Six or more cups a day increase your risk of heart disease by 22 per cent, researchers reckon. This seems to be the tipping point for coffee drinking, after which your blood pressure will rise. Hypertension, or high blood pressure, is one cause of cardiovascular disease, still the world's major killer.
Drinking that amount every day will certainly make you jittery or irritable—and that can also be the tell-tale sign to stop, say researchers from the University of South Australia.
Some may not experience these reactions even after drinking six cups—and that can depend on our genetic ability to process caffeine—but that shouldn't mask the fact that that really is the limit, the researchers say.
They based their recommendations on a survey of 347,000 people aged between 37 and 73 whose coffee drinking and health were monitored. The researchers weren't trying to assess the health benefits of coffee drinking but were looking for the safe limits to daily consumption.
"Knowing the limits of what's good for you and what's not is imperative. As with many things, it's all about moderation: overindulge and your health will pay for it," said researcher Prof Elina Hypponen.