Food, Nutrition and Your Immune System

Yeah, we’ve all done it before…we feel a cold or the flu coming on and start consuming large quantities of orange juice and citrus fruits in the vain hope that exorbitant amounts of vitamin C will fend off the illness or at least lessen its severity and length. However, there is much more to a healthy immune system than just drinking orange juice.

Your immune system is a complex network of cells, organs and chemicals that fight off foreign invaders in the form of microbes, bacteria, pathogens and viruses. As such, no one vitamin, in this case C, can solely support such a complex system.

However, studies have shown that a single nutrient deficiency, in any of the following: zinc, selenium, iron, copper, folic acid, and vitamins A, B6, C, D and E, can compromise the immune system. In other words, a balanced diet is the key to a healthy immune system (along with proper sleep and an active lifestyle).

Your immune system is actually two systems; innate and adaptive or acquired systems. Your innate system is your first line of defense and is always present. It is comprised of your skin, which acts as a shield; mucus that traps foreign microbes entering your airways; stomach acid, which eliminates bad things you ingest; enzymes in your sweat and tears, and your immune system cells, such as white blood cells, which attack foreign cells that enter the blood stream.

Your adaptive or acquired immune system, made up of your spleen, lymph nodes, bone marrow and thymus, reacts to foreign invaders and develops specific immune cells (antibodies) fight off those invaders. It then learns to recognize them should they return in order to dispatch of them more efficiently next time.

Studies have also revealed that good gut health (beneficial microbes that live in our intestines, crudely referred to as our “gut”), also supports a healthy immune system and that a diet rich in processed foods suppresses this system while one rich in prebiotic and probiotic foods supports it.

So you see, these two systems can certainly use our help, in the form of good nutrition, in fending off all these foreign invaders that enter our bodies on a daily basis. Let’s list the nutrients that support a healthy immune system and the healthy foods that contain them.

Zinc: shellfish, legumes, seeds (hemp, pumpkin, and squash), nuts (pine, peanuts, cashews and almonds), dairy, eggs, and whole grains (wheat, quinoa, and oats).

Selenium: Brazil nuts, yellowfin tuna, oysters, lean chicken and pork, tofu, shiitake mushrooms and shrimp.

Iron: shellfish (clams, mussels and oysters), sardines, haddock, salmon, tuna, chicken, turkey, liver (and other organ meats), spinach, and legumes.

Copper: liver and  other organ meats (two birds, one stone), shiitake mushrooms, nuts and seeds (cashews, almonds and sesame seeds), lobster, leafy greens and dark chocolate.

Folic acid: broccoli, Brussels sprouts, peas, chickpeas, kidney beans and fortified breakfast cereals.

Vitamin A: beef liver (three birds…), cod liver oil, sweet potatoes, carrots, black-eyed peas, spinach, mangos, and cantaloupe.

Vitamin B6: milk, ricotta cheese, salmon, tuna, eggs, chicken liver (I sense a trend), spinach and avocados.

Vitamin C: citrus fruits (oranges, lemons, limes), acerola cherries, rose hips, chili peppers, guavas, and blackcurrants.

Vitamin D: Salmon, herrings, sardines, cod liver oil, egg yolks, mushrooms, and fortified foods and drinks (milk, orange juice, cereals, and soymilk).

Vitamin E: wheat germ oil, almonds, sunflower seeds, nuts (hazel, pine, peanuts, Brazil), Atlantic salmon, rainbow trout, mangos, kiwifruit, and turnip greens.

As you can see, there are numerous foods you can consume contain more than one of the above immune system supporting vitamins or minerals,  including: liver, nuts, shiitake mushrooms, salmon, tuna, shellfish, spinach and legumes.

You probably eat some of these items already, so supporting your immune system, especially as you get older, does not require a complete overhaul of your diet. Little tweaks to your diet will do the trick!