Certain foods may be helpful for boosting the immune system and preventing colds and the flu. Here’s a look at five types of nutrients that your immune system needs to perform and which foods to find them in.
An essential nutrient, vitamin C acts as an antioxidant. Antioxidants help fight free radicals, a type of unstable molecule known to damage the immune system.1 There’s some evidence that vitamin C may be particularly helpful in boosting the immune systems of people under major stress. To increase your vitamin C intake, add these foods to your diet:
- citrus fruits and juices (such as orange and grapefruit)
- kiwi fruit
- red and green peppers
Like vitamin C, vitamin E is a powerful antioxidant. Research suggests maintaining ample levels of vitamin E is crucial for maintaining a healthy immune system, especially among older people. To get your fill of vitamin E, look to these foods:
- wheat germ oil
- sunflower seeds
- peanut butter
Zinc is an essential mineral involved in the production of certain immune cells. The National Institutes of Health (NIH) caution that even mildly low levels of zinc may impair your immune function.2 Here are some top food sources of zinc:
- baked beans
- raisin bran
How Can I Boost my Immune System Fast?
Another type of antioxidant, carotenoids is a class of pigments found naturally in a number of plants. When consumed, carotenoids are converted into vitamin A (a nutrient that helps regulate the immune system).3 Look to these foods to boost your carotenoids:
Omega-3 Fatty Acids
Omega-3 fatty acids are a type of essential fatty acid known to suppress inflammation and keep the immune system in check.4 Although it’s not known whether omega-3s can help fight off infections (such as the common cold), research suggests that omega-3s can protect against immune system disorders like Crohn’s disease, ulcerative colitis, and rheumatoid arthritis. Try these omega-3-rich foods:
- oily fish (including mackerel, tuna, salmon, sardines, herring, and trout)
How Can I Boost my Immune System Fast?
Taking Supplements to Boost Your Immune System
Although supplements containing high doses of antioxidants and other nutrients found in whole foods are often touted as natural immune-boosters, some research indicates that taking dietary supplements may have limited benefits for the immune system. If you’re still considering taking them, it’s a good idea to consult your healthcare provider first to weigh the pros and cons.
What are The foods that boost the Immune system?
Immune system boosters
Feeding your body certain foods may help keep your immune system strong. If you’re looking for ways to prevent winter colds and the flu, your first step should be a visit to your local grocery store. Plan your meals to include these 15 powerful immune system boosters.
Most people turn to vitamin C after they’ve caught a cold. That’s because it helps build up your immune system. Vitamin C is thought to increase the production of white blood cells. These are key to fighting infections.
Popular citrus fruits include:
Because your body doesn’t produce or store it, you need daily vitamin C for continued health. Almost all citrus fruits are high in vitamin C. With such a variety to choose from, it’s easy to add a squeeze of this vitamin to any meal.
2. Red bell peppers
If you think citrus fruits have the most vitamin C of any fruit or vegetable, think again. Ounce for ounce, red bell peppers contain twice as much vitamin C as citrus. They’re also a rich source of beta carotene. Besides boosting your immune system, vitamin C may help maintain healthy skin. Beta carotene helps keep your eyes and skin healthy.
Broccoli is supercharged with vitamins and minerals. Packed with vitamins A, C, and E, as well as many other antioxidants and fiber, broccoli is one of the healthiest vegetables you can put on your table. The key to keeping its power intact is to cook it as little as possible — or better yet, not at all.
Garlic is found in almost every cuisine in the world. It adds a little zing to food and it’s a must-have for your health. Early civilizations recognized their value in fighting infections. According to the National Center for Complementary and Integrative HealthTrusted Source, garlic may also help lower blood pressure and slow down the hardening of the arteries. Garlic’s immune-boosting properties seem to come from a heavy concentration of sulfur-containing compounds, such as allicin.
Ginger is another ingredient many turns to after getting sick. Ginger may help decrease inflammation, which can help reduce a sore throat and other inflammatory illnesses. Ginger may also help decrease nausea.
While it’s used in many sweet desserts, ginger packs some heat in the form of gingerol, a relative of capsaicin. Ginger may help decrease chronic pain and may possess cholesterol-lowering properties, according to recent animal research trusted Source.
Spinach made our list not just because it’s rich in vitamin C. It’s also packed with numerous antioxidants and beta carotene, which may increase the infection-fighting ability of our immune systems. Similar to broccoli, spinach is healthiest when it’s cooked as little as possible so that it retains its nutrients. However, light cooking enhances its vitamin A and allows other nutrients to be released from oxalic acid.
Look for yogurts that have “live and active cultures” printed on the label, like Greek yogurt. These cultures may stimulate your immune system to help fight diseases. Try to get plain yogurts rather than the kinds that are preflavored and loaded with sugar. You can sweeten plain yogurt yourself with healthy fruits and a drizzle of honey instead.
Yogurt can also be a great source of vitamin D, so try to select brands fortified with vitamin D. Vitamin D helps regulate the immune system and is thought to boost our body’s natural defenses against diseases.
When it comes to preventing and fighting off colds, vitamin E tends to take a backseat to vitamin C. However, vitamin E is key to a healthy immune system. It’s a fat-soluble vitamin, meaning it requires the presence of fat to be absorbed properly. Nuts, such as almonds, are packed with the vitamin and also have healthy fats. A half-cup serving, which is about 46 whole, shelled almonds, provides nearly 100 percent of the recommended daily amount of vitamin E.
You may know turmeric as a key ingredient in many curries. But this bright yellow, bitter spice has also been used for years as an anti-inflammatory in treating both osteoarthritis and rheumatoid arthritis. Also, researchTrusted Source shows that high concentrations of curcumin, which gives turmeric its distinctive color, can help decrease exercise-induced muscle damage.
10. Green tea
Both green and black teas are packed with flavonoids, a type of antioxidant. Where green tea really excels is in its levels of epigallocatechin gallate, or EGCG, another powerful antioxidant. EGCG has been shown to enhance immune function. The fermentation process black tea goes through destroys a lot of the EGCG. Green tea, on the other hand, is steamed and not fermented, so the EGCG is preserved.
Green tea is also a good source of the amino acid L-theanine. L-theanine may aid in the production of germ-fighting compounds in your T-cells.
Papaya is another fruit loaded with vitamin C. You can find 224 percent of the daily recommended amount of vitamin C in a single papaya. Papayas also have a digestive enzyme called papain that has anti-inflammatory effects.
Papayas have decent amounts of potassium, B vitamins, and folate, all of which are beneficial to your overall health.
Like papayas, kiwis are naturally full of a ton of essential nutrients, including folate, potassium, vitamin K, and vitamin C. Vitamin C boosts white blood cells to fight infection, while kiwi’s other nutrients keep the rest of your body functioning properly.
When you’re sick, chicken soup is more than just a feel-good food with a placebo effect. It helps improve symptoms of a cold and also helps protect you from getting sick in the first place. Poultry, such as chicken and turkey, is high in vitamin B-6. About 3 ounces of light turkey or chicken meat contains 40 to 50 percent of your daily recommended amount of B-6.
Vitamin B-6 is an important player in many of the chemical reactions that happen in the body. It’s also vital to the formation of new and healthy red blood cells. Stock or broth made by boiling chicken bones contains gelatin, chondroitin, and other nutrients helpful for gut healing and immunity.
14. Sunflower seeds
Sunflower seeds are full of nutrients, including phosphorous, magnesium, and vitamin B-6. They’re also incredibly high in vitamin E, a powerful antioxidant.
Vitamin E is important in regulating and maintaining immune system function. Other foods with high amounts of vitamin E include avocados and dark leafy greens.
Shellfish isn’t what jumps to mind for many who are trying to boost their immune system, but some types of shellfish are packed with zinc.
Zinc doesn’t get as much attention as many other vitamins and minerals, but our bodies need it so that our immune cells can function as intended.
Varieties of shellfish that are high in zinc include:
Keep in mind that you don’t want to have more than the daily recommended amount of zinc in your diet. For adult men, it’s 11 milligrams (mg), and for women, it’s 8 mg. Too much zinc can actually inhibit immune system function.
Can Sex Boost Your Immune System?
Regular Sexual Activity Is Helpful
In a study of college students, those who had sex once or twice per week had the highest levels of immunoglobulin A (IgA) in their saliva. IgA is an immune molecule that helps protect us against illnesses like the common cold. Students who had sex once or twice per week had more salivary IgA than students who were not sexually active, infrequently sexually active (less than once a week), or who were very sexually active (three or more times per week). Enjoying sex up to a couple of times per week seems to be the sweet spot for promoting optimal IgA levels.
How does the immune system work?
Our immune system is essential for our survival. Without an immune system, our bodies would be open to attack from bacteria, viruses, parasites, and more. It is our immune system that keeps us healthy as we drift through a sea of pathogens.
This vast network of cells and tissues is constantly on the lookout for invaders, and once an enemy is spotted, a complex attack is mounted.
The immune system is spread throughout the body and involves many types of cells, organs, proteins, and tissues. Crucially, it can distinguish our tissue from foreign tissue — self from non-self. Dead and faulty cells are also recognized and cleared away by the immune system.
If the immune system encounters a pathogen, for instance, a bacterium, virus, or parasite, it mounts a so-called immune response. Later, we will explain how this works, but first, we will introduce some of the main characters in the immune system.
White blood cells are also called leukocytes. They circulate in the body in blood vessels and the lymphatic vessels that parallel the veins and arteries.
White blood cells are on constant patrol and looking for pathogens. When they find a target, they begin to multiply and send signals out to other cell types to do the same.
Our white blood cells are stored in different places in the body, which are referred to as lymphoid organs. These include the following:
- Thymus — a gland between the lungs and just below the neck.
- Spleen — an organ that filters the blood. It sits in the upper left of the abdomen.
- Bone marrow — found in the center of the bones, it also produces red blood cells.
- Lymph nodes —small glands positioned throughout the body, linked by lymphatic vessels.
There are two main types of leukocyte:
These cells surround and absorb pathogens and break them down, effectively eating them. There are several types, including:
- Neutrophils — these are the most common type of phagocyte and tend to attack bacteria.
- Monocytes — these are the largest type and have several roles.
- Macrophages — these patrol for pathogens and also remove dead and dying cells.
- Mast cells — they have many jobs, including helping to heal wounds and defend against pathogens.
Lymphocytes help the body to remember previous invaders and recognize them if they come back to attack again.
Lymphocytes begin their life in bone marrow. Some stay in the marrow and develop into B lymphocytes (B cells), others head to the thymus and become T lymphocytes (T cells). These two cell types have different roles:
- B lymphocytes — they produce antibodies and help alert the T lymphocytes.
- T lymphocytes — they destroy compromised cells in the body and help alert other leukocytes.
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How an immune response works
The immune system needs to be able to tell self from non-self. It does this by detecting proteins that are found on the surface of all cells. It learns to ignore its own or self proteins at an early stage.
An antigen is any substance that can spark an immune response.
In many cases, an antigen is a bacterium, fungus, virus, toxin, or foreign body. But it can also be one of our own cells that is faulty or dead. Initially, a range of cell types works together to recognize the antigen as an invader.
The role of B lymphocytes
Once B lymphocytes spot the antigen, they begin to secrete antibodies (antigen is short for “antibody generators”). Antibodies are special proteins that lock on to specific antigens.
Each B cell makes one specific antibody. For instance, one might make an antibody against the bacteria that cause pneumonia, and another might recognize the common cold virus.
Antibodies are part of a large family of chemicals called immunoglobulins, which play many roles in the immune response:
- Immunoglobulin G (IgG) — marks microbes so other cells can recognize and deal with them.
- IgM — is expert at killing bacteria.
- IgA — congregates in fluids, such as tears and saliva, where it protects gateways into the body.
- IgE — protects against parasites and is also to blame for allergies.
- IgD — stays bound to B lymphocytes, helping them to start the immune response.
Antibodies lock onto the antigen, but they do not kill it, only mark it for death. The killing is the job of other cells, such as phagocytes.
The role of T lymphocytes
There are distinct types of T lymphocytes:
Helper T cells (Th cells) — they coordinate the immune response. Some communicate with other cells, and some stimulate B cells to produce more antibodies. Others attract more T cells or cell-eating phagocytes.
Killer T cells (cytotoxic T lymphocytes) — as the name suggests, these T cells attack other cells. They are particularly useful for fighting viruses. They work by recognizing small parts of the virus on the outside of infected cells and destroy the infected cells.
Everyone’s immune system is different but, as a general rule, it becomes stronger during adulthood as, by this time, we have been exposed to more pathogens and developed more immunity.
That is why teens and adults tend to get sick less often than children.
Once an antibody has been produced, a copy remains in the body so that if the same antigen appears again, it can be dealt with more quickly.
That is why with some diseases, such as chickenpox, you only get it once as the body has a chickenpox antibody stored, ready and waiting to destroy it next time it arrives. This is called immunity.
There are three types of immunity in humans called innate, adaptive, and passive:
We are all born with some level of immunity to invaders. Human immune systems, similarly to those of many animals, will attack foreign invaders from day one. This innate immunity includes the external barriers of our body — the first line of defense against pathogens — such as the skin and mucous membranes of the throat and gut.
This response is more general and non-specific. If the pathogen manages to dodge the innate immune system, adaptive or acquired immunity kicks in.
Adaptive (acquired) immunity
This protect from pathogens develops as we go through life. As we are exposed to diseases or get vaccinated, we build up a library of antibodies to different pathogens. This is sometimes referred to as immunological memory because our immune system remembers previous enemies.
This type of immunity is “borrowed” from another source, but it does not last indefinitely. For instance, a baby receives antibodies from the mother through the placenta before birth and in breast milk following birth. This passive immunity protects the baby from some infections during the early years of their life.
Immunization introduces antigens or weakened pathogens to a person in such a way that the individual does not become sick but still produces antibodies. Because the body saves copies of the antibodies, it is protected if the threat should reappear later in life.
Because the immune system is so complex, there are many potential ways in which it can go wrong. Types of immune disorder fall into three categories:
These arise when one or more parts of the immune system do not function. Immunodeficiencies can be caused in a number of ways, including age, obesity, and alcoholism. In developing countries, malnutrition is a common cause. AIDS is an example of an acquired immunodeficiency.
In some cases, immunodeficiencies can be inherited, for instance, in chronic granulomatous disease where phagocytes do not function properly.
In autoimmune conditions, the immune system mistakenly targets healthy cells, rather than foreign pathogens or faulty cells. In this scenario, they cannot distinguish self from non-self.
Autoimmune diseases include celiac disease, type 1 diabetes, rheumatoid arthritis, and Graves’ disease.
With hypersensitivity, the immune system overreacts in a way that damages healthy tissue. An example is an anaphylactic shock where the body responds to an allergen so strongly that it can be life-threatening.
The immune system is incredibly complicated and utterly vital for our survival. Several different systems and cell types work in perfect synchrony (most of the time) throughout the body to fight off pathogens and clear up dead cells.
- Biology / Biochemistry
- Immune System / Vaccines
Medically reviewed by Daniel Murrell, MD on January 11, 2018 — Written by Tim