Researchers from the Harvard School of Public Health explored how different protein sources affect sleep, highlighting that higher intake of plant-based protein may influence sleep patterns in meaningful ways. The study results were published in the European Journal of Clinical Nutrition (EJCN), adding to a growing body of evidence about diet and sleep health.
The analysis used data from a large and diverse participant pool, including information from 14,796 men and more than 83,000 women. Scientists gathered detailed dietary records and assessments of sleep quality to examine potential connections between protein consumption and nightly rest. A majority of participants—more than 65 percent—reported achieving seven to eight hours of sleep per night, providing a substantial baseline for evaluating nutrient effects on sleep duration and quality.
Across the overall sample, researchers found no straightforward link between total protein intake and sleep quality. Yet deeper statistical analysis revealed that protein sourced from plants was associated with fewer awakenings during the night and improved sleep efficiency for some individuals. Foods rich in plant protein include legumes, whole grains, seeds, and nuts, which may contribute to steadier sleep patterns through favorable effects on satiety, glycemic responses, and nutrient balance.
In contrast, the consumption of red meat and poultry, whether processed or unprocessed, showed an association with reduced sleep quality during the night in this study. The absence of similar effects for fish suggests different fatty acid profiles could play a role in sleep architecture. The researchers note that meats with higher fat content might shorten deep sleep stages, while leaner protein sources appear less disruptive to restorative sleep phases.
These findings align with broader scientific understanding that sleep quality supports immune function, partly by influencing growth hormone dynamics and other restorative processes. Improved sleep has been linked to enhanced immune regulation, which helps the body maintain resilience against infections and stressors over time. The study adds a nuanced perspective by pointing to plant-based protein as a potential factor in nighttime rest for some populations, alongside the known benefits of adequate sleep for immune health. [Citation: Harvard School of Public Health study; EJCN publication]