Nutrition is one of the best ways to enhance active immunity to keep your body healthy and strong. Read about certain immune-boosting foods, vitamins and supplements that increase your odds of staying healthy.
Feed Your Immune System
Adequately feeding your immune system boosts its fighting power. Immune boosters work in many ways. They increase the number of white cells in the immune system army, train them to fight better, and help them form an overall better battle plan. Boosters also help to eliminate the deadwood in the army, substances that drag the body down. Here are eight highly suggested nutrients to add to your family’s diet to cut down on days missed from work and school because of illness.
1. Vitamin C
Vitamin C tops the list of immune boosters 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.
Vitamin C increases 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.
You don’t have to take in massive amounts of vitamin C to boost your immune system. 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.
2. Vitamin E
This important antioxidant and immune booster doesn’t get as much press as vitamin C, yet it’s important to a healthy 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.
Beta carotene 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. Like the other “big three” antioxidants, vitamins C and E, it 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 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.
Beta carotene is the most familiar carotenoid, but it is only one member of a large family. Researchers believe that it is not just beta carotene that produces all these good effects, but all the carotenoids working together. This is why getting carotenoids in food may be 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. But too much vitamin A can be toxic to the body, so 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.
A group of phytonutrients called bioflavenoids aids the immune system by protecting the cells of the body against environmental pollutants. 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 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.
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. The best source of zinc for infants and young children is zinc-fortified cereals.
RICH SOURCES OF ZINC: Food Source of Zinc Serving Size Zinc (in milligrams) Oysters 6 medium 76 Zinc-fortified cereals 1 ounce 0-15 Crab 3 ounces 7 Beef 3 ounces 6 Turkey, dark meat 3 ounces 3.8 Beans 1/2 cup 1.2-1.8
This flavorful member of the onion family is a powerful immune booster that 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 seem to be 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 may protect against cancer, though the evidence is controversial. 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 a heart-friendly food since it keeps platelets from sticking together and clogging tiny blood vessels.
This mineral increases natural killer cells and mobilizes cancer-fighting cells. Best food sources of 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.
8. Omega-3 fatty acids
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. 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. (Perhaps this is why grandmothers used to insist on a daily dose of unpalatable cod liver oil.) 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.
Hot Foods for Colds: hot foods 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.
FDA Advisory On Alfalfa Sprouts
The Food and Drug Administration is reaffirming health advisories that persons who are at high risk for severe foodborne disease should avoid eating raw alfalfa sprouts. This reaffirmation is an interim measure until such time as intervention methods are in place to improve the safety of these products. Persons at high risk include children, the elderly, and persons with compromised immune systems. Similar advice was given by the Centers for Disease Control and Prevention (CDC) after reporting outbreaks of E. Coli O157:H7 in its Morbidity and Mortality Weekly Report (MMWR) publication in August 1997.
Since 1995, raw sprouts have emerged as a recognized source of foodborne illness in the United States. FDA’s reaffirmation of this advice follows a recent investigation by the state of California of 3 Salmonella and E. Coli O157 outbreaks associated with sprouts that affected a total of approximately 60 persons. The California Department of Health Services has issued a statewide advisory about the potential risk of illness to vulnerable populations.
An E. coli O157 infection can lead to hemolytic uremic syndrome with resultant kidney failure or death in children, and equally serious complications in the elderly. Salmonella infections can cause serious illness in children, the elderly and the immune compromised. Healthy persons infected with these bacteria experience diarrhea, nausea, abdominal cramping or fever for several days, but generally, the illness is self-limiting.
The International Sprout Growers Association (ISGA) is taking positive steps to address this problem. For example, the sprout industry is pursuing the use of calcium hypochlorite at 20,000 parts per million (a 2 percent solution) for soaking of the seeds prior to germination and growth. This method of treating seeds has the potential to substantially reduce microbial contamination of seeds which can be passed on through the growing sprouts. The Environmental Protection Agency is expediting evaluation of this procedure. The ISGA is working with FDA and the California Department of Health Services to develop and implement a food safety program for sprout growers.
CDC and FDA have closely monitored the occurrence of foodborne illness outbreaks associated with sprouts, and FDA has been working with other agencies and industry to develop a strategy to enhance the safety of sprouts. Among the steps that have been taken are these:
- FDA and CDC met with the sprout industry in 1995 to inform them of recent outbreaks and government concerns about the safety of sprouts.
- In July 1997, FDA and CDC charged the National Advisory Committee on Microbiological Criteria for Foods (NACMCF) with reviewing available data on sprout-associated outbreaks and providing recommendations on intervention and prevention methods. (NACMCF is an expert scientific panel which advises the federal government on food safety matters).
- The industry is also actively working with FDA and USDA’s Agricultural Research Service on other interventions including irradiation to address the problem.
- FDA has issued a nationwide field assignment to determine current sprout industry practices during growing, washing, and packaging. Samples of seeds, processing water, and sprouts are being analyzed microbiologically. Enforcement actions will be considered as appropriate.
- The California Department of Health Services and FDA’s Pacific Regional Office, in cooperation with the sprout industry, recently conducted a survey of growers in California. Information gathered during this survey was used to develop the current FDA nationwide assignment.
- On September 3-4, 1998, FDA will meet with industry representatives in Chicago to discuss ongoing cooperative research toward ensuring the safety of sprouts.
- On September 28 and 29, 1998, FDA will hold a public meeting on the safety of sprouts to provide a forum for discussion of the current situation, consumer perspectives, agricultural practices, the state of the science, and possible intervention methods.
FDA and other public health agencies will continue to work with healthcare professionals in raising awareness about this potential risk. Consumers who have eaten raw sprouts and are experiencing severe diarrhea or other extreme symptoms of foodborne infections are advised to consult their healthcare providers.
Garlic Fights More than Vampires
Will a clove a day keep the doctor away? That’s what John A. Milner, head of the department of nutrition at The Pennsylvania State University College of Health and Human Development, believes. Milner has led a number of studies that indicate that eating garlic (Allium sativum, a member of the lily family) may help reduce the incidence of breast cancer.
Garlic stimulates the body’s immune system, boosting the killing ability of natural killer cells and increasing macrophage activity. Garlic also works against heart disease and strokes by lowering cholesterol levels and blood pressure. As an anticancer agent, Milner and others’ work shows that garlic slows tumor growth and protects against potential damage from oxidation, free radicals, and nuclear radiation.
Garlic has long been a folk-remedy favorite–ancient manuscripts from Sumer, Egypt, China, and Greece describe the use of garlic for treating everything from snake bites to epilepsy. There is now scientific evidence that the bulbous herb is effective against cancer. Over the last decade, Milner has published and presented numerous studies on the anticancer effects of garlic. In a study published in the October 1992 issue of Carcinogenesis, Milner and colleagues tested the effect of garlic on mammary tumors in rats. They found that dietary garlic administered in powder form caused significant delays in the onset of first mammary tumors and reduced the final number of tumors. The team found that consuming garlic powder depressed the binding of the potent carcinogen 7,12-dimethylbenz(a)anthracene to mammary cell DNA in the rats, which may explain why fewer tumors developed.
In a study published in the 15 October 1993 issue of Cancer Letters, Milner and Sujatha Sundaram, a doctoral candidate at Penn State, tested the effect of six organosulfur compounds found in garlic on the growth of canine mammary tumor cells in culture. Three of the compounds–diallyl sulfide, diallyl disulfide, and diallyl trisulfide–sharply curbed the proliferation of tumor cells.
In the 19 April 1996 issue of Cancer Letters, Milner and research assistant Eric Schaffer compared the effect of garlic powder, the water-soluble compound S-allyl cysteine, and diallyl disulfide on the incidence of mammary tumors induced by N-methyl-N-nitrosourea. All three compounds were found to delay the onset of mammary tumors in female rats, and to reduce the overall incidence of tumors. Garlic powder led the race, with an 81% reduction in tumor incidence.
Finally, in a study published in the January 1994 issue of the American Journal of Epidemiology, a team of scientists from the University of Minnesota in Minneapolis and the University of Washington in Seattle looked at the effects of 15 different fruits and vegetables on tumors among a group of women from the Iowa Women’s Health Study. Of all the fruits and vegetables studied, garlic was found to have the most dramatic relationship with tumor incidence. According to the scientists, consumption of garlic was inversely associated with risk for colon cancer, with a relative risk of 0.68 for the uppermost versus the lowermost consumption levels.
Milner and others must now delineate under what circumstances garlic works, and exactly what it’s doing that’s so beneficial. Along with Kun Song, a doctoral candidate in the department of nutrition, Milner conducted a study showing that heating in a microwave or conventional oven can completely strip garlic of its cancer-fighting benefits. However, if the garlic is minced or crushed and allowed to stand for at least 10 minutes before heating, there is little or no loss of benefits. The 10-minute standing period allows the enzyme alliinase in the garlic to begin producing allyl sulfur compounds–the compounds with the cancer-fighting properties. If the garlic is cooked immediately after chopping, the heating process deactivates the enzyme and the anticarcinogenic effects of the garlic are lost. Milner presented these findings at a symposium entitled Recent Advances on the Nutritional Benefits Accompanying the Use of Garlic as a Supplement, held in Newport Beach, California, 15-17 November 1998.
So far, the only known adverse health effects from eating too much garlic are gastrointestinal bleeding and stomach upset, plus of course the much-maligned garlic breath. But garlic’s rising popularity–thanks to the increasing public and scientific interest in herbal medicine–means that consumers have a choice of ways to take their medicine, including some odorless varieties. Milner says that many of the commercially available garlic preparations that he and colleagues have tested, including deodorized varieties, have anticancer properties. There is little reason to avoid garlic and many reasons to enjoy it, says Milner–in whatever preparation desired.
Recipe for Immune Boosting Smoothie
Children often don’t feel like eating following a cold or illness. Their nutrition suffers and their immune system suffers. This accounts for the common occurrence of getting one infection after another. It’s best to keep so well nourished that the nutritional reserves can withstand several days of poor eating. Drink this smoothie daily upon school entry in September, upon beginning daycare, upon exposure to a contagious illness, or when you or your child feels a cold coming on.
2 cups milk or soy or rice beverage
1 cup plain nonfat yogurt
1 serving of a multinutrient supplement one frozen banana, cut up
1/2 cup frozen blueberries
1/2 cup each of your favorite fruit, frozen (e.g., organic strawberries, papaya, mango)
1 tbsp. flax oil or 2 tbsp. flaxseed meal (Because fiber steadies the absorption of carbohydrates and therefore contributes to a steadier blood sugar we suggest using rich sources of fiber, such as flaxseed meal (i.e., ground flax seeds, containing both the oil and fiber), although flax oil has a more palatable consistency than flaxseed meal. For additional fiber, if you don’t mind an even grainier texture, add 1 tbsp. or more of oat bran.)
- 3 ounces tofu
- 10 mg. zinc
- 100 mcg. selenium
- 50-100 IU vitamin E
- 1 serving soy isolate powder (optional)
- 2 tbsp. peanut butter (optional)
Combine all the ingredients and blend until smooth. Serve immediately after blending while the mixture still has a bubbly milkshake-like consistency.
How Plant Foods Boost Your Immune System
by Mike Johnston, summarized from a report by PCRM
Unfortunately, our air, water, soil and much of our food is full of chemicals that can cause health problems ranging from asthma to cancer. The good news, however, is that a natural chemical removal system is built into our basic biochemistry. It is powerful enough to eliminate thousands of different chemicals. It just needs to be turned on.
This chemical rejection process is based on enzymes that can take the most dangerous chemicals and, in an instant, render them harmless. These enzymes arrest toxins and send them away, so they can, in fact, save your life but they need to be woken up to do their thing. This involves a two-phase process. In Phase I, an enzyme in the liver cell grabs hold of the toxic molecule and attaches oxygen to it. In Phase II, a second enzyme hooks the culprit molecule onto a large carrier molecule that drags it away. These are then sent out of your body in your urine or feces.
As this process unfolds however, there is one very dangerous point. When a toxic chemical has had oxygen attached by the Phase I enzyme, it can be even more dangerous than when it entered your body. The key is to have plenty of Phase II enzymes around to deal with these activated toxins and kick them out of your body. This phenomenon depends on the right kinds of food in your diet. Some foods contain powerful enzyme inducers. They cause the body to make more Phase II enzymes. Some of these foods are broccoli, cabbage, Brussels sprouts and cauliflower. These vegetables also work well at detoxifying cancer-causing chemicals in beef. Note however, that none of the vegetables reduces the risk to zero, so avoiding beef is still the healthiest strategy.
Soybean products, such as tofu, tempeh, and soy milk, also contain natural compounds that stimulate your body to make more of these helpful Phase II enzymes, which may be part of the reason why Asian countries have especially low rates of most cancers. Green onions are also potent enzyme boosters, as are many other vegetables. Cooking does not destroy them.
We are confronted by new chemicals every day and our natural enzyme systems are busy trying to disarm them. They even try to destroy medications. Researchers at Rockefeller University in New York gave Brussels sprouts and cabbage to research subjects over the course of several days. They then tested their response to phenacetin and antipyrine, two analgesic and anti-inflammatory drugs. They found that when subjects were on the vegetable-rich diet, they tended to eliminate each medicine more rapidly. Tests with many other medications have shown the same result, although the response varies from one person to the next.
Don’t let this scare you. It does not mean that medicines do not work on vegetarians. It simply means that plant-based diets make your body more ready and able to knock out chemicals of many types. Overall, that is a great plus, although it may mean that some medicines are eliminated a bit faster than they might be otherwise.
Source: Good Medicine, Autumn 1995, The newsletter of the Physicians Committee for Responsible Medicine (PCRM).
What Are Some Foods That May Help Boost Immunity?
Excellent nutritional status enhances the ability to fight infections. It is important to follow a well-balanced diet that provides adequate nutrition for maintenance or improvement in nutritional status and prevents vitamin and mineral deficiencies. Three or more meals and snacks each day can provide the nutrients needed to provide a strong immune system. Several vitamin and mineral deficiencies are known to affect immune function. Therefore, a multivitamin and mineral supplement can be taken, especially for those with a poor dietary intake. We suggest you follow a healthy diet rich in vitamins and minerals. A healthy diet is high in carbohydrate and fibre and low in fat. It is very difficult to give specific advice regarding food intake over the net as there are many factors which come into play.
Immunity is also affected by free radicals. Free radicals are molecules that are all around us. They are produced both as a natural product of living (through metabolism) and by outside sources such as sunlight, cigarette smoke and general pollution. Free radicals are used by the immune system to fight off invading bacteria and viruses. However, when produced in excess they damage human cells and tissues too. In fact free radicals are implicated as causes in many diseases of lifestyle including cancer. Our natural defense mechanisms called antioxidants are usually able to mop up the majority of these aggressive molecules. The most potent antioxidant nutrients are vit A, C, E, beta-carotene and selenium. It is important to ensure adequate intake of fruit and vegetables that are known to be rich in antioxidants.
Sterols are thought to boost the body’s defense mechanisms, and may therefore be good for daily immune support. They have been shown to modulate the functions of T-cells (cells which control and regulate the immune response) by enhancing their cellular division and their secretion of important factors called lymphokines. The activities of these cells are of the utmost importance in fighting off viral diseases or diseases involving bacteria which live inside cells, for example, tuberculosis. Along the same lines, sterols reduce susceptibility to infection and daily supplementation is thought to reduce incidence of colds and flus.
Some important nutrients in immunity include:
The B-complex vitamins are a group of eight inter-related vitamins, which occur together in natural plant and animal sources. Because these vitamins are water soluble, they cannot be stored to any large degree in the body and therefore must be taken in daily. They are easily lost through refining, processing, cooking and peeling of foods. Rich sources of B vitamins are green vegetables, potatoes, wholegrain cereals, fresh and dried fruit, pulses (peas, beans and lentils), nuts, seeds, liver and lean meat.
Vitamin C is a water-soluble vitamin that also cannot be stored by the body, and has to be included in the daily diet. It is used up more rapidly during stressful conditions and thus requirements during such times are increased. This vitamin is needed to help the body to resist infection, and for the vital role it plays in wound healing. It also protects against dangerous free radicals, as mentioned above and is a powerful antioxidant. Vitamin C can be found in fresh fruits, especially citrus fruits and blackcurrants, fruit juices and fresh vegetables.
This mineral is required for its role in resistance to infection and wound healing. It can be found in liver and red meat, egg yolks, dairy products, wholegrain cereals and seafood – particularly oysters and shellfish.
Magnesium is extremely important – it is a mineral essential for activating chemical reactions, transporting glucose to the cells and boosting your immune system. At times of high psychological stress, our magnesium requirements are even higher. This mineral can be found in oysters, shellfish, herring, liver, legumes and milk.