Tea - Second most drank substance.
Studies of potential benefits have been done in regards to: anti-cancer properties, increasing metabolic rate, possible anti-diabetes effect, boosts mental alertness, boosts immune system, lowers chances of congnitive impairment, lowers stress hormone levels, effects on HIV, EGCG-specific mechanism, oxalates, effects on inflammatory bowel disease (IBD), effects on bad breath, effects on obstructive sleep apnea-related brain deficits, effects on bacterial and fungal infections, anti-venom effects.
Potential drawbacks: effects of fluroide: According to Schuld, fluoride could reduce the anti-cancer properties of tea, or even possibly cause cancer at continued toxic levels of the mineral. For instance, Schuld references a 1998 study which found positive correlation between colon cancer and tea intake. The high fluoride content could also cause neurological and renal damage, especially in the presence of aluminum. Additionally, the high fluoride content could cause osteoporosis, arthritis, skeletal fluorosis and other bone disorders.
effects associated with caffeine: This finding suggests that tea does not have a diuretic effect unless the amount of tea consumed at one sitting contains more than 250-300mg of caffeine, equivalent to between 5 and 6 cups of tea.
Oxalates: Tea contains oxalate, overconsumption of which can cause kidney damage, as well as soak up free calcium in the body; other minerals could be soaked up as well. The bioavailability of oxalate from tea is low and because of this a negative effect requires large amounts of tea.
Tannin: It has been suggested that the chemical known as tannin may increase the risk of nasal and esophogeal cancer, with some studies having found that tea drinking may in fact be negatively associated with risk of esophageal cancer.
Rooibos is becoming more popular in Western countries particularly among health-conscious consumers, due to its high level of antioxidents such as aspalathin and nothofagin, its lack of caffeine, and its low tannin levels compared to fully oxidized black tea or unoxidized green tea leaves.
Rooibos is purported to assist with nervous tension, allergies and digestive problems.
Traditional medicinal uses of rooibos in South Africa include alleviating infantile colic, allergies, asthma and dermatological problems. -Taken from wikipedia
Green tea has been claimed to be helpful for: atherosclerosis, LDL cholesterol, cancer, inflammatory bowel disease, diabetes, liver disease, weight loss, neurodegenerative diseases, and even halitosis.
Peppermint: In 2007, Italian investigators reported that 75% of the patients in their study who took peppermint oil capsules for four weeks had a major reduction in irritable bowel syndrome (IBS) symptoms, compared with just 38% of those who took a placebo.
Ginseng: Both American and Panax (Asian) ginseng roots are taken orally as adaptogens, aphrodisiacs, nourishing stimulants, and in the treatment of type II diabetes, including sexual dysfunction in men. The root is most often available in dried form, either whole or sliced. Ginseng leaf, although not as highly prized, is sometimes also used; as with the root it is most often available in dried form.
Ginger: In Burma, ginger and a local sweetener made from palm tree juice (Htan nyat) are boiled together and taken to prevent the flu.
In China, a drink made with sliced ginger cooked in sweetened water or a cola is used as a folk medicine for the common cold.
In the Congo, ginger is crushed and mixed with mango tree sap to make tangawisi juice, which is considered as a universal panacea.
In India, ginger is applied as a paste to the temples to relieve headache and consumed when suffering from the common cold, people use ginger for making tea, in food etc.
In Indonesia, a type of ginger known as Jahe is used as a herbal preparation to reduce fatigue, reducing "winds" in the blood, prevent and cure rheumatism and controlling poor dietary habits.
In the Philippines a traditional health drink called "salabat" is made for breakfast by boiling chopped ginger and adding sugar; it is considered good for a sore throat.
In the United States, ginger is used to prevent motion and morning sickness. It is recognized as safe by the Food and Drug Administration and is sold as an unregulated dietary supplement.