On Wednesday, scientists said that people who drink three to four cups of coffee a day are more likely to see health benefits than harm, experiencing lower risks of premature death and heart disease than those who abstain. The team found that coffee consumption was linked to lower risks of diabetes, liver disease, dementia and some cancers. Scientists said that three or four cups a day confer the greatest benefit, except for women who are pregnant or who have a higher risk of suffering fractures.