A strong, well-functioning immune system is one of the key aspects of good health, fighting off disease and infections and allowing you to recover more quickly if you do become ill. There is no specific food or nutrient that has been clinically proven to “boost” the immune system all on its own, in fact a healthy immune system relies on a variety of foods that provide a natural abundance of vitamins, minerals and phytonutrients (compounds found in plants that have disease-fighting properties); nutrients such as vitamins C, A, D and E, omega fats and minerals zinc, selenium, iron, copper work together to keep your immune functions running smoothly. And it’s not all about food, regular exercise and good sleep habits can improve immune function. Studies show that even something as simple as a daily 30-minute walk, can have a beneficial effect.
The best nutritional strategy for keeping your immune system strong, is to keep your body well-nourished though a diet that provides all the nutrients it needs in adequate amounts. Below we look at a few of the key nutrients to include.
Your body needs vitamin C for the production of collagen needed to build and maintain healthy skin, this is your body’s first line of defence in preventing disease and infection. Vitamin C is also essential for producing white blood cells and antibodies that fight off infections. On top of that it acts as a powerful antioxidant that helps protect cells from free-radical damage caused by exposure to environmental toxins.
While vitamin C has long had a reputation for helping prevent the common cold and many people gulp it down when they feel cold symptoms coming on, clinical studies have shown that these megadoses don’t actually prevent colds. On the other hand, there is some evidence to show that it does help to slightly reduce the duration of a cold, as well as the symptoms.
Rather than relying on supplements, the best way to get enough vitamin C is is to include rich food sources in your diet every day. One large orange or glass of orange juice will meet your daily needs. Plus you’ll benefit from other immune-protective compounds found in these foods.
Other good sources of vitamin C include grapefruit, honeydew and cantaloupe melon, kiwi, mangoes, papayas, raspberries, starfruit, strawberries and tangerines, each of which provide at least 25 to 30 percent of recommended amounts of vitamin C for a day. Vegetables, such as broccoli, spinach, watercress and peppers, are also great sources. Aim for at least five portions of fruits and vegetables a day, including at one or two that are rich in vitamin C.
Vitamin D is important for innate immunity, this is the way the body prevents the entry and spread of pathogens. Vitamin D stimulates the production of powerful substances in our white blood cells and in the cells that line the respiratory tract and so protect the lungs from infection. Our main source of vitamin D is through exposure to sunlight during the summer months, but stores can run low over the winter. This means we are more reliant of food sources of which there are relatively few. Foods naturally high in vitamin D include oily fish, red meat, liver and eggs.
Beta carotene (vitamin A)
Beta carotene is an orange-yellow pigment found in many fruits and vegetables, that are orange, red or yellow in colour, in particular carrots, sweet potatoes, butternut squash, papaya, peaches and mango . Your body converts beta carotene as it’s needed into active vitamin A, a nutrient important for overall good health and optimal immune function. Like vitamin C, beta carotene is also a powerful antioxidant that helps protect cells from the damage of free radicals.
Beta carotene belongs to a large family of compounds called carotenoids that have numerous health and immune benefits. Lutein is found in egg yolks, corn and leafy vegetables, and lycopene in red fruits and vegetables like tomatoes and watermelon. Research shows that carotenoids work together in promoting health and preventing infection.
Vitamin E is especially important for good immune function. Avocados, wheat germ oil, sunflower seeds, almonds and hazelnuts are all excellent sources of vitamin E.
Your body needs an adequate amount of healthy fats to help you absorb vitamin E (and other fat-soluble vitamins) and to maintain good overall health and a healthy immune system. Include foods rich in monounsaturated and polyunsaturated oils like fatty fish, olives, nuts and seeds.
Selenium is essential for a strong immune response and to fight infection. The best food sources of selenium are Brazil nuts, a small handful of 7-8 nuts will meet your daily requirement. Other good sources include seafood: tuna, red snapper, lobster and shrimp, as well as chicken, whole grains, brown rice, eggs, cottage cheese and sunflower seeds.
Zinc is needed to produce and activate some types of white blood cells that help fight infections. Zinc has also been shown to lower the severity and incidence of the common cold. Zinc-rich foods include oysters, crab, beef, dark-meat turkey and beans.
Omega 3 fats
Omega-3 fats have been shown to be beneficial to the immune system and are found in oily fish (salmon, mackerel and sardine), walnuts and flaxseeds.