Dietary Interventions for Sleep Health: Multi‐Population and Mendelian Randomization Evidence on Sleep Outcomes and Disorders

Sleep disorders represent major public health concerns with significant health consequences. While diet shows promise as a modifiable intervention, the differential effects of established dietary patterns on specific sleep phenotypes and the contributions of specific food groups remains unclear. Therefore, this study investigated how three established dietary patterns relate to distinct sleep outcomes, and further explored the contributions of specific food components. We combined four decades of data and analyzed 9040 US adults from NHANES with sampling weights. Five sleep outcomes were examined in relation to dietary pattern adherence, quantified through averaged 24-h recall data from two consecutive days: including self-reported sleep duration, sufficiency, OSA, daytime sleepiness, and stop breathing. For international validation, we used the Global Dietary Database (62 countries) linked to country-level sleep apnea prevalence (191 countries). Cohort analysis employed the Chinese Longitudinal Healthy Longevity Survey (<i>n</i> = 6885). Causal associations between dietary components and sleep phenotypes were investigated using two-sample Mendelian randomization with genome-wide association summary statistics. Our results demonstrated that greater the Mediterranean Diet (MED) adherence was associated with longer sleep duration (<i>β</i> = 0.06, 95% CI: 0.03-0.10, <i>p</i> < 0.001) and sufficient sleep (OR = 1.10, 95% CI: 1.04-1.15, <i>p</i> < 0.001). Notably, dietary Approaches to Stop Hypertension (DASH) adherence offered the strongest protection against daytime sleepiness (OR = 0.89, 95% CI: 0.85-0.93, <i>p</i> < 0.001) and breathing cessation episodes (OR = 0.91, 95% CI: 0.85-0.96, <i>p</i> = 0.001). The Alternative Healthy Eating Index (AHEI) demonstrated balanced associations with improved sleep sufficiency (OR = 1.006, <i>p</i> < 0.05), reduced daytime sleepiness (OR = 0.995, <i>p</i> < 0.05), and fewer breathing episodes (OR = 0.989, <i>p</i> < 0.01). Furthermore, food-component-level analyses revealed consistent protective associations from legumes, nuts, and whole grains, while vegetables, fruits, meats, and SSBs showed variable effects-findings supported by both multi-database analyses and Mendelian randomization. Importantly, MR further demonstrated specific causal associations for fruits and vegetables: pears and strong vegetable preferences protected against short sleep, while cabbage, grapefruit, and melon causally increased sleep disorder risk. Additionally, processed meats causally increased OSA and snoring risk, with food processing degree emerging as a critical causal determinant. In conclusion, this study makes three main contributions. First, we provide a direct comparison of multiple dietary patterns (MED, DASH, AHE) across diverse sleep phenotypes. Second, we identify specific protective food components, with genetic causal evidence supporting their effects on sleep. Third, we integrate multi-national datasets to validate findings across diverse populations, substantially enhancing generalizability. Collectively, these findings support evidence-based dietary interventions for sleep health improvement.