Consumed for thousands of years in China, green tea is said to aid with stress reduction and weight management. All types of tea—green, black and oolong—are produced from the Camellia sinensis plant using different methods. Fresh leaves from the plant are steamed to produce green tea, while the leaves of black tea and oolong involve fermentation.
Green tea contains B vitamins, folate, manganese, potassium, magnesium, caffeine, and other antioxidants, like catechins.
Here are some reasons why a cup of green tea a day may actually keep the doctor away.
1. It can prevent heart disease.
Just one cup of green tea a day could lower the risk of heart disease and premature death, according to Japanese researchers.
In a study of more than 90,000 people aged 40 to 69 over four years, researchers found that the more green tea people drank, the less likely they were to die from heart disease, stroke, and respiratory disease.
Women who drank just one cup a day had a 10 per cent lower risk of dying early, but this rose to 17 per cent if they drank five or more cups daily.
The study, published in the Annals of Epidemiology in 2015, also saw a similar trend in men.
2. It's anti-allergenic.
Green tea may help seasonal allergy sufferers, as it's been proven to be anti-allergenic; a specific compound, epigallocatechin gallate (EGCG), appears to be the most potent. A 2007 study published in the journal Cytotechnology found the tea polyphenol can reduce pollen allergies. Quercetin, a naturally occurring flavonol in tea, can also alleviate a histamine response.
3. It helps lower blood pressure.
A survey in 2014 from previously published studies looked at the whether drinking green tea could help lower blood pressure. There was evidence of a modest reduction in people with high blood pressure who consumed green tea. However, whether this would lead to clinically significant results, such as preventing the onset of heart disease or stroke, is unclear.
4. It reduces cholesterol.
A review of 11 studies in 2013 involving over 800 people found daily consumption of green and black tea (as a drink or a capsule) could help lower cholesterol and blood pressure thanks to the catechins it contains. Another review found drinking green tea enriched with catechins led to a small reduction in cholesterol, a main cause of heart disease and stroke. However, it's still not clear from the evidence how much green tea we'd need to drink daily to see a positive effect on our health.
5. It prevents tooth decay
Drinking black tea and coffee has been given a bad reputation for its staining effect on your teeth. A study in 2014 looked at how effective a green tea mouthwash was in preventing tooth decay compared with the more commonly used antibacterial mouthwash chlorhexidine. The results suggested they were equally effective, though green tea mouthwash was cheaper.
6. It relaxes you.
Theanine is an amino acid naturally found in tea leaves and is thought to provide a relaxing and tranquilizing effect, though you may have to drink six cups to really feel any impact.