Coffee first entered human lives and veins over 600 years ago. Now we consume an average of almost two kilos per person each year – sometimes with very specific preferences about blends and preparation methods. How much you drink is influenced by genes acting on your brain's reward system and caffeine metabolism . Coffee can raise your blood pressure in the short term, especially if you don't usually drink it or if you already have high blood pressure. But this doesn't mean you need to cut out