Liver damage, anaemia: ‘Healthy’ green tea can make you ill
While green tea comes with an array of benefits, it is also associated with a number of side effects. Experts shed light on some of them.Updated: Feb 09, 2016, 09:25 IST
Three months ago, a 16-year-old girl in UK, complained of dizziness, nausea, stomach and joint pain to her general physician. Two days later, her condition worsened. Reportedly, the medical team she was referred to believed that she was suffering from acute hepatitis, a swelling or inflammation of the liver.
It was quite a surprising turnaround of events as she had not consumed alcohol, taken drugs, or any over-the-counter prescription medication. However, she recalled, that she had consumed three cups of green tea, every day, for a period of three months. The doctors believed that green tea was the causative agent for her condition, as her health began to improve immediately after she stopped drinking green tea.
Although green tea has been lauded for its antioxidant and immune-boosting properties, and its health benefits documented in several studies, a number of doctors feel that when consumed in excess, it can have serious repercussions. “Anything consumed in excess can cause trouble. The same applies to green tea. It is a common notion that one can have as much green tea as they like. However, that is not true. Green tea can have mild to serious side effects, that range from gastric irritation and pain, to hepatic abnormalities,” says Dr Amrapali Patil, nutritionist.
Dr Suvidha Raibole, nutritionist, agrees, saying, “There are scientific studies that indicate that abnormally high amount of green tea consumption can cause oxidative stress and liver toxicity.”
Experts share that green tea can worsen a number of conditions. Those suffering from the following should not consume more than two cups in a day:
Green tea contains tannins. They prevent the absorption of iron in the body. A study done in 2001, which was published in the American Journal of Clinical Nutrition, reports that green tea extract reduces the absorption of iron by 25%. Iron is required for haemoglobin synthesis in humans. Patients suffering from anaemia suffer from decreased haemoglobin levels. Therefore, green tea should be avoided by anaemic patients.
Dehydration and Constipation
Caffeine is a diuretic, and causes dehydration. People suffering from constipation should avoid consuming green tea due to its caffeine content. And, if a person wishes to continue having green tea, he or she must drink a lot of water to stay hydrated, and prevent constipation.
Tannin, which is found in green tea, also reduces the absorption of folic acid, which plays an important role in preventing birth defects. As stated above, it also hinders the absorption of iron, which plays an important role during pregnancy.
Caffeine is known to increase anxiety and therefore, green tea should be avoided by people with anxiety disorders.
High amount of green tea intake has been found to cause liver damage, due to the extreme concentration of antioxidants and micronutrients.
There are clinical studies that state consuming green tea in moderation enhances bone mineral density and bone strength. However, drinking green tea in excess can actually lead to osteoporosis, since it tends to flush out the calcium from the body. Diabetes Caffeine in green tea can affect the control of blood glucose levels. A person who is consuming too much green tea might need to check these levels frequently, so as to adjust the dosage of anti-diabetic medication, which they are taking as per prescription.
The beverage also worsens glaucoma, as it increases the pressure in the eye within half an hour of its consumption.
High blood pressure
Caffeine in green tea can increase blood pressure, in those who are hypersensitive.
Irritable Bowel Syndrome
When consumed in large amounts, the caffeine content in green tea can worsen this condition.
(With inputs from Dr Amrapali Patil, nutritionist, Dr Suvidha Raibole, nutritionist, Alka Sharma, dietician, and Dr Behram Pardiwala, consultant, internal medicines)