Why Drinking Tea is Smart
For most people, sipping a cup of tea is a soothing experience. The mere transference of heat from mug to hand is often enough to promote relaxation, to say nothing of the herbaceous vapors rising up invitingly from the brim. Certainly, taking a few moments to quietly enjoy a cup of tea is a welcome distraction from all that tasks us and it would be reasonable to assume that the body and brain respond accordingly. That assumption is correct, but there’s more to it than that – much more. Recent research shows that chemical compounds in tea, namely a water-soluble acid called theanine, have an effect on the brain that triggers a reduction of anxiety and depression while improving memory and cognitive function.
Theanine, also known as L-theanine, appears to work with the caffeine component in tea to increase alertness, attention to detail and the ability to multitask with less risk of distraction. Studies show that supplementation with theanine and caffeine results in improved cognitive test scores after 30 and 90 minutes compared to placebo or caffeine alone. In a double-blind placebo-controlled study published in the Journal of Medicinal Food in 2011, a team of Korean scientists found that subjects with mild cognitive impairment who supplemented with 1,680 mg of theanine for 16 weeks performed better on word and memory tests than their placebo-taking counterparts. (A cup of black tea delivers approximately 20 mg theanine.)
Both human and mouse study models exhibit signs of reduced anixiety and depression with theanine therapy, including people with schizophrenia or schizoaffective disorder. In addition to stress-reducing and antioxidant properties, researchers believe that theanine may inhibit the accumulation of amyloid beta, a protein fragment associated with plaque formation in the brain that leads to Alzheimer's disease.
References & Suggested Reading
Kimura K, Ozeki M, Juneja LR, Ohira H. "L-Theanine reduces psychological and physiological stress responses." Biol Psychol . 2007;74(1):39-45
Giesbrecht T, Rycroft JA, Rowson MJ, De Bruin EA. "The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness." Nutr Neurosci. 2010 Dec;13(6):283-90
Einöther SJ, Martens VE, Rycroft JA, De Bruin EA. "L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness. Appetite." 2010;54(2):406-409
Owen GN, Parnell H, De Bruin EA, Rycroft JA. "The combined effects of L-theanine and caffeine on cognitive performance and mood." Nutr Neurosci . 2008;11(4):193-198
Park SK, Jung IC, Lee WK, et al. "A combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled study." J Med Food. 2011;14(4):334-343
Yin C, Gou L, Liu Y, Yin X, Zhang L, Jia G, Zhuang X. "Antidepressant-like effects of L-theanine in the forced swim and tail suspension tests in mice." Phytother Res. 2011 Nov;25(11):1636-9. doi: 10.1002/ptr.3456
Ritsner MS, Miodownik C, Ratner Y, et al. "L-theanine relieves positive, activation, and anxiety symptoms in patients with schizophrenia and schizoaffective disorder: an 8-week, randomized, double-blind, placebo-controlled, 2-center study." J Clin Psychiatry. 2011;72(1):34-42
Matsumoto K, Yamada H, Takuma N, Niino H, Sagesaka YM. "Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: a randomized controlled trial." BMC Complement Altern Med. 2011 Feb 21;11:15
Unlike herbal teas, which are derived from the leaves, roots, bark, flowers and seeds of various plants, true tea comes from Camellia sinensis, a small evergreen shrub from Asia. Black, green and white teas all come from this plant, but have varying oxidation levels because they each undergo different degrees of fermentation. Green and white teas are the least processed.