Study Says Drinking 25 Cups br of Coffee a Day Is Safe The report was conducted by scientists at Queen Mary University of London. The first group drank less than cup of coffee a day, while the second had between one and three. The final was comprised of those who br drank more than three, with some br even claiming up to 25 cups a day. MRI heart scans were then given br to all subjects in the study. As were tests br concerning pulse waves. Factors like age, weight, blood pressure and diet were weighed into the results. Results went on to show that drinking br a ton of coffee versus just a little didbr not affect human arteries. Even those with 25 cups a day did not show br themselves to be more susceptible to stiffness. One of the scientists, Kenneth Fung, says the study br is not recommending you drink that much coffee.