A recent study published in the Journal of Epidemiology & Community Health has suggested that eating a lot of fish may help reduce the risk of depression. Major depression is one of the most common mental disorders, with most families affected by a loved one or acquaintance at some point during their lives. It is also commonly misunderstood and misdiagnosed; or there is no treatment sought at all. The National Institute of Mental Health defines depression as:
- A period of two weeks or longer during which there is either depressed mood or loss of interest or pleasure, and at least four other symptoms that reflect a change in functioning, such as problems with sleep, eating, energy, concentration, and self-image.
As recent as 2013 the National Institute of Mental Health reported an estimated 15.7 million adults aged 18 or older in the U.S. had at least one major depressive episode in the past year – or 6.7% of all U.S. adults (NIMH, 2013).
According to the World Health Organization, major depression is associated with the heaviest burden of disability among mental and behavioral disorders (WHO, 2010). Major depression accounts for:
- 7 percent of all U.S. disability-adjusted life years
- 3 percent of all U.S. years lived with disability
- Depression is projected to become the 2nd leading cause of ill health by 2020.
Given the global impact of the disease, with 350 million people affected worldwide, researchers conduct ongoing studies into causes and treatment. While many previous studies have examined the potential impact of diet on mental health, findings have been inconsistent. For this study, researchers in the Department of Epidemiology and Health Statistics at The Medical College of Qingdao University in China pooled data from past studies published from 2001-2014 to analyze the strength of the evidence linking fish consumption and depression risk – the studies included 16 articles with 26 studies of 150,278 participants. Ten studies were from Europe, 7 from North America as well as Asia, Oceania and South America (ScienceDaily, 2015).
After reviewing all the combined data, a “significant” association emerged between participants eating the most fish and a 17% reduction in depression risk – but only in the European studies (ScienceDaily, 2015). The connection between a high fish diet and mental health was equal among men and women
Researchers acknowledge that future studies are needed to understand further the cause for this association, and if it varies by the type of fish eaten – there may be biological explanations, or eating a lot of fish may be an indicator of an overall healthier diet.