally found in fermented foods, such as miso, yogurt, sauerkraut, buttermilk, kimchi, kamboucha and fermented soy sauce. If you are taking a daily probiotic supplement, it’s best to alternate between brands. Since different brands typically carry different strands of active bacteria culture, it’s best to switch it up and ‘confuse’ the bad bacteria in your system!

Beta Glucans

Beta Glucans are polysaccharides that have the ability to ‘activate’ the immune system and help prevent infections. They modulate white blood cells and keep them in a highly prepared state so that they are ready to attack should there be any threat to our immune system.

Beta Glucans can be found in bakers’ yeast, the bran in grains such as oats and barley, as well as mushrooms – in particular, shiitake, maitaki and oyster. Not only do these mushrooms activate the immune system, they are also rich in minerals, vitamins, polyphenols and sterols that also keep our immune system healthy and strong.