There Are Many Health Benefits From Drinking Tea
Black, white, green, oolong and teas all come from the Camelia sinensis plant and only differ in how the leaves are dried and prepared. For example, for black tea, the leaves are allowed to oxidise in which the enzymes react with oxygen. Green tea leaves, however, are not oxidised but steamed and pan-fried right after drying.
While green tea extract allows you to consume higher amounts of EGCG (the plant compound epigallocatechin gallate) than you would get from drinking tea, other benefits from green tea are impressive. It may:
- Improve heart, liver and brain health, bone mineral density and weight control and support healthy blood pressure
- Reduce oxidative stress
- Support exercise performance, exercise recovery and enhancement of antioxidant protection
According to the Journal of Indian Society of Periodontology, green tea may also have positive effects on:
Weight loss — EGCG prevents the breakdown of norepinephrine thus causing a rise in metabolism.
Antiaging — Antioxidants in green tea protect the skin from the harmful effects of free radicals, which cause wrinkling and skin ageing.
Immunity — Polyphenols and flavonoids found in green tea help boost your immune system.
Cardiovascular disease — Green tea helps prevent heart disease and stroke.
Liver disease — Men who drink more than 10 cups of green tea per day are less likely to develop disorders of the liver.
Cancer — EGCG has been shown to inhibit angiogenesis of tumor cells by stopping the production of angiogenic compounds.
Arthritis — Green tea can help prevent and reduce the risk of rheumatoid arthritis.
Diabetes — Green tea improves lipid and glucose metabolism, prevents sudden increase in blood sugar levels and balances your metabolic rate.
Alzheimer's — EGCG decreases production of beta-amyloid, a protein that forms the plaques that clog the brains of Alzheimer's victims.
Parkinson's — Antioxidants in green tea help prevent against cell damage in the brain, which could cause Parkinson's, and thus help prevent it.
Cold and flu — EGCG, a powerful catechin antioxidant found in green and white teas, can directly kill bacteria and viruses.
Asthma — Theophylline in green tea relaxes the muscles that support the bronchial tubes, reducing the severity of asthma.
Stress — L-theanine, which is a kind of amino acid in green tea, can help to relieve stress and anxiety.
Food poisoning — Catechin found in green tea can kill bacteria that causes food poisoning and kills the toxins produced by those bacteria.
Human immunodeficiency virus — With human immunodeficiency virus (HIV), the EGCG acts as a block to the HIV transport protein on the host cell.
Dental caries — The effects of green tea extract on caries inhibition in hamsters and on acid resistance of human tooth enamel have been suggested by both in vivo and in vitro studies.
Periodontal health — The inhibitory effects of catechin contained in green tea on periodontal pathogens may provide the basis for beneficial effect of daily intake of green tea on periodontal health.
Halitosis — Halitosis is caused mainly by volatile sulphur compounds such as H2S and CH3SH produced in the oral cavity. Tea polyphenols have been shown to have antimicrobial and deodorant effects.
Tea Lessens Anxiety and Improves Cognition
Green tea may reduce such negative psychological states like anxiety and improve cognition. According to a meta-analysis in the journal Phytomedicine:
"The reviewed studies presented evidence that green tea influences psychopathological symptoms (e.g. reduction of anxiety), cognition (e.g. benefits in memory and attention) and brain function (e.g. activation of working memory seen in functional MRI)."
The positive cognitive effects of tea are especially important for the elderly, who may be facing difficult situations and cognitive challenges. While the beneficial effects could come from the relaxing context in which the tea is consumed — preparing the brew, using a favourite cup and sitting down to enjoy a break from the world's troubles — they also likely have a physical base. According to the journal Phytomedicine:
"The effects of green tea cannot be attributed to a single constituent of the beverage. This is exemplified in the finding that beneficial green tea effects on cognition are observed under the combined influence of both caffeine and l-theanine, whereas separate administration of either substance was found to have a lesser impact."
Tea Reduces Inflammation and May Fight Cancer
Scientific studies have found that ingredients in tea can reduce inflammation and plaque formation. According to the Harvard Heart Letter:
"'Tea is a good source of compounds known as catechins and epicatechins, which are thought to be responsible for tea's beneficial health effects.'
These compounds belong to a group of plant chemicals called flavonoids. Research suggests that flavonoids help quell inflammation, and that in turn may reduce plaque buildup inside arteries. Green tea has slightly higher amounts of these chemicals than black tea."
Green tea may also help to fight prostate cancer, the second most frequently diagnosed cancer in men. In one study of prostate cancer, the journal Medicine, Baltimore, wrote:
"There was a trend of reduced incidence of prostate cancer with each 1 cup/day increase of green tea … Our novel data demonstrated that higher green tea consumption was linearly reduced PCa risk with more than 7 cups/day and green tea catechins were effective for preventing PCa."
Green tea also may be a tool against liver cancer. A 2017 meta-analysis in the journal Nutrition and Cancer found a significant inverse dose-response association between green tea drinking and liver cancer risk. That inverse association increased with years of green tea drinking and when four cups a day of green tea were consumed. According to the journal:
"We also found a trend that the incidence of liver cancer was reduced with the increasing years of green tea intake (significance at >20 yr). A significant dose-response association was found between green tea drinking and liver cancer risk.
The downward trend was most obvious when the consumption of green tea increased up to about 4 cups/day. The results showed that the increasing green tea intake may have a preventive effect against liver cancer."