Abstract:
Previous research has suggested possible associations between dietary fat intake, obesity and sleep. In a mHypoE-37 neuron cell culture model, saturated fat was found to disrupt regulation of the Circadian Locomotor Output Cycles Kaput (CLOCK) gene (implicated in circadian rhythms) but the addition of docosahexaenoic acid (DHA) attenuated this disruption. DHA supplementation in children has yielded positive sleep outcomes, but there is a paucity of such data in adults. Therefore, the aim of this thesis was to determine the relationship between total dietary fat, omega-3 fatty acids, and DHA intake with sleep quality among healthy adults. Data were from an observational study, aimed to phenotype healthy adults, conducted at the National Institutes of Health (NIH) Clinical Center (Bethesda, MD). Adults (n=226) completed 7 day food records to determine dietary intake of total fat and long chain fatty acids. The Pittsburgh Sleep Quality Index (PSQI) assessed overall sleep quality as well as seven subcomponents: (1) subjective sleep quality, (2) sleep latency, (3) sleep duration, (4) habitual sleep efficiency, (5) sleep disturbances, (6) use of sleeping medication, and (7) daytime dysfunction. Medication, demographics and anthropometric measurements were obtained from medical records. Univariate regression analyses explored predictors of total PSQI score and its subcomponents. Medication use, Body Mass Index (BMI) and sex were consistently related to sleep quality. Adjusting for these covariates, percent energy from fat, omega-3 (g/1000 g) intake, and DHA (g/1000 g) intake were not significant predictors of overall sleep quality. However, when examining PSQI subcomponent scores in adjusted analyses, omega-3 intake was a statistically significant predictor of sleep latency (Adj. R2=0.050, β=-0.340, p=0.042). While total omega-3 intake was not associated with overall sleep quality, this thesis suggests the potential role for omega-3 in shortening sleep latency. As short sleep is associated with chronic illness and weight gain, nutritional interventions aimed at increasing sleep duration may lead to improvements in overall health. Thus, further investigation examining the association between omega-3 fatty acid and sleep quality is warranted.
