What is the primary energy source for human brain function?

The primary energy source for human brain function is glucose. The brain is highly dependent on glucose as its key fuel for maintaining its high energy demands, which account for about 20% of the body's total energy expenditure at rest. Unlike other tissues in the body that can utilize fatty acids or other energy sources when necessary, the brain primarily relies on glucose for proper function, particularly during periods of intense activity or stress.

Glucose is utilized in cellular respiration to produce adenosine triphosphate (ATP), the energy currency of the cell. Without sufficient glucose, brain function can be impaired, leading to symptoms such as confusion, dizziness, and cognitive deficits. This reliance on glucose underscores the importance of maintaining balanced blood sugar levels for optimal brain health and cognitive performance.

While fatty acids, proteins, and amino acids can serve as energy sources under specific circumstances, they are not the primary fuel for the brain. The metabolic pathways for fatty acids and proteins are not as efficient or directly utilized by the brain as glucose is.