A tea is alkaline—the opposite of acidic—when it contains a low concentration of hydrogen, a condition commonly known as a high pH. The ideal pH for good health is neither acidic nor alkaline, but between the two. Fortunately, as explains Stephanie Vangsness, a registered dietitian with the Dana-Farber Cancer Institute and Brigham and Women's Hospital, your body has a whole system set up to keep its pH balanced, even if you drink too much alkaline tea.
Fermentation is what distinguishes green tea from other teas. Green tea leaves aren't fermented and, as a result, the drink is high in antioxidants. They neutralize compounds called free radicals, which cause disease and cell death. According to the University of Maryland Medical Center, research shows that green tea may be helpful in controlling various health problems, including atherosclerosis, high cholesterol, diabetes and cancer.
Although dandelions are invasive plants, they also sprout brimming with health benefits. The Columbia University states on its website that 17th-century Europeans brought dandelions to North America as medicine. They used it to treat an array of problems, from fevers, boils and diarrhea to liver congestion and heartburn, among other conditions. All parts of the dandelion plant offer the same health benefits, and they can also all be brewed into a slightly bitter cup of tea.
Ginseng is not one single plant, but several species in the family known as Panax. In Asia, ginseng has been harvested for several thousand years for its medicinal value. Ginseng tea is also widely available at health food stores in the United States. According to MedlinePlus, a website of the National Institutes of Health, science has found good scientific evidence of ginseng's positive contributions to the treatment of heart conditions, high blood sugar, and type 2 diabetes, as well as to boosting your immune system.
Dr. Brent A. Bauer, an internist at the Mayo Clinic, describes kombucha as a cluster of bacteria and yeast that is mixed with sugar and either black or green tea and left to ferment. This yields kombucha tea, a substance containing vinegar and vitamin B. Possible health benefits of kombucha tea haven't been studied in any human trials. But since there have been reports of adverse reactions to this concoction, Dr. Bauer cautions against drinking this tea.