Is Green Tea Bad For Your Health?

Green tea is an herbal beverage made from the Camellia sinensis plant that contains useful biological compounds called polyphenols. The numerous health benefits of green tea are largely due to its high content of polyphenols. It has been used for centuries in Asian nations, suggesting green tea would be safe to use. However, like anything else, green tea has some undesirable properties. Consult your doctor to see if green tea is safe for you.

Anticancer Properties

Green tea is a major source of antioxidant polyphenols called catechins, which display antitumor properties by acting as free radical scavengers. Polyphenolic antioxidants help neutralize free radicals, which would otherwise bind to the nucleic acids of cells, introducing carcinogens that can cause mutations leading to cancer cell formation. Doctors at the Memorial Sloan-Kettering Cancer Center believe that green tea polyphenols might reduce the incidence of free radical damage to nucleic acids, reducing the risk of cancer.

Periodontal Disease

In modern culture, green tea supplements remain a natural means of combating bacterial infections. They also have considerable effect against oral bacterial growth, preventing the adherence of gram-negative bacteria, such as Streptococcus mutans, Porphyromonas gingivalis and Streptococcus sobrinus, which are involved in periodontal disease -- an infection or inflammation of the gums and bone supporting the teeth. These virulent bacteria have been found to produce multiple enzymes that damage and degrade tooth enamel, thus causing dental caries.

Serious Side Effects

The side effects of green are related to the caffeine in the tea. Higher doses of green tea may cause tachycardia and tachypnea, which means fast breathing. Tachycardia is an abnormally fast heart rate, which, if left untreated, can result in a sharp drop in blood pressure leading to heart failure and death. Decaffeinated tea is recommended for those suffering from these serious heart conditions.

Pregnancy and Lactation

The safety of green tea-containing supplements during pregnancy and lactation is not clear. Green tea caffeine passes into nursing infants in breast milk, causing sleep disorders. It also inhibits the absorption of iron into the body, which can lead to microcytic anemia. Limit your caffeine intake to 300 mg per day during your pregnancy and when you are breastfeeding, according to the University of Illinois at Urbana-Champaign.