An Athlete's Guide to the Immune System

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Nutrition and Immune Function

An area of active research is how the immune system functions as the body ages. Researchers believe that the aging process somehow leads to a reduction of immune response capability, which in turn contributes to more infections, more inflammatory diseases, and more cancer. As life expectancy in developed countries has increased, so too has the incidence of age-related conditions. Coincidentally the elderly tend to eat less and as a result often lack nutrients in their diets. This is an example of how nutrition may indirectly weaken the immune system via diminished nutrient intake.

Scientists have long recognized that people who live in poverty and are malnourished are more vulnerable to infectious diseases. Whether the increased rate of disease is caused by malnutrition's effect on the immune system is not certain. But we can certainly deduce that it is possible.

Malnourishment can happen right here in our own backyards as well, among the more affluent and middle class. Burgers, fries and white flour have the same effect on the body whether you are living in poverty or wealth. They lack the nutrients that make building blocks for a robust and healthy immune system.

Without adequate nutrition, the immune system is clearly deprived of the components needed to generate an effective immune response. Human malnutrition is usually a complex syndrome of multiple nutrient deficiencies.

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Vitamins and Minerals

There is certainly evidence that certain vitamins, minerals, nutrients and good bacteria can support and strengthen certain elements of the immune system. Some of include Vitamin A, E, C, D, Selenium, Zinc, B6, Omega 3 oils and Lactobacillus.

These vitamins and minerals are commonly found in whole foods such as fruits, vegetables, essential fats, lean meats and some dairy products. Taking a daily multivitamin and mineral supplement brings health benefits including supporting the immune system, however getting your nourishment from organic whole foods remains the best option.

Below is a list of vitamins and minerals, as well as top sources of foods where you can find them. Be sure to include a variety of these foods in your daily nutrition plan for immune system boosting.

Selenium: Some studies have suggested that people with low selenium levels are at greater risk of bladder, breast, colon, rectum, lung, and prostate cancers. Dietary selenium is essential for an optimum immune response, although the mechanisms of this requirement are not always fully understood. (Found in; Brazil nuts, sunflower seeds, bran; oat or rice, pork chops, oysters, liver, lobster, shrimp, caviar).

Omega-3 Fatty Acids: Helps produce Series 1 and Series 3 prostaglandins, which are anti-inflammatory agents. Excessive inflammation in cells can lead to asthma, arthritis, osteoporosis and headaches as well as autoimmune disease. (Found in; flaxseeds and green leafy vegetables. The omega-3 derivatives EPA and DHA are found in high fat, cold water fish such as albacore tuna, sardines, Atlantic halibut and salmon, Coho, pink and King salmon, Pacific and Atlantic herring, Atlantic mackerel, and lake trout).

Lactobacillus GG: has been associated with positive effects on the immune system such as increased cytokine, phagocytic activity (the ones that eat the dead cells and bacteria!) and antibody production. Supplementation is a good option. (Culturelle is a good brand)

Vitamin A: Plays a role in infection and maintaining mucosal surfaces by influencing certain subcategories of T cells and B cells and cytokines. Vitamin A deficiency is associated with impaired immunity and increased risk of infectious disease. (Found in: dried apricots, cantaloupe, sweet potato, squash, liver, carrots, lettuce)

Vitamin B6: Several studies have suggested that a vitamin B6 deficiency can depress aspects of the immune response, such as lymphocytes' ability to mature and spin off into various types of T and B cells. Supplementing with moderate doses to address the deficiency restores immune function, but mega doses don't produce additional benefits. (Found in: pork tenderloin, molasses, sesame seeds, hazelnuts, sunflower seeds, garlic, liver, bananas)

Vitamin C: Is especially required for the functioning of the phagocytes and T-lymphocytes. The major role of vitamin C is the protection of the immune cells against free radicals formed during the interaction of the immune cells with harmful microorganisms. (Found in: Oranges, cantaloupe, red peppers, kiwi, papaya, strawberries)

Vitamin D: Triggers and arms the body's T cells, the cells in the body that seek out and destroy any invading bacteria and viruses. Scientists at the University of Copenhagen have discovered that Vitamin D is crucial to activating our immune defences and that without sufficient intake of the vitamin, the killer cells of the immune system—T cells—will not be able to react to and fight off serious infections in the body. (Found in: Shitake mushrooms, salmon, catfish, soymilk, milk, sardines, eggs, "sunshine.")

Vitamin E: Is an antioxidant, meaning it neutralizes harmful free radical molecules in your body that are associated with cell damage. It also bolsters your immune system, allowing you to effectively fight off infections by bacteria or viruses. (Found in: Sunflower, safflower and wheat germ oil, peanuts, hazelnuts and sunflower seeds, kale, spinach and broccoli).

Zinc: A trace element essential for cells of the immune system. Zinc deficiency affects the ability of T cells and other immune cells to function as they should. Deficiency has been shown to impair cellular mediators of innate immunity such as phagocytosis and natural killer cell activity. Caution: while it's important to have sufficient zinc in your diet (15-25 mg per day), too much zinc can inhibit the function of the immune system. (Found in: wheat germ, oysters, beef, pumpkin seeds, squash seeds, watermelon, dark chocolate/cocoa, peanuts, crab).

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