Could a high-protein diet help give you a deeper sleep?

A diet rich in protein could help promote deeper sleep, if the findings of a study looking at flies and mice hold true in humans.

The study, published in Cell, shows that a protein-rich diet can make sleeping flies and mice less responsive to sensory inputs, specifically mechanical vibrations.

The investigators identified a signaling pathway through which information about dietary proteins is conveyed from the gut to the brain, to help suppress sensory arousal.

The study found that increased protein concentration in the gut leads to higher levels of a peptide, CCHa1, which enables the flies to sleep through stronger vibrations, whereas CCHa1 depletion from the gut causes easy awakenings even when the vibrations are weak.

Interestingly the CCHa1 pathway does not impact responsiveness to other types of disturbance, including temperature changes, demonstrating that different sensory inputs are dealt with through separate mechanisms during sleep.

Mice on a protein-rich diet are also harder to wake up

The investigators also tested whether a protein-rich diet would make mice harder to wake up when subjected to shaking, and found that the rodents who had been fed a protein-enriched diet were indeed deeper sleepers than their counterparts who had eaten a normal diet. In both cases the mice would wake up when the shaking was of high intensity, proving that there was no general sensory impairment of the mouse.

Interestingly, the enriched diet did not lead to an increase in the overall amount of sleep, rather it led to “better-consolidated” sleep, which the investigators defined as “longer bouts of sleep that were interrupted by fewer awakenings.”

According to the scientists the results make sense, given that when an animal’s needs are met they can devote time to sleeping, so having had good quality food - the protein-rich diet - means an animal is likely to sleep deeper.

Evolutionary basis for sleep signalling

The paper notes that given that sleep originated in the very earliest animals, which had rudimentary nervous systems, it is no surprise that parts of the core sleep regulatory system would use molecular signalling rather than relying on the nervous system. It concludes that while most investigation into sleep focuses on the nervous system, this research shows that a “more integrative approach taking into account not only the nervous system but also other organs is needed to solve some of the biggest mysteries in biology.”

An ancient idea in healthcare is that the digestive and nervous systems are fundamentally linked in terms of health and illness, an idea this study very much appears to support.