Nutrients for Preventing the Common Cold and Flu

by Dr. David Williams
Filed Under: Colds and Flu, Immune Health
Last Reviewed 02/06/2014

Targeted nutritional support can help boost your immunity

In addition to preventive lifestyle habits, the most important way to protect against the common cold and flu (including the H1N1 virus) is to bolster your immune system before you come down with a bug. Many nutrients have been shown give your immune system a significant boost if you're caught in the middle of a cold or flu outbreak.

Note: Not all of the following supplements may be right for you. Consider them all and choose the ones that you prefer and that you can stick with. They really do make a difference in how well your body can defend against the common cold, flu, H1N1, and other viruses.

Vitamin D

Research shows that optimizing your vitamin D levels is one of the very best strategies for staying healthy and avoiding the common cold, the flu, H1N1, and other seasonal viruses. Through a chain of events, vitamin D increases the production of a substance called cathelicidin in cells like natural killer cells, neutrophils, and monocytes. These are the cells of your immune system that attack invading pathogens.

The easiest way to make sure you're getting adequate vitamin D is to get out in the sun. I recommend a minimum of 15 minutes of unprotected sun exposure on any part of your body at least three times a week. For those who live in northern states, where this might not be enough, I strongly recommend that you supplement with vitamin D as well. Be aware, however, that the current recommended daily allowance of 200–600 IU (depending on age) is simply not enough. If you're getting your total vitamin D dose from a supplement, the following are my recommended daily maintenance levels:

  • 1,000 IU for children under 2 years old
  • 2,000 IU for children over 2 years old
  • 3,000 IU for individuals weighing 80–130 lbs.
  • 4,000 IU for individuals weighing 131–170 lbs.
  • 5,000 IU for individuals weighing over 170 lbs.

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Vitamin C

Vitamin C is particularly abundant in white blood cells. These cells draw in foreign invaders and then destroy them with enzymes and free radicals. Vitamin C protects the cells from being damaged during this process. It also increases the production and function of other immune system components, including natural killer cells and interferon (a biochemical messenger that promotes antiviral activity).

Vitamin C is not manufactured by the body and therefore must be obtained by other means. One way would be to eat more than the recommended five servings of fruits and vegetables daily. But since it's highly unlikely that most people get sufficient vitamin C from their diet, I strongly suggest you supplement with it. I recommend you take 2,000 mg daily.

Vitamin C is usually well tolerated, although gastrointestinal distress—particularly diarrhea—is not uncommon. You can avoid this by starting with 500 mg. Then, every three or four days, add another 500 mg until you reach 2,000 mg. If you experience any GI distress, cut back by 500 mg and stay at that dose.

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Probiotics

Having a healthy and robust colonization of friendly bacteria in your bowels is extremely important to your immune system function. Along the long length of your intestines, you have an abundance of lymph tissue that, along with the beneficial bacteria, work to process and absorb vital vitamins and minerals while preventing toxins from being reabsorbed into your bloodstream. For this reason, many researchers are now calling the intestine the primary immune organ in the body.

Another way probiotics support your immune system has to do specifically with their handling of bad bacteria. One of the major reasons bad bacteria are so detrimental to your health is that they produce numerous toxic metabolites—harmful waste products that the bad bacteria dump into your intestines and that end up circulating throughout your body, which places an enormous burden on your immune system. Healthy probiotic bacteria help to neutralize the unhealthy byproducts of bad bacteria. They also produce B vitamins and vitamin K, which are powerful antioxidants and an excellent line of defense for your body.

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Epicor

Epicor is based on the yeast Saccharomyces cerevisiae, also commonly referred to as baker's yeast or brewer's yeast. It is one of the most researched yeasts and has been used for centuries for making bread, beer, and wine. When ingested, Epicor culture increases natural killer (NK) cell activity fourfold. This increased efficiency allows the immune system to perform at superior levels with fewer NK cells—sparing the body the stress and expenditure of having to produce more NK cells.

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Whey Protein Powder

Whey is probably one of the most underutilized tools you can use to improve and protect your immune system function. It has a very high content of sulfur-containing amino acids that are necessary for the biosynthesis of glutathione. And the body's level of glutathione is a pretty good indicator of overall health and the ability of your immune system to fight off disease and counter the effects of aging.

Research has shown that several components in whey protein work together to improve immunity. A group of blood proteins called immunoglobulins (IgG1, IgG2, IgA, and IgM) are incorporated into milk and whey. They help pass on immunity to infants and adults as well. Colostrum, the first milk following birth, contains the greatest concentration of these compounds.

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Glutathione/N-Acetylcysteine (NAC)

Glutathione is a tripeptide composed of three amino acids: glycine, glutamic acid, and cysteine. It's a compound that is present in every cell of your body and essential for life itself. If each of us had a "glutathione gauge" on our body, similar to the gas gauge in our car, we'd want to keep it as full as possible because it's so important to healthy immune function and healthy aging.

All food groups contain glutathione, but cruciferous vegetables, such as Brussels sprouts, cauliflower, broccoli, cabbage, kale, bok choy, cress, mustard greens, horseradish, turnips, rutabagas, and kohlrabi are the richest sources. Because these aren't diet favorites of many people, I suggest that you supplement to get adequate amounts of glutathione.

Glutathione is not very well absorbed in supplement form, so I recommend that you use its precursor, N-acetylcysteine (NAC). This form is metabolized or converted by the body into glutathione, and it has been proven to do a better job of raising your body's glutathione levels. A trustworthy manufacturer of NAC is Jo Mar Laboratories.

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Propolis

Propolis is the brown, waxy, sticky resin that bees collect from oozing tree buds that has amazing antiseptic, antibacterial, antifungal, antiviral, anti-amoebic, anti-inflammatory, and antipyretic (fever-reducing) properties. It's available in tablets, capsules, and liquid, as well as in salves for topical use, and can be found in health food stores, or from CC Pollen.

The recommended maintenance dosages are generally 500–1,000 mg per day in tablet and capsule form. It's rare, but some people can be allergic to bee products, so it would be wise to start with small doses of propolis first to see if you experience a problem.

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Selenium

Selenium is a trace mineral that the body incorporates into proteins to make over 25 different selenoproteins (like the enzyme glutathione peroxidase)—some of the strongest antioxidants that work to prevent cellular damage from free radicals.

A few years ago, researchers working with the flu virus discovered that, when animals with selenium deficiency were contaminated with the flu virus, the virus mutated into a far more virulent form when it was passed on to the next animal. The researchers compared the initial virus to the mutated form, saying that the first would typically cause only a mild pneumonia, while the latter would result in life-threatening severe pneumonia. In simple terms, selenium deficiencies cause viral mutations that could turn a harmless flu bug into a worldwide, life-threatening flu pandemic.

I recommend that you get 400 mcg of selenium daily. Selenium is often included in many quality multivitamin/mineral formulas.

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