Some say the brain is the most important organ in the human body. Who can argue with that? Without it, you would have no identity and no consciousness. Plus, your brain coordinates the function of every organ in your body, so you’d be lost without it. You want the gray and white matter in your brain to stay healthy. Sugar can negatively affect brain function short-term by causing a rapid rise and fall in blood sugar. In response to blood sugar swings, you might feel tired, anxious, lightheaded, dizzy, or have brain fog. But there are other negative effects of sugar on the brain. Animal studies show that animals that eat a diet high in sugar and fat have lower levels of a neurotrophin called brain-derived neurotropic factor (BDNF) that your brain needs for learning, memory, and to form new pathways and connections. Higher levels of BDNF are linked with better cognitive function and mental health. If you’re eating a lot of sugar, rethink it, since BDNF naturally falls as you get older, which may explain why cognitive function declines with age. Fortunately, aerobic exercise also boosts BDNF.