Top Foods for Immune System

Boosting your immune system is a topic that usually comes up as winter sets in. Adults and children start to get the sniffles. The yearly discussion about flu shots starts up again with all the arguments for and against. Magazines run articles on how to stave off winter illnesses like the common cold.

So, most of us are aware that the immune system protects us from bacteria, viruses and other pathogens. But, when we acquire a disease such as heart disease, diabetes or cancer, your immune system playes an even bigger role to protect you from these devastating diseases. In fact, it is your immune system that helps to repair your body from the damage caused by disease.

Unfortuately, many of the drugs that you are given don't really strengthen your immune system. In fact, some of these drugs, such as the drugs for chemotherapy, almost destroy your immune system.

So, before you give in to your doctors coaxing and fear tactics to get chemotherapy, consider a natural alternative treatment that won't destroy your immune system. If the alternative treatment doesn't work, you can always come back and get the chemotherapy. But, if you get the chemotherapy first, it will make it a lot more difficult to recover from the damage caused by the chemotherapy. Ironically, when it comes to cancer, it is your immune system that will play one of the biggest roles in fighting the cancer and healing your body.

The following is a list of some of the top foods that help to strengthen your immune system and, in some cases, fight your cancer. For specific foods that strengthen your immune system and fight your cancer, refer to our blog post titled "Top Foods That Fight Cancer".

Berries
Vitamin C is present in berries in very large amounts. Vitamin C prevents injury to cells and is therefore very useful in boosting your immune system. Blueberries and other dark berries in particular contain large doses of bioflavonoids that can act as antioxidants which will attack the free radicals moving around your body.

Blueberries in particular are potent immune boosters as they contain powerful phytochemicals, such as anthocyanins, which is the pigment that gives blueberries their color.

Carrots (Juicing)
Carrots contain beta carotene, which increases the number of infection-fighting cells, natural killer cells, and helper T-cells, as well as being a powerful antioxidant that mops up excess free radicals that accelerate aging -- especially when the carrots are juiced.

Beta carotene reduces the risk of cardiovascular disease by interfering with how the fats and cholesterol in the bloodstream oxidize to form arterial plaques. Studies have shown that foods that boost your immune system containing beta carotene can lower the risk of cardiovascular disease, especially strokes and heart attacks, giving scientific credence to the belief that a carrot a day can keep the heart surgeon away.

Beta carotene also protects against cancer by stimulating the immune cells called macrophages to produce tumor necrosis factor, which kills cancer cells. It has also been shown that beta carotene supplements can increase the production of T-cell lymphocytes and natural killer cells and can enhance the ability of the natural killer cells to attack cancer cells.

Getting carotenoids in food, especially raw carrot juice, is a lot more cancer-protective than taking beta carotene supplements. The body converts beta carotene to vitamin A, which itself has anticancer properties and immune-boosting functions.

Since too much vitamin A can be toxic to the body, it’s better to get extra beta carotene from foods and let the body naturally regulate how much of this precursor is converted to the immune-fighting vitamin A. It’s highly unlikely that a person could take in enough beta carotene to produce a toxic amount of vitamin A, because when the body has enough vitamin A, it stops making it.

Chlorella
Chlorella is a single-cell freshwater algae that acts as an efficient detoxification agent by binding to toxins, such as mercury, and carries them out of your system. It is the chlorophyll in chlorella that makes it so powerful. Chlorophyll helps you process more oxygen, cleanses your blood and promotes the growth and repair of your tissues. Wheatgrass, because of its chlorophyll content, provides a similar benefit.

Citrus Fruits
Citrus fruits and vegetables contain Vitamin C and phytonutrients called bioflavenoids, which aid the immune system by protecting the cells of the body against environmental foods-that-boost-your-immune-systempollutants.

Bioflavenoids protect the cell membranes against the pollutants trying to attach to them. Along the membrane of each cell there are microscopic parking spaces, called receptor sites. Pollutants, toxins, or germs can park here and gradually eat their way into the membrane of the cell, but when bioflavenoids fill up these parking spots there is no room for toxins to park.

Bioflavenoids also reduce the cholesterol’s ability to form plaques in arteries and lessen the formation of microscopic clots inside arteries, which can lead to heart attack and stroke. Studies have shown that people who eat the most bioflavenoids have less cardiovascular disease.

A diet that contains a wide variety of foods that boost your immune system like fruits and vegetables, at least six servings per day, will help you get the bioflavenoids needed to help your immune system work in top form.

Cruciferous Vegetables
Cauliflower, broccoli, and Brussels sprouts are all cruciferous vegetables, which means they’re not only rich in antioxidant vitamins that give an immune system boost, but they also contain sulfur, which helps to penetrate cancer cells.

These vegetables also contain choline, which keeps your cells functioning properly and also helps support a healthy gastrointestinal barrier, keeping bacteria safely confined in the gut. Cauliflower, in particular, is a beneficial food to eat when you’re sick because it’s also rich in glutathione, a powerful antioxidant that helps fight off infection. Dip raw cauliflower florets in low-fat yogurt, drizzle them with vinaigrette, or add them to your favorite vegetable soup recipe.

Fish
Fish, especially cold-water fish, is a great source of omega 3 fats, which many people are deficient in. Choose fish like tuna, mackerel, sardines and wild salmon to obtain the higher levels of Omega-3 essential fatty acids.

Garlic
With antiviral properties and antibacterial features, garlic is one of the most powerful foods that boost your immune system stimulates the multiplication of infection-fighting white cells, boosts natural killer cell activity, and increases the efficiency of antibody production.

The immune-boosting properties of garlic are due to its sulfur-containing compounds, such as allicin and sulfides. Garlic can also act as an antioxidant that reduces the build-up of free radicals in the bloodstream.

Garlic protects against cancer, as demonstrated by cultures with a garlic-rich diet have a lower incidence of intestinal cancer. Garlic may also play a part in getting rid of potential carcinogens and other toxic substances. It is also one of the most heart-friendly foods that boost your immune system since it keeps platelets from sticking together and clogging tiny blood vessels.

Garlic is one of the easiest foods to include in your diet. Add it into soups, casseroles and sauces. Include it in salad dressings or roast it with vegetables. There are so many options to use garlic every day.

Grapefruit
Red or pink grapefruit is packed with vitamin C, making it an immune-boosting essential. The red and pink varieties are especially good choices because, as their rosy color indicates, they’re packed with bioflavonoids. These naturally-occurring compounds cause beneficial reactions in the body, including an added immunity boost. Halve a grapefruit  and dust it with cinnamon, another immunity booster.

Greens
Greens such as kale, spinach, collards, and Swiss chard are immune-boosting foods that contain high levels of vitamin C, which not only packs a powerful antioxidant punch, it helps fight off infection and regenerate other antioxidants in the body, including vitamin E. They also contain folate, another immune booster.

Add to a green smoothie or sautée kale, spinach, or Swiss chard with garlic and olive oil, or use fresh spinach to make an nutrient-rich salad — top it with fresh mushrooms to pack an extra immune-boosting punch.

Mushrooms
If you want your body to fight infection, certain mushrooms can increase the activity and new production of white blood cells.

No herbal medicine cabinet should be without mushrooms. They increase the production of cytokines, which are cells that help fight off infection. They also contain polysaccharides, which are compounds that support the immune system.

Mushrooms also contain powerful compounds called beta-glucans, which have been long known for their immune enhancing and cancer-fighting properties. Beta-glucan 3 enhances immunity through a variety of mechanisms, many of which are similar to those of echinacea and astragalus root. For example, it binds to macrophages and other scavenger white blood cells, activating their anti-infection activities.

When you’re thinking about a healthy diet, mushrooms may not be the first thing to come to mind, but they’re a major source of the immune system-boosting mineral, zinc. People who don’t have enough zinc in their diet tend to have fewer white blood cells to help fight off disease, which can lead to a reduced immune response.

Start thinking of mushrooms as a great immune-boosting food. Sauté shiitakes with onion and garlic as a side dish or add to enrich tomato sauce or a salad.

There are many different types of mushrooms, but stick with the medicinal mushrooms such as Reishi, Shiitake, and Maitake, which are notable for their ability to activate/modulate your immune system.

"Studies show that mushrooms increase the production and activity of white blood cells, making them more aggressive. This is a good thing when you have an infection," says Douglas Schar, MCPP,  director of the Institute of Herbal Medicine in Washington, DC.

Omega-3 Fatty Acids
The omega-3 fatty acids in flax oil and fatty fish (such as salmon, tuna, and mackerel) act as immune boosters by increasing the activity of phagocytes, the white blood cells that eat up bacteria.

Essential fatty acids also protect the body against damage from over-reactions to infection. When taking essential fatty acid supplements, such as flax or fish oils, take additional vitamin E, which acts together with essential fatty acids to boost the immune system. One way to get more omega-3 fatty acids in your diet is to add one to three teaspoons of flax oil to a fruit and yogurt smoothie or eat some cold-water fish such as wild salmon or sardines.

A study found that children taking a half teaspoon of flax oil a day experienced fewer and less severe respiratory infections and fewer days of being absent from school. (Perhaps this is why grandmothers used to insist on a daily dose of unpalatable cod liver oil.)

Probiotics
Probiotics, or the "live active cultures" found in yogurt, are healthy bacteria that keep the gut and intestinal tract free of disease-causing germs.

Although they're available in supplement form, a study from the University of Vienna in Austria found that a daily 7-ounce dose of organic  yogurt was just as effective in boosting immunity as popping pills.

In an 80-day Swedish study of 181 factory employees, those who drank a daily supplement of Lactobacillus reuteri—a specific probiotic that appears to stimulate white blood cells—took 33 percent fewer sick days than those given a placebo.

Selenium
This mineral increases natural killer cells and mobilizes cancer-fighting cells. Foods that boost your immune system containing selenium are tuna, red snapper, lobster, shrimp, whole grains, vegetables (depending on the selenium content of the soil they’re grown in), brown rice, egg yolks, cottage cheese, chicken (white meat), sunflower seeds, garlic, Brazil nuts, and lamb chops.

Spices
Ginger comes to the aid when we're sick in some powerful ways. Besides soothing a scratchy throat, it has chemicals called sesquiterpenes that target rhinoviruses -- which are the most common family of cold viruses -- as well as substances that help suppress coughing. Ginger is also a natural pain and fever reducer and a mild sedative so you'll feel more comfortable and be able to rest easier. Add a couple of tablespoons of shredded ginger root to your tea, or make ginger tea (it comes in tea bags, but you can also simmer fresh sliced ginger to make a potent brew).

Turmeric, a bright-yellow, bitter spice and a key ingredient in many curries, has been used for years as an anti-inflammatory in treating both osteoarthritis and rheumatoid arthritis. High concentrations of curcumin, which gives turmeric its distinct color, have been shown to contain strong flu and cold fighting properties.

It's ironic that black pepper -- the spice best known for making you sneeze -- can ward off the sniffles. Black peppercorns are high in piperine, a compound known for its anti-fever and pain-relieving qualities. Black pepper also helps your body to better absorb turmeric.

Spicy Foods
Hot and spicy foods that boost your immune system such as chili peppers, hot mustard, radishes, pepper, onions, and garlic contain substances called “mucolytics” (similar to over-the-counter expectorant cough syrups) that liquefy thick mucus that accumulates in the sinuses and breathing passages.

Sweet Potatoes
Sweet potatoes contain large doses of vitamin A. Our skin needs good amounts of vitamin A to keep it healthy. When the largest organ in your body is healthy, you have a much better chance of staving off infection.

You may not think of skin as part of your immune system, but this crucial organ, covering an impressive 16 square feet, serves as a first-line of defense against bacteria, viruses, and other undesirables. To stay strong and healthy, your skin needs vitamin A.

"Vitamin A plays a major role in the production of connective tissue, a key component of skin," explains Prevention advisor David Katz, MD, director of the Yale-Griffin Prevention Research Center in Derby, CT. "One of the best ways to get vitamin A into your diet is from foods containing beta-carotene (like sweet potatoes), which your body turns into vitamin A."

Vegetables
You probably already know that you should eat a variety of the green and colorful vegetables. But do you know why? The bright green, yellow and orange vegetables have the highest amounts of anticancer phytonutrients and carotenoids like beta carotene. These are antioxidants which help your immune system to keep in shape.

Try a large variety of vegetables in salads every day and include these vegetables in hearty soups.

Vegetable soups. Soups that are made with an array vegetables such as celery, carrots, squash, and red peppers contain key nutrients that will strengthen your immune system. Also, single-vegetable soups such as tomato soup also helps to boost your immune system. Researchers speculate that the lycopene in tomatoes acts as an antioxidant, helping white blood cells resist the damaging effects of free radicals.

Green salads. Similarly, salads that are made with an array vegetables such as broccoli florets, celery, carrots, squash, onions and red peppers contain key nutrients that will strengthen your immune system.

Green juices/smoothies. These drinks are packed with concentrated phytonutrients that help to boost your immune system.

Vitamin C
Vitamin C tops the list of foods that boost your immune system for many reasons. There has been more research about the immune-boosting effects of Vitamin C than perhaps any other nutrient. Vitamin C supplements are inexpensive to produce, and it’s available naturally in many fruits and vegetables. Also, you can buy a vitamin-C-fortified version of just about anything. Here’s what the research shows about how this mighty vitamin protects your body.

Foods that boost your immune system containing vitamin C increase the production of infection-fighting white blood cells and antibodies and increases levels of interferon, the antibody that coats cell surfaces, preventing the entry of viruses. Vitamin C reduces the risk of cardiovascular disease by raising levels of HDL (good) cholesterol while lowering blood pressure and interfering with the process by which fat is converted to plaque in the arteries. As an added perk, persons whose diets are higher in vitamin C have lower rates of colon, prostate, and breast cancer.

Around 200 milligrams a day seems to be a generally agreed-upon amount and one that can be automatically obtained by eating at least six servings of fruits and vegetables a day. If you take vitamin C supplements, it’s best to space them throughout the day rather than take one large dose, most of which may end up being excreted in the urine.

Studies have found that Vitamin C can reduce cold symptoms by 23 per cent, and all that's needed is just one to eight grams (1,000 to 8,000 milligrams) to do the trick. Besides citrus fruits, other foods that have high amounts of vitamin C include papaya, sweet potatoes, butternut squash, tomatoes, broccoli, Brussels sprouts and red bell peppers.

Vitamin E
This important antioxidant and immune booster doesn’t get as much press as vitamin C, yet it’s one of the most important foods that boost your immune system.

Vitamin E stimulates the production of natural killer cells, those that seek out and destroy germs and cancer cells. Vitamin E enhances the production of B-cells, the immune cells that produce antibodies that destroy bacteria.

Vitamin E supplementation may also reverse some of the decline in immune response commonly seen in aging. Vitamin E has been implicated in lowering the risk of cardiovascular disease. In the Harvard School of Public Health study of 87,000 nurses, Vitamin E supplementation was shown to cut the risk of heart attacks by fifty percent.

It’s not difficult to get 30 to 60 milligrams every day of Vitamin E from a diet rich in seeds, vegetable oils, and grains, but it’s difficult for most people to consume more than 60 milligrams a day consistently through diet alone. Supplements may be necessary to get enough vitamin E to boost your immune system.

You need 100-400 milligrams per day, depending on your general lifestyle. People who don’t exercise, who smoke, and who consume high amounts of alcoholic beverages will need the higher dosage. Those with a more moderate lifestyle can get by with lower levels of supplementation.

Whey Protein
Whey protein helps to fight cancer because it helps our bodies increase our glutathione levels and it provides an easy-to-digest protein that helps the body rebuild and repair its cells due to the damage from the cancer. High-quality whey protein provides many other health benefits including, immunity, cell energy, muscle strength, detox and antioxidant support.

Glutathione is a terrific antioxidant and cellular detoxifier, helping to break down the adverse effects of environmental toxins, from heavy metals to tobacco smoke and diesel fumes. It is produced in all cells of the body, specifically to break down these dangerous toxins and free-radicals.

Lactoferrin is a key ingredient in high-quality whey protein that is a cancer killer and triggers the production of glutathione. Lactoferrin activates the innate immune system cells like the macrophages, neutrophils  and T-cells. These are the first line of defense against harmful pathogens – including cancer cells.

Cancer cells have a highly negative membrane charge which attracts lactoferrin, while healthy normal cells have a neutral charge. Lactoferrin is attracted to the cancer cells, attaches to them and triggers a process that kills the cancer cell; as well as blocking angiogenesis – the growth of blood vessels that feed cancer cells.

Another key to lactoferrin’s cancer-fighting properties is its amazing ability to bind with iron. It forms a bond with iron that’s 100 times stronger than transferrin – your body’s major iron transport protein. Several studies suggest that excessive amounts of iron, in your diet, increase your risk of developing certain types of cancer. Researchers have shown that many chronic diseases – in particular, cancer – need iron to reproduce and grow.

High-quality whey protein provides cancer patients with an easy way to enhance lean muscle mass and boost their energy in order to fight cachexia. Cachexia is a wasting condition with loss of muscle and fat tissue; and, is one of the reasons why some cancer patients succumb to their disease.

Note: Besides high-quality whey protein, other foods that help to increase glutathione levels include green vegetables like Brussels sprouts, cabbage, cauliflower and broccoli along with avocado, asparagus, chlorella, wheatgrass, grapefruit, strawberries, raw tomatoes, and oranges.

Zinc
This valuable mineral increases the production of white blood cells that fight infection and helps them fight more aggressively. It also increases killer cells that fight against cancer and helps white cells release more antibodies.

Zinc supplements have been shown to slow the growth of cancer. Zinc increases the number of infection-fighting T-cells, especially in elderly people who are often deficient in zinc, and whose immune system often weakens with age.

The anti-infection hype around zinc is controversial. While some studies claim that zinc supplements in the form of lozenges can lower the incidence and severity of infections, other studies have failed to show this correlation.

A word of caution: too much zinc in the form of supplements (more than 75 milligrams a day) can inhibit immune function. It’s safest to stick to getting zinc from your diet and aim for 15 to 25 milligrams a day.

For infants and children, there is some evidence that dietary zinc supplements may reduce the incidence of acute respiratory infections, but this is controversial.

Rich food sources of zinc include: oysters, cereals, crab, beef, turkey and beans.