Green tea supplements, available in the form of capsule, liquid and powder form, contain concentrated extract of the plant Camellia sinensis. It is the same plant that is used to make green tea as well as black tea and oolong tea with the difference that the latter two involve the use of different processes. Supplements are taken for the many health benefits which range from aiding weight loss to lowering blood pressure and even preventing different types of cancer.
Benefits of taking green tea in the form of supplements are virtually the same as consuming brewed tea leaves. Many people, however, choose to take green tea supplements because they don’t like the taste of green tea but want to benefit from its consumption. Others decide for supplements rather than tea form also because these tend to contain only the most desirable ingredients while being removed most – if not all – of the unnecessary and potentially harmful ones, for example heavy metals. It is also possible to find supplements with reduced or zero caffeine content, which are especially popular with those with caffeine intolerance.
Besides for its distinct flavour, green tea is also consumed for a myriad of health benefits. The beverage – as well as its supplement alternative – is thought to help prevent, treat or manage a range of health problems including high and low blood pressure, diabetes, high cholesterol, Parkinson’s disease, depression, diarrhoea, osteoporosis and many others including some of the most serious illnesses like cancer. Green tea has also been shown to be very effective against genital warts but only in the form of a special ointment which is applied topically.
Both tea form and supplements of green tea have been suggested to be potentially effective against endometrial cancer, ovarian cancer, colon cancer, breast cancer, lung cancer, cervical cancer and many other types of this life-threatening disease. However, with exception of endometrial and ovarian cancers, which tend to be lower in women who regularly consume green tea, there is insufficient evidence to support the use of green tea for prevention/management of other types of cancer.
Despite its many health benefits, green tea can also cause unwanted side effects, especially if consumed in large doses over a long period of time. The plant contains caffeine, which despite being in lower quantities than in coffee, can cause caffeine-related side effects in sensitive individuals: headache, sleep difficulties, irritability, dizziness, diarrhoea, vomiting, tremor, confusion and convulsions. Furthermore, a recent study has also found that green tea contains a chemical which can cause liver damage if consumed in high amounts.
Except for individuals with intolerance or oversensitivity to caffeine, green tea – including the supplement form – are safe for most people when taken in moderate amounts. However, due to potential drug interaction, people who are taking medications – no matter if being prescription or over-the-counter - are advised to consult their doctor before taking any supplements, including those containing green tea extract. It is also recommended to seek medical advice if being pregnant or having a medical condition prior taking green tea supplements, capsules, liquid or powder or increasing consumption of the tea form.