Did you know the Guinness Book of World Records no longer includes a record for the longest time spent without sleep? Guinness considered the record too dangerous and took it out. Why? Because going for prolonged periods without sleep can literally kill you - a human being can survive for four times as long without food as they can without sleep, about 10 days. So why is sleep so important? Getting a good night's sleep has a raft of health benefits that go far beyond banishing those black circles under your eyes. Improve your memory When you're learning a new skill, you can get so far with practice. But something magical happens when you sleep - your brain undergoes a process called consolidation and you'll strengthen the memory of those skills you learned while you were awake and perform better the next day. Cut your risk of a heart attack A 2010 study found higher levels of C-reactive protein, which can be linked to the risk of a heart attack, in people who got six or fewer hours of sleep a night. Not getting enough sleep is also linked to higher blood levels of the inflammatory proteins that can cause diabetes and arthritis. Pick up a paintbrush It's true, getting a good night's sleep can make you more creative. Your brain seems to consolidate the emotional components of a memory during sleep, spurring your urge to create. So pick up a paintbrush or start writing that book. Keep the weight off Sleep and metabolism are governed by the same centres in the brain, but dieters who are well rested lose more fat than dieters who aren't, who lose muscle instead. You'll also feel hungrier, the less sleep you get. Beat the blues Not getting enough sleep can lead to more than simple irritability - it can lead to depression too. A good night's sleep leads to emotional stability, keeping anxiety at bay. But whatever the health benefits, the key to a really good night's sleep is a great mattress. If yours is showing signs of wear, invest in a new one - your body will thank you for it!