Pu-erh tea (pronounced POO-air) is the most oxidized form of tea, often aged, and sometimes very expensive. Unlike other teas, which get stale over time, pu-erh can mellow and improve with age like fine wine. Some pu-erh teas are more than 50 years old, and rare pu-erh teas sell for many thousands of dollars in Asian specialty stores.
As for pu-erh tea benefits, because it is fully oxidized, pu-erh has a lower antioxidant content than white or green tea, but Chinese people credit it with many health benefits, especially promotion of weight loss, reduction of serum cholesterol, and cardiovascular protection. Not many scientific studies exist on pu-erh tea, so we don’t know how valid these health claims are. Some research suggests that pu-erh may help lower cholesterol and reduce heart disease risk, but this hasn’t been confirmed in humans. A Chinese study performed on rats and published in 2009 showed lowering of LDL (“bad”) cholesterol and triglyceride levels after the animals were fed a pu-erh tea extract, along with an increase in HDL (“good” cholesterol). We know that tea, in general, is protective against heart disease and cancer. It’s likely that pu-erh tea has similar effects.