Depressed? You may want to consider adding some extra fish to your diet.
A new study found that European men and women who ate more fish tended to have a lower risk of depression.
"Considering its public health impacts, there is increasing interest in exploring modifiable lifestyle factors to prevent depression," wrote lead study author Christopher J. L. Murray, MD, DPhil, a professor of global health at the University of Washington, and colleagues. "There are several studies concerning how changes in diet affects depression, but the findings were inconclusive."
Depression is a mood disorder that causes a persistent feeling of sadness and loss of interest. Different from usual mood fluctuations or short-lived emotional responses to everyday life, depression can be a serious health condition.
According to the World Health Organization (WHO), depression affects more than 350 million people worldwide. It is also projected to be the second most common cause of poor health by 2020 — right behind heart disease, according to WHO.
For this study, Dr. Murray and team pooled data from multiple studies published between 2001 and 2014 to look at the potential effects of fish intake on depression risk.
These researchers included 26 studies involving 150,278 patients worldwide — 10 studies from Europe, seven from North America and nine from Asia, the South Pacific and South America.
Studies related to postpartum depression (depression that occurs after childbirth) or depression during pregnancy were not included in this analysis.
Depression was defined as a medical diagnosis, starting regular use of antidepressant drugs or scoring high on depression rating scales.
Those who ate more fish were 17 percent less likely to be at risk of depression than those who ate less fish. This was only true in Europe, however.
No such link was found in the rest of the world.
European men saw a larger decreased risk of depression (at 20 percent) than European women (at 16 percent).
According to Dr. Murray and team, due to the observational nature of this study, no conclusive evidence can be given.
However, there are some biological aspects of fish that may support these findings. For instance, omega-3 fatty acids found in fish have been found to influence serotonin and dopamine (two neurotransmitters linked to depression) levels in the brain.
This study was published Sept. 10 in the Journal of Epidemiology & Community Health.
No funding sources or conflicts of interest were disclosed.