The Best Foods to Eat to Potentially Boost the Immune System
Over the past several decades, intense interest has emerged in the human immune system. Experts have discovered numerous repercussions of weakened immune system responses, including challenges in combating viral infections (e.g., coronavirus/COVID-19), pathogens, and other foreign substances.
Dietary and lifestyle habits can affect immune health, altering both its innate and adaptive functions. A daily diet consisting of foods with key micronutrients is essential for building and supporting a healthy immune system, as well as boosting immune system responses.
The immune system’s cells include many distinct types of white blood cells that are essential for defending the body against viruses and pathogens.
This article explores the role vitamins and minerals play in immune system health. It will also identify the foods with the highest concentrations of these micronutrients that may help boost the immune system.
Vitamins and Minerals that May Boost the Immune System Responses
Vitamin A (also known as the “anti-inflammatory vitamin”) is a group of unsaturated, nutritional, organic compounds that include retinol, retinal, and retinoic acid. They play a crucial role in the diverse physiological processes of the human body, including the development of the immune system and regulation of cellular and humoral immune responses (i.e., an antibody-mediated response).
Vitamin A also assists in different immunity-related aspects like regeneration of mucosal barriers and strengthening the activity of the white blood cells such as neutrophils, macrophages, lymphocytes, and NK (Natural Killer) cells.
Additionally, vitamin A plays a role in the production and regulation of immunoglobulins (i.e., antibodies) and supports antioxidant processes.
Foods high in vitamin A include beef or lamb liver, liver sausage, cod liver oil, sweet potato, winter squash, kale, collards, turnip greens, carrot, mango, cantaloupe, pink or red grapefruit, and watermelon. Vitamin A is fat-soluble; it is best to consume vegetables and fruits that contain vitamin A with healthy fat (e.g., olive oil, avocado, and so forth).
Vitamin E is a fat-soluble antioxidant that immune system cells need. It is considered one of the most effective natural elements known to influence immune function.
This fat-soluble vitamin has anti-inflammatory properties. that help with the growth and activity of white blood cells like macrophages, NK cells, lymphocytes, and dendritic cells.
Vitamin E also helps with promoting T-cell maturity and plays an essential role in enhancing immunoglobulin (i.e., antibody) levels, antibody responses, interleukin production, and signal transduction between white blood cells.
Vitamin E is essential for immune system health because it defends cell membranes against oxidative damage.
As we age, cell membranes become more prone to oxidative damage. Our immune system’s cells’ ability to protect our body weakens, potentially exposing us to more diseases. Reducing oxidative damage to cell membranes helps maintain the activity of the immune system cells. Therefore, it becomes even more essential to supply our bodies with foods that support immune system health.
One example of a vitamin E-rich, healthy food is the almond. Researchers at the Institute of Food Research in Norwich, England, and the Policlinico Universitario in Italy found that almond skin contains compounds that strengthen white blood cells in a way that allows them to find and destroy viruses. In addition, almonds contain omega-3 essential fatty acids, magnesium, niacin, riboflavin, and potassium.
Other foods high in vitamin E include wheat germ oil, sunflower seeds, peanuts, hazelnut oil, avocados, spinach, Swiss chard, pine nuts, and butternut squash.
Vitamin E in supplement form has provided conflicting information with some experts recommending it, and others advising against it. Vitamin E in supplement form may do more harm than good, especially in moderate to high doses. Consult with a doctor first should you decide to use vitamin E supplements.
Vitamin C, also known as L-ascorbic acid, is an essential micronutrient that must be included in daily nutrition because the human body is unable to make it on its own. It is essential for numerous biochemical and physiological processes in the body and plays a vital role in the immune system response.
Some of its vital functions include:
- regulation of enzymatic and antioxidant processes
- enhancement of white blood cell chemotaxis (i.e., directed movement of a cell)
- phagocytosis (i.e., when a cell engulfs a bacteria or particle)
- microbial killing
Vitamin C is vital for the rapid growth of specialized immune cells (e.g., B and T cells). It may also help reduce tissue damage.
One example of a vitamin C-rich food is the Amla berry or Indian gooseberry. It is the central ingredient in chyawanprash, a centuries-old Ayurvedic immunity booster. Both the fresh and dried berries contain extremely elevated levels of vitamin C, more than most other fruit.
It has a slightly bitter taste, so people sometimes consume it as a juice or jam. It is also available in a supplement/dried powder form.
Other foods high in vitamin C include Barbados ‘acerola’ cherries, Kakadu plums, rose hips, chili peppers, guavas, sweet yellow peppers, Camu Camu, blackcurrants, thyme, parsley, mustard spinach, kale, kiwis, broccoli, brussels sprouts, lemons, lychees, American Persimmons, papayas, strawberries, and oranges.
Zinc is an essential mineral for immune system responses. It has specific processes that enable it to boost the immune system, including assisting with the production and activity of white blood cells like neutrophils, lymphocytes, macrophages, and NK cells.
Zinc is also needed in the production of phagocytosis, intracellular killing, immunoglobulins (i.e., antibodies), interleukins, and cytokines.
This mineral may reduce the symptoms of multiple infections, including the common flu, and recurrent ear infections. It may also reduce upper and lower respiratory tract infections, among others.
Some foods high in zinc include meat, shellfish, oysters, legumes (e.g., chickpeas, lentils, and beans), seeds, nuts, dairy, eggs, and whole grains.
Honorable Mention: Quercetin. Quercetin is a flavonoid found in different plants. It has been studied and recommended for everything from cardiovascular and brain health to allergies. It has potential immune-boosting abilities. Quercetin helps enhance the absorption of zinc into the cells.
Foods high in quercetin include kale, onions, cherry tomatoes, broccoli, apples, citrus fruits, red wine, and herbs like sage and green tea. If taking in supplement form, be mindful it could interfere with some medication.
MountSinai.org cautions that high doses of quercetin could lead to kidney problems and interfere with protein function. It’s also recommended to take breaks when supplementing with quercetin. Consult a doctor.
Vitamin B12 is a water-soluble vitamin that helps turn food into energy. It plays an essential role in the growth of red blood cells and the preservation of normal DNA. They are necessary for maintaining the body’s optimal function.
One study noted that participants with a B12 deficiency also had suppressed NK cell activity and a “significant” reduction of T lymphocytes (T-lymphocytes are referred to as CD8+ in the study). The researchers also acknowledged “these abnormalities could be at least partly restored by methyl-B12 treatment.”
Foods high in B12 include meat (e.g., lamb, beef, and veal livers), clams, sardines, fortified cereal, tuna, fortified nutritional yeast, trout, fortified non-dairy milk, milk and dairy products, and eggs.
Vitamin B12 is primarily found in animal products, so a dietary supplement may be needed for vegans and vegetarians. They should consult with a doctor.
Some individuals struggle to absorb B12 from food because their gastrointestinal tract lacks a protein called intrinsic factor. Intrinsic factor is needed to absorb B12 from food. Many are unaware of this and need to consult with a doctor to confirm if they lack the intrinsic factor.
Vitamin B6, also known as pyridoxine, plays several vital roles within the body, including the immune system response.
A 2006 study showed that critically ill patients who supplemented with 50 or 100 milligrams of B6 saw an improvement in their immune response.
Foods high in vitamin B6 include milk, tuna fish, eggs, turkey, chicken and chicken liver, beef, carrots, fortified cereals, green peas, winter squash, bananas, chickpeas, acorn squash, and butternut squash.
Magnesium is one of the most vital micronutrients the body will ever need. It plays an essential role in the immune system, including the first line of immune response defense (i.e., innate immune system) and the second line (i.e., acquired immune system). It also assists antibodies and white blood cells that respond and bind to other cells.
Foods high in magnesium include pumpkin seeds, kernels, almonds, spinach, avocado, cashews, legumes, tofu, seeds, whole grains, black beans, cooked brown rice, baked potato with skin, and shredded wheat (cereal).
Selenium is a mineral with antioxidant properties required by the body for the maintenance of several functions; the most notable of which is with the production of thyroid hormones in the thyroid gland.
Some studies show that selenium strengthens both cell-mediated and humoral immune responses. Conversely, they also showed that a deficiency of selenium may weaken immune responses to viruses, and pathogens, among other things.
Studies also show that a selenium deficiency can weaken the ability of white blood cells (e.g., neutrophils and macrophages) to kill toxins and other foreign substances; thus, making the body potentially more susceptible to infectious viruses and diseases.
Selenium contains selenoproteins that are needed in the antioxidant enzymes and the thyroid gland; both of which serve vital roles in the maintenance of the immune system.
Another powerful antioxidant, Glutathione, is made in the body but needs selenium for production and maintenance.
Foods high in selenium include fish, turkey, chicken, cottage cheese, eggs, brown rice, sunflower seeds, baked beans, mushrooms, oatmeal, and spinach.
Brazil nuts have some of the highest concentrations of selenium per nut, but Medicalnewstoday.com recommends limiting them to just one per day. One Brazil nut provides the complete, adult daily selenium allowance of 55mcg. The overconsumption of Brazil nuts can lead to selenium toxicity.
It is important to monitor the amount of selenium consumed. As with all other vitamins and minerals, too much of a good thing can be dangerous. Consult with a doctor.
Final Thoughts on Boosting the Immune System
Vitamins and minerals play an essential role in boosting the body’s immune system response; however, a deficiency can comprise the immune system and its ability to fight off diseases, viral infections, and pathogens.
As we age, our immune response declines; therefore, it is even more vital to ensure we consume sufficient levels of these vitamins and minerals. Dietary and lifestyle habits can affect our intake of these micronutrients.
Vitamins and minerals cannot prevent a person from catching viruses, infections, or pathogens; however, they can help the body fight them more effectively. Vitamins and minerals provide the substances needed for the biochemical processes that occur in the immune system.
Health experts and organizations like the American Heart Organization recommend having a well-balanced diet to obtain our vitamins and minerals.
If you decide to use supplements, always follow the recommended dosage. Some vitamins and minerals (e.g., vitamin A, zinc, selenium) can build up in the body to toxic levels and cause more harm than good. Consult with a doctor.
This list does not contain all the foods you need to boost your immune system. You should search for different options and try to include as many as you can into your daily diet. Eating right is not the only way to enhance the immune system response, but it is a start and can defend you and your family from several diseases.
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