Every year as winter rolls around, we fear the cold or flu that will knock us off our feet for a week. The winter season brings with it a wide array of cold and flu viruses that make their rounds across America.
Approximately 62 million Americans will miss work due to a flu-related illness this coming season.
In "The Flu Vaccine: What You Need to Know," I talked about natural prevention strategies for the flu that include vitamin D, elderberry and zinc. These should be part of your medicine toolkit to help ward off colds and flu.
To winterize your immune system, use these super-immunity herbs and mushrooms:
Astragalus is my number one favorite winter immune tonic. A plant with long stems and purple flowers, the astragalus is harvested for its roots. Within these roots are astragalosides, plant constituents that stimulate the immune system.
The dried root may be added to soup or decoction, which is an infusion made by boiling the roots. It may also be taken in a capsule or extract.
Take 250 mg daily or drink a decoction of the powdered root several times a week to keep your immune system strong during cold and flu season.
Beta-glucans are chains of glucose molecules attached end-to-end, with branching side chains being the most immunologically active. Molecular chemistry aside, beta glucans are powerful "biological response modifiers" able to activate our innate immune system. 
Another study found that mice given yeast Beta-glucan with or without antibiotics were protected against anthrax infection.
Most studies used 1,3 beta-glucan sourced from the Saccharomyces cerevisiae yeast. You can also find this powerful immune system booster in several mushrooms used in every day cooking, such as Reishi, Shiitake and Maitake.
At the first signs of a cold, start taking 100mg of beta-1,3/1,6-D-glucan, three times a day. Another option, make super-immunity soup such as the one included here, adding mushrooms that contain 1,3/1,6 beta-glucan. Sip throughout the day.
The use of Cordyceps dates back to traditional Tibetan and Chinese medicines. Cordyceps is known in Chinese medicine as a powerful lung tonic.
It fortifies the Qi circulation in the lungs and is especially useful for someone who is prone to bronchitis, wheezing or coughing. Cordyceps has been shown to increase respiratory capacity.
Take 1000 mg capsules twice a day as a means to strengthen your defenses. Cordyceps may also be prepared as a decoction by adding to boiling water, then simmering for 10 to 15 minutes.
1 yellow onion
2 large organic carrots
2 stalks of organic celery
1 head of kale
30g dried or fresh shiitake mushrooms
30g dried astragalus root
1-2 tbsp chopped ginger
10 garlic cloves
1 bunch of cilantro
¼ cup olive oil
Ground black pepper
Wash and cut the vegetables. You may sauté the vegetables in a little sesame or olive oil, for extra browning and flavor. Wash mushrooms and astragalus root and place them into a medium saucepan. Add cold water and bring to a boil. Lower the heat, and cook uncovered for 40 minutes. Add sea salt and black pepper to taste.
 Du X, Chen X, Zhao B, et al. Astragalus polysaccharides enhance the humoral and cellular immune responses of hepatitis B surface antigen vaccination through inhibiting the expression of transforming growth factor β and the frequency of regulatory T cells. FEMS Immunol Med Microbiol. 2011 Nov;63(2):228-35.
 Qun L, Luo Q, Zhang ZY, et al. Effects of astragalus on IL-2/IL-2R system in patients with maintained hemodialysis. Clin Nephrol. 1999 Nov;52(5):333-4.
 Miura, NN; Ohno N, Aketagawa J, Tamura H, Tanaka S, Yadomae T (January 1996). "Blood clearance of (1->3)-beta-D-glucan in MRL lpr/lpr mice". FEMS immunology and medical microbiology (England: Blackwell Publishing) 13 (1): 51-57.
 Vetvicka, V; Dvorak B, Vetvickova J, Richter J, Krizan J, Sima P, Yvin JC (2007-03-10). "Orally administered marine (1->3)-beta-D-glucan Phycarine stimulates both humoral and cellular immunity". International journal of biological macromolecules (England: Butterworth-Heinemann) 40 (4): 291-298.
 Babineau, TJ; Marcello P, Swails W, Kenler A, Bistrian B, Forse RA (November 1994). "Randomized phase I/II trial of a macrophage-specific immunomodulator (PGG-glucan) in high-risk surgical patients". Annals of surgery 220 (5): 601-609.
 Babineau, TJ; Hackford A, Kenler A, Bistrian B, Forse RA, Fairchild PG, Heard S, Keroack M, Caushaj P, Benotti P (November 1994). "A phase II multicenter, double-blind, randomized, placebo-controlled study of three dosages of an immunomodulator (PGG-glucan) in high-risk surgical patients". Archives of surgery 129 (11): 1204-1210.
 Dellinger, EP; Babineau TJ, Bleicher P, Kaiser AB, Seibert GB, Postier RG, Vogel SB, Norman J, Kaufman D, Galandiuk S, Condon RE (September 1999). "Effect of PGG-glucan on the rate of serious postoperative infection or death observed after high-risk gastrointestinal operations. Betafectin Gastrointestinal Study Group". Archives of surgery 134 (9): 977-983.
 Vetvicka, V; Terayama K, Mandeville R, Brousseau P, Kournikakis B, Ostroff G (2002). "Pilot Study: Orally-Administered Yeast β1,3-glucan Prophylactically Protects Against Anthrax Infection and Cancer in Mice" (PDF). Journal of the American Nutraceutical Association (Birmingham, AL : The Association) 5 (2): 5-9.
 Zhang J, et al. Effect of polysaccharide from cultured Cordyceps sinensis on immune function and anti-oxidation activity of mice exposed to (60)Co. Int Immunopharmacol. 2011 Dec;11(12):2251-7. Epub 2011 Oct 11.