Is green tea an immune booster?

Based on recent clinical findings, immune booster may be another health benefit to add to green tea’s extensive research portfolio. Although green tea is most commonly recognized as an important antioxidant, researchers have begun to focus on its potential to influence immune health. Read on to learn more about green tea and immunity.

Brewing up natural immune defense

Interestingly, emerging scientific research suggests that green tea and several of its components may help the body get ready to fight battle with environmental culprits. Initial research experiments in test tube and animal studies found that green tea may function in several ways to influence immunity. Scientists reported that green tea or its components may: 1) stimulate the production of various immune cells; 2) fend off bacteria and viruses; and 3) promote the production of various substances that help support immune function.^1-6

Further experimental research uncovered that L-theanine, an amino acid component of green tea, is broken down in the body to another compound that stimulates the production of important immune cells.^7,8 What’s more, the natural immune defense of immune cells from regular tea drinkers (ie, 6 small cups daily) was found to be 5 times faster than those of coffee drinkers. Because coffee drinking had no effect on the immune cells, researchers propose that tea’s unique chemical components are responsible for the potential immune cell boost that was recorded.⁸

Can supplements offer the same benefit as brewed tea?

While the findings thus far are encouraging, additional research evaluating the potential immune benefit of green tea supplements in humans is needed to determine what dosage may support immunity. In the meantime, the first clue to a potential benefit from green tea supplements comes from a recent well-controlled study from the University of Florida. Researchers examined a proprietary supplement containing L-theanine, green tea extract (standardized to contain 50% polyphenols and 45% EGCG) and rooibos tea extract. Compared to individuals taking a placebo (inactive supplement), the green tea supplement group faired significantly better during the cold weather season from January to May.⁹ In addition, researchers recorded a significant 28% increase in a specific type of immune cell from the green tea group compared to the same immune cells analyzed from subjects taking placebo. The immune cells from the green tea group also secreted 26% more interferon gamma, a substance that supports a healthy immune response.

Natrol offers the following products that you can use to boost your intake of L-theanine, polyphenols and EGCG, the active constituents of green tea that are being studied for immune health benefits.

• Natrol® Green Tea 500 mg: A guaranteed potency extract that provides 50% polyphenols and 25% catechins, including EGCG. Take 1-2 capsules daily.
• Laci Le Beau® Green Tea: All natural green tea leaf is a healthy beverage choice each day. Drink one or more cups daily.
• Natrol® L-theanine: Contains 150 mg of L-theanine in two tablets and has been studied for its relaxing qualities. Take 2 tablets daily.

References

1. Stoner GD, Mukhtar H. Polyphenols as cancer chemopreventive agents. J Cell Biochem. 1995;22:169-180.
2. Hamilton-Miller JM. Antimicrobial properties of tea (Camellia sinensis L.). Antimicrob Agents Chemother. 1995;39:2375-2377.
3. Zvetkova E, Wirleitner B, Tram NT, et al. Aqueous extracts of Crinum latifolium (L.) and Camellia sinensis show immunomodulatory properties in human peripheral blood mononuclear cells. Int Immunopharmacol. 2001;1:2143-2150.
4. Zhu M, Gong Y, Yang Z, et al. Green tea and its major components ameliorate immune dysfunction in mice bearing Lewis lung carcinoma and treated with the carcinogen NNK. Nutr Cancer. 1999;35:64-72.
5. Cheng S, Ding L, Zhen Y, et al. Progress in studies on the antimutagenicity and anticarcinogenicity of green tea epicatechins. Chin Med Sci J. 1991;6:233-238.
6. Song JM, Lee KH, Seong BL. Antiviral effect of catechins in green tea on influenza virus.
   Antiviral Res. 2005;68:66-74.
7. Bukowski JF, Morita CT, Brenner MB. Human gd T cells recognize alkylamines derived from microbes, edible plants, and tea: implications for innate immunity. Immunity. 1999;11:57-65.
8. Kamath AB, Wang L, Das H, et al. Antigens in tea-beverage prime human Vgamma 2Vdelta 2 T cells in vitro and in vivo for memory and nonmemory antibacterial cytokine responses. Proc Natl Acad Sci USA. 2003;100:6009-6014.
9. Rowe CA, Nantz MP, Bukowski JF, et al. Specific formulation of Camellia sinensis prevents cold and flu symptoms and enhances T cell function: A randomized, double-blind, placebo-controlled study. J Am Coll Nutr. 2007;26:445-452.

What supplements should I consider to support immune health during training?

While regular, moderate exercise seems to help boost immunity.¹ research has shown that intense training can weaken the immune defense. More than 90 minutes of high-intensity endurance exercise can make you susceptible to illness for up to 72 hours after the exercise session.² This is particularly important for those who compete in longer events such as marathons or triathlons. To help prime the body’s immune defense, consider these tried-and-true immune boosters.

Start with the basics – a daily vitamin C supplement. Busy schedules make it difficult to get enough of this essential immune-promoting vitamin from food alone. This is especially true if your lifestyle includes habits that increase your need for extra antioxidant protection such as regular exercise, high stress, living or working in an urban area, excessive sun exposure, or smoking. Meet your body’s needs by eating at least two servings of vitamin C-rich fruits and vegetables every day and taking a daily vitamin C supplement such as Natrol® Easy-C® 500 mg with Bioflavonoids to help bridge the gap between what your foods provide and what your body demands.^†

Nourish your gut with probiotics – every day. Your gut is a natural barrier against the external environment and your body’s primary immune organ. In fact, the intestines contain the largest pool of immune cells in the human body, known as the gut-associated lymphatic tissue or GALT. So, nourishing your gut is essential to your immune health. Taking a daily probiotic supplement, such as Natrol® Biobeads® Acidophilus Complex will fuel your body with a regular, concentrated source of the type of beneficial bacteria that experts recommend for optimal gut—and immune—health.^3†

Add targeted support. If you’re lifestyle includes regular, intense exercise, consider targeted immune support with Prolab® Glutamine Powder 1,000 gm. Glutamine is the most abundant amino acid in the skeletal muscle and is heavily metabolized under intense training conditions. Supplementing with glutamine can help maximize recovery after intense training by promoting energy repletion,⁴ maintaining a healthy immune system⁵ and maximizing your body’s buffering capacity against acid build-up.^6†

References

1. Silveira EM, Rodrigues MF, Krause MS, et al. Acute exercise stimulates macrophage function: possible role of NF-kappaB pathways. Cell Biochem Funct. 2007;25(1):63-73. PMID: 16906627

2. Nieman DC. Risk of Upper Respiratory Tract Infection in Athletes: An Epidemiologic and Immunologic Perspective.J Athl Train. 1997;32(4):344-349. PMID: 16558471

3. Reid G, Jass J, Sebulsky MT, McCormick JK. Potential uses of probiotics in clinical practice. Clin Microbiol Rev. 2003;16(4):658-672. PMID: 14557292

4. Tapiero H, Mathe G, Couvreur P, Tew KD. II. Glutamine and glutamate. Biomed Pharmacother.

2002;56(9):446-457. PMID: 12481981

5. Castell LM, Newsholme EA. The effects of oral glutamine supplementation on athletes after prolonged,

exhaustive exercise. Nutrition. 1997;13(7-8):738-742. PMID: 9263279

6. Marwood S, Bowtell JL. Effects of glutamine and hyperoxia on pulmonary oxygen uptake and muscle

deoxygenation kinetics. Eur J Appl Physiol. 2007;99(2):149-161. PMID: 17115180

† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.