The flu season has arrived—make sure you're ready! Nutritional support has been shown to interfere with the pathogenic processes of influenza. Overall aging is associated with dysregulated immune function and inflammatory responses, though individually this can vary significantly. Good nutritional status can play a major role in avoiding a steep immune decline. There are four primary nutrients I recommend you test prior to flu season:
- Vitamin D
- Probiotics
- Selenium
- Vitamin E
Vitamin D
Vitamin D acts as an immune system modulator. It prevents excessive expression of inflammatory cytokines, increases the "oxidative burst" potential of macrophages, and stimulates the expression of potent anti-microbial peptides in epithelial cells lining the respiratory tract where they play a major role in protecting the lung from infection. Not surprisingly vitamin D deficiency has been found to predispose children to respiratory infections. Certain populations, such as the elderly and those who are overweight, have higher rates of low vitamin D levels. Research suggests that 1 in 3 women and 1 in 2 men with a Body Mass Index (BMI) greater than or equal to 40 are vitamin D deficient. (Anticancer Research, September 1, 2009 vol. 29 no. 9 3713-3720.)
Probiotics
The bulk of your immune system is located in your gut, so it’s not a stretch that probiotics have proven effective at warding off cold and flu viruses. Research indicates that probiotics may reduce the incidence and the severity of symptoms in the common cold. This may be due in part to stimulated cellular immunity. In a randomized, double-blind intervention study, over 400 healthy adults were given vitamins plus minerals, with or without the probiotics lactobacilli and bifidobacteria. Those who received the probiotics had a significantly shortened duration of illness, by almost 2 days, and reduction in severity of symptoms. There were also larger increases in T suppressor cell counts and in T helper cell counts. (Vaccine. 2006 Nov 10;24(44-46):6670-4. / Int J Clin Pharmacol Ther. 2005 Jul;43(7):318-26.)
Selenium
Selenium deficiencies have been shown to enhance the virulence or progression of some viral infections, like the flu. The immune-enhancing properties of selenium improve cellular immune response through an increased production of interferon gamma and other cytokines, an increase in T helper cells, and improved activation and proliferation of B-lymphocytes. Animal research has shown that a mild strain of influenza increased its virulence when given to selenium-deficient mice, compared to selenium-replete mice. (Nutr.,2003 May;133(5 Suppl 1):1463S-7S.). Research has demonstrated that selenium deficiency has a significant impact on the morphology and influenza-induced host defense responses in human airway epithelial cells. (Free Radic Biol Med. 2007 Jun 15;42(12):1826-37)
Vitamin E
Antioxidant supplementation is thought to improve immunity. Antioxidants include vitamin C, vitamin E, and bioflavonoids which have been shown to help reduce the incidence or severity of the flu. Vitamin E is important for normal function of immune cells, and is thought to reduce age-related defects in T cells. Animal studies have found vitamin E to improve immune functions that may be related to improved resistance to influenza and better clearance of the virus. Vitamin E is also associated with a reduced rate of upper respiratory tract infection in the elderly. (Immunol Rev. 2005 Jun;205:269-84)
So what are you to do?
First and foremost, determine your levels are for vitamin D and E, selenium and predominant bacteria BEFORE flu season is in full swing, and supplement accordingly.
P.S. - Check out what Canada is doing to examine vitamin d for swine flu protection.
