Green tea has been proven to provide health benefits، but taking it in high doses especially in supplement form might cause even more problem، as the Technical Times said. A middle-aged man from Dallas، Texas was admitted to the hospital and in need of liver transplant. His doctors suspect that over-the-counter green tea supplements، which he has been taking for three months، was the cause of his liver injury. "It was shocking because I'd only heard about the benefits،" the patient، named Jim McCants، told the BBC. "I'd not heard about any problems." McCants started taking green tea extract in supplement form in order to aid in his drive to become healthier. He started eating healthier and regularly exercising، but the promise of antioxidant benefits from the supplements drew him in. However، one day، his wife noticed that his face has turned yellow. He was advised by his hepatologist to immediately have a liver transplant within a week after he had been admitted to the hospital. Like any other type of food، green tea، when consumed in excessive amounts، can cause serious problems. A previous study by the U.S. National Institute of Health confirmed that a large intake of green tea، when taken as a drink or from a supplement، is linked to acute liver failure.