by Dr. Andrew Weil: Many nutrition experts contend that pure water is the most healthful thirst quencher…

While that’s certainly an excellent choice – and far better than fruit juices or soda, both of which can spike blood sugar and lead to weight gain – I believe there’s an even better one: green tea.

Green tea comes from the lightly steamed leaves of the Camellia sinensis plant. It was first brewed in China during the reign of Emperor Shennong in 2737 BC. Long revered in many cultures and traditions throughout Asia, its popularity has soared in the West – particularly the U.S. – in the past two decades.

That’s fortunate, as research into this ancient beverage has validated its longstanding reputation for supporting physical and mental health. Scientific inquiries report that green tea:

1. contains antioxidants, including polyphenols such as epigallocatechin gallate (EGCG), which can powerfully quench damaging “free radicals,” metabolic byproducts that are chemically reactive and can damage cells. According to a study published in the European Journal of Clinical Nutrition, the polyphenols found in green tea provide six times the radical-quenching potential of those found in black tea.
2. supports cardiovascular and metabolic health. According to a study published in the Journal of the American College of Nutrition, researchers found subjects consuming five or more cups of green tea per day were less likely to develop hypertension (high blood pressure) and diabetes, or die of cardiovascular disease or stroke. Researchers also found in animal studies that EGCG improved heart health by preventing “overload-induced cardiac hypertrophy” – or thickening of the heart muscles.
3. helps to prevent fatty buildup in arteries, according to a 2013 study published in the Journal of Biological Chemistry. The investigation found EGCG from green tea may reduce cholesterol levels, ultimately assisting in lowering the risk of cardiovascular disease.
4. can increase energy and mental focus. Green tea contains a small amount of caffeine, which a 2008 study in Nutrition Bulletin found can improve mood, cognitive function and physical performance. Green tea contains less caffeine than does coffee, and provides L-theanine, an amino acid shown to promote a state of calm awareness. Result: green tea provides the benefits of alertness associated with caffeine without the “jittery” feeling often experienced as a side effect of coffee.
5. quickly calms and relaxes. L-theanine exhibits anti-anxiety effects by increasing dopamine levels in the brain, and also appears to decrease blood pressure. A study published in Trends in Food Science & Technology found green tea produces relaxing effects without drowsiness only 40 minutes after ingestion.
6. facilitates the burning of body fat. Green tea promotes the body’s ability to burn fat through thermogenesis and fat oxidation. A study published in The American Journal of Clinical Nutrition found the combination of polyphenols and caffeine from an extract of green tea resulted in a “significant increase” of energy expenditure compared to placebo.
7. may help prevent skin damage and cancer. An animal study published inMutation Research/Fundamental and Molecular Mechanisms of Mutagenesisfound green tea appears to protect against skin papillomas and tumors induced by UVA and UVB light. The study also reported that sun-induced inflammatory changes were “slightly lowered” by tea consumption.
8. may improve bone health. A study published in Nutrition Research found the bioactive components of green tea may help decrease the risk of fracture by improving bone mineral density.
9. may lower the risk of certain types of cancer. Studies have examined green tea’s potential role in lowering risks of breast, ovarian, bladder, esophageal, and prostate cancers. More studies are needed, but research so far is promising.
10. improves insulin sensitivity and may help protect against diabetes, as well as against rapid rises and subsequent crashes in blood sugar levels that lead to fatigue, irritability, and food cravings. A study in Annals of Internal Medicinefound consumption of green tea (as well as black tea and coffee), was associated with a reduced risk of type 2 diabetes.

Bottom line: green tea is a delicious, healthy drink that should be part of your daily diet. Its health benefits are best realized when it’s served hot and with a wedge of lemon, but it can be enjoyed chilled or even iced. There are many varieties of green tea, so experiment until you find one you like!