Consumption of oily fish may boost sleep quality, according to research published in Sleep Medicine.
Oily fish is a major source of long-chain omega-3 polyunsaturated fatty acids, which play a key role in the secretion of serotonin, as well as vitamin D, which has been found to be involved in the sleep-wake cycle.
In this study, researchers evaluated the effects of oily fish consumption on sleep quality in a population-based cohort of villagers from Atahualpa, Eduador.
In all, 677 participants aged ≥40 years were included in the study. Fifty-six percent were women, 64% had primary school education only, and 19% admitted alcohol ingestion ≥50 g/day. Mean oily fish consumption was 9.1 ± 5.6 servings per week (range 0-32); 4% consumed less than 2 servings and 35% consumed more than 10 servings per week. Poor sleep quality (PSQI score ≥6) was observed in 28% of participants (overall mean PSQI 4.5 ± 2.2). Cardiovascular risk factors, including smoking status, physical activity, BMI, fasting glucose, and cholesterol were also evaluated.
Overall, participants with poor sleep quality were older, less educated, and had worse physical activity level and fasting glucose levels than those with good sleep quality. Those with good sleep quality had consumed higher servings of oily fish (P=0.013); for every 10-serving increase, PSQI improved by 9.3% (95% CI 2-17%).
After adjusting for demographic and cardiovascular risks, a significant association was found between PSQI score and number of oily fish servings per week (β= –0.032, 95% CI –0.605 to –0.004, P=0.025).
The results of the study support the theory that oily fish consumption is associated with improved sleep quality. Even in participants who ingested more than the recommended amount of oily fish servings, increased dietary intake was associated with further improvement of sleep quality.