A new study from Norway suggests that people who consume salmon, a food containing some of the highest amounts of vitamin D and omega-3 fatty acids, seem to experience reduced anxiety compared to people who consumed alternative meals.
The interventional study measured the heart rate (HR), the heart rate variability (HRV), the level anxiety, as well as blood concentrations of vitamin D and omega-3 fatty acids of 95 male criminal inpatients who consumed Atlantic salmon or an alternative meal (e.g., chicken, pork or beef) three times per week for 23 weeks (1). The study results showed that, compared to the participants who ate meat, the fish consumers showed significant improvements in both HR and HRV as well as reductions in (temporary) anxiety about a situation or an event. In addition, they had increased blood levels of vitamin D, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
The researchers commented that the beneficial effect of fish consumption on HRV could be due to the participants’ improved vitamin D status – a key factor in the regulation of serotonin, which in turn is very important for the regulation of HRV (2). HRV is regarded as an essential underlying biological mechanism involved in anxiety and emotion-regulation (3). If this is solely a vitamin D effect, a routine vitamin D supplementation could be adequate, they said. However, the beneficial effect of Atlantic salmon consumption may also be due to increased intakes of marine omega-3 fatty acids, selenium, iodine, vitamin B12 and their multiple mechanisms.