Does sugar kill brain cells

Answer 1

Mostly by its absence. Brain cells run on glucose, which provides energy for them -- as well as for the rest of the body.

Eating excessive refined (white) sugar and refined fructose (corn syrup) can lead to insulin resistance, a precursor for diabetes and a component of Metabolic Syndrome. The high blood sugar associated with Diabetes -- which, oddly, means that the brain is not getting enough glucose (it is failing to pass from the blood to the cells where it is needed) could result in some brain damage. However, the other causes of death from diabetes far exceed any from damage to brain cells.

See the link below for more on diabetes and Metabolic Syndrome -- especially if you have a bit of a belly.

Answer 2

Glucose is the main fuel used by the brain. It can't really function without it (it can use molecules known as ketones, but it prefers to use glucose). Glucose is one of the few substances which can cross the blood-brain barrier. Our blood glucose is tightly regulated between 4-6 mmol l-1 partly to ensure that our brain has a continuous supply of this sugar. However, that doesn't mean that people should eat loads of sugary foods. Most glucose in the blood should come from the breakdown of complex carbohydrates such as starch and indeed the body can find all the glucose it needs from these forms of carbs. The body can also make glucose when supplies are low from certain amino acids (from protein) and fatty acids; a process known as gluconeogenesis. Humans needn't ever eat any sugary foods at all. Sugar won't damage brain cells, but there is some argument that eating refined sugar causes rapid and severe fluctuations in the blood sugar level and this may cause intense highs and dramatic lows, which may leave a person feeling drained and not as intellectually astute. The effect won't be permanent though.