A STEAMING cup of tea, the relaxing drink of choice for millions in countries such as Britain and China, could help ward off the effects of Alzheimer’s disease, scientists said today.Laboratory tests found that regular cups of green and black tea inhibit the activity of certain enzymes in the brain which bring on Alzheimer’s, a form of generative dementia that affects an estimated 10 million people worldwide. The research by the Medicinal Plant Research Centre at Newcastle University, north-east England, is published in academic journal Phytotherapy Research.