Fruits and vegetables have a lot more to offer the immune system than just their vitamins and minerals. The phytonutrients, antioxidants, fibers, oils and acids in fruits and vegetables, which are responsible for their various flavors and colors, are also responsible for their many health, healing and immune- modulating properties. These bioactive compounds are used by the body to directly combat inflammation and infections and support detoxification and immune cell function through a multitude of mechanisms, many of which have yet to be fully understood.
Oranges and Yellows
Due to their vitamin-C content, citrus fruits such as oranges and lemons have been touted as cure-alls for the cold and flu. Although vitamin C is integral to proper immune function, citrus fruits have a lot more to offer than just one vitamin. Research published in the “Journal of Agricultural and Food Chemistry” confirms that over 8,000 flavonoids have been identified with many coming from citrus. Some of the most well-studied flavonoid compounds in citrus, such as quercetin, rutin, hesperidin, apigenin and tangeretin, have all shown some ability to target immune malfunctions such as excessive inflammation and cancer development.
Compounds in cranberry juice have been shown to be beneficial for the prevention and treatment of urinary tract infections while also decreasing the use of antibiotics in the elderly. Goji berries, also known as wolfberries, are red berries from China that have immune-regulating properties as evidenced by a 2009 study from “Journal of Medicinal Food”, which showed daily consumption of goji juice increased immune cells called lymphocytes and antibodies called immunoglobulin G when compared to a placebo. Lycopene is the most potent antioxidant in tomatoes and the same pigment molecule that gives red bell peppers and watermelon their red color . However, there are also many additional compounds in tomatoes and tomato products that can protect the DNA of immune cells from oxidative damage and therefore promote proper immune function.
Blues and Purples
Exercise benefits the skeletal system and the cardiovascular system, but strenuous exercise increases inflammation and oxidative stress in the body, which can put a strain on the immune system. Blueberries are full of potent antioxidants called anthocyanins, which help to counter exercise-induced stresses on the immune system by increasing anti-inflammatory compounds and natural killer cells – immune cells which help fight infections. Purple grapes are also full of similar anthocyanin antioxidants, and regular consumption of 100-percent grape juice can increase antioxidant status as well as circulating levels of immune cells called gamma delta T cells in the intestines and lungs. The importance of gamma delta T cells is just starting to be fully appreciated as experiments have shown that they act both as a first line of defense against certain pathogens and also link the innate and adaptive branches of the immune system.
Greens and Whites
Cancer is one of the ultimate immune disorders as cancerous cells need to evade multiple immune defenses and checkpoints in order to become malignant and spread. Regular consumption of cruciferous vegetable such as broccoli, cabbage and cauliflower have beneficial effects on several types of cancer through their powerful anticarcinogenic agents such as sulforaphane, isothiocyanates and indoles. Leafy green vegetables such as spinach and kale are rich in vitamin A, vitamins C, chlorophyll, antioxidants and essential fatty acids, which have immunostimulatory and immunoprotective effects while the sulfur-rich molecules in garlic known as allyl compounds work on numerous immune pathways by being antibacterial, antifungal, antiviral and anticarcinogenic.
Regularly eating fresh fruits and vegetables is the natural way to boost your immune system. These great-tasting fruits and vegetables are nature’s way of keeping you healthy. Natural foods that are high in Vitamins A, C, E, B-6, zinc and folic acid are beneficial in supporting the immune system.
It is much more fun to eat your way to health than to take pills or supplements anyway, so here are six great fruits and six great vegetables that are sure to give your immune system the boost it needs this winter.
Kiwi is loaded with Vitamin C despite being very low in calories. Two medium kiwi add only 90 calories to your diet but deliver a whopping 240% of the daily value for Vitamin C. The kiwi will also provide 450 mg of potassium and four grams of dietary fiber. That is a lot of benefit from such a small fruit. Kiwi is great eaten alone, in a fruit medley, or as a topping for yogurt.
Oranges are frequently associated with Vitamin C. One medium-sized orange delivers 130% or the daily value for Vitamin C. An orange also provides 250 mg of potassium yet has only 80 calories. Oranges are great eaten plain or easily juiced to make a nutritious drink.
Grapefruit are also very high in Vitamin C with one-half of a grapefruit containing 100% of the daily value for Vitamin C. Grapefruit are surprisingly low in calories. Half of a grapefruit contains only 60 calories. Grapefruit are often linked with diets and weight loss but are also an excellent citrus fruit for boosting your immune system. Grapefruit are often eaten plain (sometimes with a sweetener added though) and are also easily juiced to make a refreshing, healthy fruit beverage.
Cantaloupe provides a high level of Vitamin C and Vitamin A. Vitamin A supports healthy skin – our first line of defense against illness and infection . Cantaloupe contains 80% of the daily value of Vitamin C and 120% of the daily value of Vitamin A in one-fourth of a melon. This serving size contains only 50 calories.
Strawberries are another Vitamin C storehouse with eight berries delivering an astonishing 160% of daily value for Vitamin C. These strawberries will also provide 170 mg of potassium while only adding 50 calories to your diet. Strawberries are great to eat alone or easily mashed into a sauce to serve as a dessert with biscuits. Strawberries also go well with a fruit salad.
Blueberries are high in Vitamin B, another important immune system booster. Blueberries are easily eaten plain and are also good as a topping for yogurt or cereal.
Spinach may cause many of us to think of Popeye and large muscles, but it also plays an important role in immune function because of its naturally high antioxidants . Spinach can be cooked and eaten with butter and salt or eaten raw as a salad green.
Broccoli is an excellent source of Vitamin C with one stalk containing 220% of the daily value. This one stalk of broccoli also provides 460 mg of potassium, three grams of dietary fiber, and four grams of protein. Broccoli can be eaten raw, boiled, steamed, or served in many other cooked dishes and contains only 45 calories.
Carrots deliver 110% of the daily value for Vitamin A along with 250 mg of potassium and two grams of dietary fiber. The Vitamin A is useful for immune function support as well as skin and eye health. A carrot has only 30 calories. Carrots can be eaten raw, boiled, steamed, or served in soups, stews or casseroles.
Bell peppers are high in Vitamin C with one medium pepper containing 190% of the daily value for Vitamin C. Bell peppers also 220 mg of potassium and two grams of dietary fiber. A bell pepper has only 25 calories. Bell peppers can be eaten raw or cooked with just about anything to spice up the meal.
Cauliflower is also a good source of Vitamin C with 100% of the daily value contained in one-sixth of a cauliflower head. This serving of cauliflower contains only 25 calories yet has 260 mg of potassium and two grams of dietary fiber. Cauliflower may be eaten raw or cooked.
Sweet potatoes contain 120% of the daily value for Vitamin A in one medium-sized potato. This potato also offers 440 mg of potassium and two grams of dietary fiber. Sweet potatoes may be boiled or baked before serving.
These fruits and vegetables provide tasty ways to support your immune system. A variety of green and yellow-orange fruits and vegetables is the natural way to support your immune system or give it the boost that it deserves. Do yourself a favor next time you are at the market and stock up on nature’s immune system boosters. Dabibi Ori-ibim