If you fall, hit your head, and become unconscious, you are likely bruised and bleeding, even if you can’t see it. We now know that if you’re unconscious for more than an hour from a head injury, you have twice the risk of developing Alzheimer’s as those without such a history. After the bleeding stops and the swelling goes down following head trauma, you can still have scar tissue that may be involved in the future development of Alzheimer’s. Luckily, a product out there can help: the helmet. Always wear a helmet when riding a motorcycle, skateboarding, bicycling, rock climbing, playing hockey or football, or participating in any sport where you risk a fall. In a recent study, researchers found that bikers who wore helmets had a 52 percent lower risk of severe traumatic brain injury and a 44 percent lower risk of death than those not wearing helmets. Even if you think you’re a champion bicyclist, horse rider, or whatever, accidents can easily happen and wearing a helmet can help keep you from scrambling your brain.