If you have read my last post you are starting to see that the immune system is dependent on a number of nutrients. The following is intended to elaborate on the last post, in order to provide some of the top food sources of the nutrients previously mentioned. So read up, and eat up!
Squash, such as zucchini or butternut squash, contain Flavonoids, Vitamin A, Vitamin C, and excellent dietary fiber. The darker the color of squash the more flavonoids it contains. Flavonoids support your immune system by working as an antioxidants and anti-inflammatory. Squash is among the top ten sources of Beta-Carotene. Beta-Carotene is of course metabolized by our bodies into Vitamin A, stimulating white blood cells, enhancing resistance to infection, and maintaining proper integrity of skin and mucous membranes. Other food sources of Beta-Carotene include: Carrots, Pumpkins, Sweet Potatoes, Spinach, Kale, Beet Greens, and Cabbage.
The B-Vitamins come from a variety of sources across the food spectrum. Many animal and vegetable foods are excellent sources of B-Vitamins. Firstly these foods should be whole, unprocessed and organic (which is always strongly recommended wherever possible). B-Vitamins are crucial to immune system health because they affect lymphocytes directly as is the case with B-6. This makes the B-Vitamins crucial to white blood cell and antibody integrity. Chief food sources of B-Vitamins include: Turkey, Tuna, Liver, whole grains, bananas, lentils, chilli peppers, beans, mushrooms, berries, nutritional yeast, brewers yeast, and molasses.
Next is the world famous Vitamin C. Highly publicized and widely supplemented with, this essential nutrient cannot be manufactured by the body and thus must be obtained in the diet. Vitamin C is found in high concentrations in immune cells, and stores diminish during infections. It has been hypothesized to modulate the activities of phagocytes, the production of cytokines and lymphocytes. Vitamin C also happens to increase the uptake of many other nutrients and works extremely effectively as an anti-oxidant. Food sources include: rose-hips, gooseberries, papaya, parsley, blackcurrant, red pepper, chilli pepper, sprouts, brussels sprouts, wolf-berry, broccoli, kiwifruit, and citrus fruits (citrus fruits ranking lower than all the other foods mentioned in total Vitamin C content).
A journal from the National Institute of Health suggests that, "Even a marginal vitamin E deficiency impairs the immune response, while supplementation with higher than recommended dietary levels of vitamin E enhances humoral and cell-mediated immunity. The current RDA level of vitamin E prevents clinical deficiency syndrome but in some situations, especially in older subjects or in a disease state, fails to maintain optimal host defense. The immunological parameters reviewed are all sensitive to changes in the availability of vitamin E and, therefore, may reflect the vitamin E status of a given individual more accurately than conventional methods."[Vitamin E status and immune function]. Foods with the highest concentrations of Vitamin E include: Sunflower Seeds, Red Chilli, Paprika, Almonds, Pine Nuts, Basil, Oregano, Green Olives, Spinach.
Zinc is a very important mineral, especially in relation to immune system health. Zinc works to all around maintain the integrity of the immune system throughout the body. It acts as an anti-oxidant, and has been noted to speed up wound healing time. Researchers have hypothesized that zinc could reduce the severity and duration of cold symptoms by directly inhibiting rhinovirus binding and replication in the nasal mucosa and suppressing inflammation [65,66]. Although studies examining the effect of zinc treatment on cold symptoms have had somewhat conflicting results, overall zinc appears to be beneficial under certain circumstances. Several studies are described below in which zinc is administered as a lozenge or zinc-containing syrup that temporarily "sticks" in the mouth and throat. This allows zinc to make contact with the rhinovirus in those areas.
In a randomized, double-blind, placebo-controlled clinical trial, 50 subjects (within 24 hours of developing the common cold) took a zinc acetate lozenge (13.3 mg zinc) or placebo every 2–3 wakeful hours. Compared with placebo, the zinc lozenges significantly reduced the duration of cold symptoms (cough, nasal discharge, and muscle aches) [67]. Some great food sources containing zinc include: Pumpkin Seeds, Dark Chocolate, Garlic, Sesame Seeds, Watermelon Seeds (so buy organic/non-gmo - not seedless), and Chickpeas.
Selenium is another essential component of the immune system. Although its actions can be interpreted as directly improving immune function the anti-oxidant activity is so significant it actually gives the immune system a boost. Unlike most of the other vitamins and minerals mentioned only very little selenium is needed to be enough. Low soil levels of selenium are associated with higher cancer rates (whereas selenium-rich areas have below-average cancer rates, particularly for breast, colon, lung and prostate cancer). Other problems it helps include heart disease, skeletal and muscle problems, growth retardation, reduced immune function, depression, and higher risk of miscarriage. A deficiency of selenium may lead to premature aging. This is because selenium preserves tissue elasticity. Selenium may improve energy levels, prevent and relieve arthritis, slow down the aging process by attacking free radicals and prevent cataracts. Food sources of Selenium include: Brazil Nuts, Sunflower Seeds, Wheat Bran, Rice Bran, Oat Bran, and deep sea ocean fish.
