Nutrition and the immune system
Edited by Sobi, Dougie, Eng
Did you know that approximately 60% of our immune system is in our intestinal tract? The gastrointestinal tract is lined with a mucosal layer, which has numerous bacteria living in it. These bacteria are called normal flora. The mucosa along with the normal flora, have a duel job, to prevent absorption of harmful bacteria and viruses, while at the same time, allowing the beneficial nutrients to be absorbed. The foods that are eaten may provide support for this barrier or may cause damage to it.
Poor nutrition may result in increased infections, slow healing from injury and infections, and increase susceptibility to complications from immune system dysfunction.
When people are deficient in nutrients, which is a form of malnutrition, it causes a suppression of the immune system. These nutrient deficiencies can lead to disease and/or death. An example is; during the 1910s through the 1950s, pellagra was a common disease, which is a deficiency in niacin. It was prevalent in the U.S. south and many died within 4 to 5 years from onset. 4 ounces of chicken or tuna a day, or adding lime to corn would have prevented pellagra. 
- 1Eating a well balanced diet where you are consuming all the recommended daily vitamins and nutrient needs can be difficult. Each person has individual tastes, and cost of foods may be a factor making it difficult to obtain a wide variety of fresh foods. Some people take a daily multivitamin and mineral supplements to make up for any potential deficiencies. Taking megadoses of a single vitamin or a multivitamin rarely is needed and has the potential to be harmful.Advertisement
- 2Support a healthy digestive process: The digestive enzymes in your stomach destroy many bacteria and viruses that you ingest with food. Some foods that help to promote a healthy gut are; Pre-biotics & pro-biotics, make sure the cultures are active & live, fermented foods like kimchi, natto, sauerkraut (unpasteurized), chutneys, yogurt, kombucha and cheese. Pre-biotics are carbohydrates that the body cannot be digest. They are food for pro-biotics and are found naturally in foods like whole grains, bananas, garlic, artichokes, onions, and honey. Pro-biotics are live bacteria found in yogurt, pills and fermented foods. They replenish the good bacteria in our guts.Advertisement
- 3Consume protein and fats: Protein aids in building new cells and healing. Fats are needed to aid in absorbing nutrients. There is controversy in regards to what is a healthy fat. 
- 4Healthy balance between omega-3 and omega-6 fatty acids: This appears to be another controversy on what the correct ratio is. In the U.S. the ratio of omega-6 to omega-3 has been greater than 4:1, and in the past, I have read articles that suggested 3:1, 2:1, and 1:1. Did you know that 1/4 cup raw walnuts has 113% of the recommended daily value of omega-3?
- 5Avoid GMO,and non-organic foods: Chemicals can inhibit the functioning of your immune system. By avoiding the consumption of toxins (pesticides/herbicides/fungicides), and avoiding processed foods and eating organic whole grains, organically grown fruits and vegetables, wild-caught fish, meat, poultry and eggs from organically raised animals are ways to minimize the intake of toxins. Read ingredient labels, the more processed an item is, the less nutritious it is. If your great grandmother could not identify the ingredient, you probably don't want to consume it.
- Vitamin A: Vitamin A plays a role in maintaining mucosal surfaces, vision, and cell growth. A deficiency is associated with impaired immunity. Sweet potatoes- 1 medium, carrots- 1 cup, leafy greens-1 cup, all have high Vitamin A content and easily allows you to obtain the daily recommended value.
- Vitamin B2: (
- Vitamin B6: (pyridoxine) Vitamin B6 is required for red blood cell production, metabolism of carbohydrates, production of neurotransmitters and some research has shown vitamin has anti-inflammation effects. 4 ounces of tuna,beef or turkey can give 50% to 70% of daily recommend values. Sweet potatoes have about 33% daily values.
- Vitamin C: Vitamin C is required to produce collagen, for production of neurotransmitters, it enhances the absorption of iron. Papaya has the highest vitamin C, a small papaya giving about 220% of recommended daily value. In addition to broccoli, peppers, leafy greens, strawberries, citrus fruits, 1/2 cup of fresh parsley gives you 50% of daily values. Vitamin C is decreased by heat, oxygen, and storage over time, fresh picked is best with minimal heat if cooked. Steaming 5 minutes or less has the least amount of loss from cooking.
- Vitamin D: The sunshine vitamin. Vitamin D is not really a vitamin, it is a hormone that is produced in the skin from sunlight, it requires cholesterol to metabolize in your body. The recommended daily intake of vitamin D is controversial, there appears to not be agreement on what levels prevent disease and risks. Have your Vitamin D levels checked before starting any supplements.
- Vitamin E: Vitamin E has an ability to help prevent free radical damage, which protects against heart disease. 1/4 cup raw sunflower seeds gives 80% of the recommended daily values. 1/4 cup almonds give 40% of daily values.
- Selenium: Selenium has some anti-inflammation properties and appears to promote immune responses. It is required by the thyroid to regulate properly. Brazil nuts have appear to have the highest selenium content, other foods have very minimal or trace amounts, depending on the soil from which it is grown. Too much selenium can have adverse effects (nerve damage, among others). The Institute of Medicine recommends dietary allowance of selenium at 55 micrograms per day. There is approximately 544 micrograms in an ounce of nuts (depending on the size of the shelled nuts, an ounce is approximately 6 nuts) One Brazil nut every 3 or 4 days should be sufficient for most people. Because it is a food the selenium content will vary from nut to nut.
- Zinc: Zinc is a trace element essential for cells of the immune system, and zinc deficiency affects the ability of T cells and other immune cells to function as they should. 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
- Magnesium: Magnesium is required for metabolism, bone integrity, nerve receptors in inhibiting depression, and enhances control of inflammation. 1/4 cup of raw sunflower seed and 1/4 cup raw pumpkin seeds, each 50% of recommended daily values.