(RxWiki News) You know the feeling: it's the afternoon slump, and that soda or candy bar is just the ticket to give you that sugar rush for an extra burst of energy and alertness.
But not so fast. New research shows that it is not sugar, but protein, that keeps us awake and alert.
"Protein bars offer an energy boost."
Dr. Denis Burdakov of the University of Cambridge led a research team that studied the effects of different nutrients on the cells that are responsible for keeping us awake and burning calories. The cells, called hypothalamic orexin/hypocretin (orx/hcrt) neurons, secrete a stimulant called orexin/hypocretin in the brain. Increase this stimulant, and one is likely to be alert and full of energy.
Reduced activity in the orexin cells, on the other hand, results in narcolepsy and has also been linked to weight gain.
Dr. Burdakov and his team used mice, highlighting the orexin cells in their brains with genetically targeted fluorescence. The researchers then introduced different nutrients and tracked the orexin cell impulses. Amino acid mixtures, similar to egg white protein, stimulated the cells, while glucose (found in sugar) blocked them.
But the protein had an even bigger effect; the amino acids actually stopped glucose from blocking the cells. In other words, protein negated the effect of sugar on these "wakefulness" brain cells.
“What is exciting is to have a rational way to ‘tune’ select brain cells to be more or less active by deciding what food to eat,” Dr. Burdakov said. The findings may help explain why protein meals can make people feel more alert than meals with carbohydrates.
Dr. Burdakov added that to combat obesity and insomnia in today’s society, more information is needed on how diet affects sleep and appetite cells. The findings were published in the November 2011 issue of the journal Neuron.