A fairly large amount of research has studied green tea and its components, because they “may contribute to a reduction in the risk of cardiovascular disease and some forms of cancer, as well as to the promotion of oral health and other physiological functions such as anti-hypertensive effect, body weight control, antibacterial and antivirasic activity, solar ultraviolet protection, bone mineral density increase, anti-fibrotic properties, and neuroprotective power”. (Link.) Even if green tea only reduces risks of these diseases by a small amount, it would still be a potent weapon against them precisely because it has such a broad spectrum of action. Much of the health effect of green tea and its extracts comes from a component called EGCG, a polyphenol and one of those “noxious dietary phytochemicals” that induces hormesis and causes an increase in cellular stress defense mechanisms, such as up-regulated antioxidant defenses and phase 2 enzymes, both of which are cancer-protective. While most of the research in this area has been done with green tea, there’s some evidence that black tea components may have equal power to effect favorable changes in health markers. Black and green tea are both made from the same plant, but the black version undergoes fermentation.
Another component of green tea has profound effects on cognition and memory, that component being the amino acid theanine. Theanine may protect against cognitive dysfunction and prevent oxidative stress related brain aging Especially in combination with caffeine, theanine improves mood and cognitive function. Theanine extends lifespan in C. elegans.
Green tea, green tea catechins, and epigallocatechin gallate (EGCG) have been demonstrated in cell culture and animal models of obesity to reduce adipocyte differentiation and proliferation, lipogenesis, fat mass, body weight, fat absorption, plasma levels of triglycerides, free fatty acids, cholesterol, glucose, insulin and leptin, as well as to increase beta-oxidation and thermogenesis. Adipose tissue, liver, intestine, and skeletal muscle are target organs of green tea, mediating its anti-obesity effects. Studies conducted with human subjects report reduced body weight and body fat, as well as increased fat oxidation and thermogenesis and thereby confirm findings in cell culture systems and animal models of obesity.
Looks like if you’re overweight you should start drinking green tea immediately, or perhaps get some green tea extract for a more potent dose. (This particular one contains only 16 mg caffeine, but when taking GTE, one should be cognizant of caffeine content, since adding it on to regular caffeine consumption means its addition could pack a wallop.) Theanine alone significantly reduced body fat in mice, and reduces feeding behavior in rats as well as lowering insulin levels.
I’ve only cited a handful of studies out of what must be hundreds. But virtually every one that I’ve looked at has confirmed my own experience with it. A dose of 200 mg along with a cup of tea or coffee can put one into the zone of concentration, helping with tasks, such as writing, that require extended focus. Theanine also reduces stress levels noticeably. Since I spend a lot of time writing at a computer, theanine-induced increase in concentration is of real benefit.
See the Recommended Supplements page for a good brand of theanine at only about 22 cents a dose. Bulk theanine is even cheaper, and I’ll be adding that to the supplements page. Or buy theanine at Amazon.
See also Meditation in a Pill.