Increased intakes of fatty fish may improve sleep quality

According to a new study from Norway the consumption of fatty fish three times per week seems to have a positive impact on sleep in general and also on daily functioning.

The clinical study measured eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) concentrations in red blood cells and parameters of sleep (sleep onset latency, efficiency, sleep and wake time) as well as daily functioning of 95 men with sleep problems who consumed either Atlantic salmon or meat (portion size of 150 – 300 grams) three times per week for a period for 6 months (1). The study results showed that participants with regularly fish intake had higher red blood cell concentrations of EPA plus DHA, increased serum vitamin D levels and reported on an improved sleep quality, daily functioning and heart rate variability (HRV), compared to the control group.

The researchers commented that fatty fish is the major dietary source of omega-3 fatty acids and vitamin D, nutrients that have been suggested to play potential roles for prevention of sleep problems (2). Earlier stu- dies indicated that regular fish consumption seems to be associated with better cognitive control (related to HRV) in adults (3) and improved sleep quality in children, potentially linked to less learning problems (4). In addition, recent studies have reported about a possible relationship between optimal blood levels of vitamin D (60-80ng/ml) and better sleep quality as well as less sleep disturbances and sleepiness during the day (5). Further investigation is needed in order to gain more knowledge about the specific or exact underlying mechanisms responsible for the beneficial effects of fatty fish consumption.

1. Hansen A. L. et al. Fish consumption, sleep, daily functioning, and heart rate variability. J Clin Sleep Med. 2014; 10(5):567–575.
   
2. Peuhkuri K. et al. Diet promotes sleep duration and quality. Nutr Res. 2012; 32:309–319.
   
3. Hansen A. L. et al. Fish consumption and underlying mechanisms in self-regulation. Psychophysiology. 2012; 49:S121.
   
4. Montgomery P. et al. Fatty acids and sleep in UK children: Subjective and pilot objective sleep results from the DOLAB study – a randomised controlled trial. Journal of Sleep Research. Published online March 2014.
   
5. Gominak S. C. and Stumpf W. E. The world epidemic of sleep disorders is linked to vitamin D deficiency. Med Hypotheses. 2012; 79:132-135.