Examine publishes rigorous, unbiased analysis of the latest and most important nutrition and supplementation studies each month, available to all Examine Members. Click here to learn more or log in.
Study under review: Omega-3 fatty acids for depression in adults
Introduction
Depression is the leading cause of disability worldwide, with an estimated 350 million people suffering from this mood disorder. Major depressive disorder (MDD) is a type of depression defined as a state of extreme unhappiness and inability to feel pleasure lasting at least two weeks. Figure 1 shows a breakdown of major depression in the US.
Source: SAMHSA, NIMH.
MDD can be very debilitating, has a high rate of recurrence, and often requires a complex mix of treatments. Comprehensive approaches to treating this affective disorder may include lifestyle interventions, therapy sessions, and the use of medications. In more difficult cases, electroconvulsive therapy, where electrical currents are sent through the brain, can be used to alleviate the symptoms of depression[1].
Increasingly, studies have examined the use of omega-3 polyunsaturated fatty acids (n-3) to treat depression. A link between n-3s and depression was suggested after the recognition of a population-wide reduction in Western dietary intakes of omega-3s[2] being correlated with[3] an increase in rates of depression. Some randomized controlled trials have shown benefits for symptoms of MDD[4] among those who supplemented with n-3s.
The positive effects of n-3s on depression are thought to occur as a result of alterations to the cell membrane, cell to cell communication, and on inflammatory processes and neurotransmitter activity. These processes[5] have all been implicated in the pathology of MDD[6].
However, not all investigations[7] have reported beneficial effects and previous meta-analyses have found considerable variability[8] among studies. The present study is the fourth update to the Cochrane Collaboration’s review on omega-3 fatty acids for depression. To help reduce the variability seen in other reviews, this meta-analysis focuses solely on MDD in adults, not taking into account other types of depressive disorders or younger populations. The objective of this review was to assess the effects of n-3s versus a comparator (e.g. a placebo or standard antidepressant treatment). To do this, the authors pool the results from multiple intervention studies and statistically analyze the data to see if there was a positive, negative, or neutral overall result.
Depression affects over 350 million people worldwide. Major depressive disorder (MDD) is defined as a state of extreme unhappiness and an inability to feel pleasure lasting at least two weeks. This meta-analysis examines the efficacy of n-3s versus placebo or standard depression treatment to alleviate the symptoms of MDD in adults.
Who and what was studied?
What were the findings?
What does the study really tell us?
The big picture
Frequently Asked Questions
What should I know?
Other Articles in Issue #15 (January 2016)
-
DASH plus fat equals ...
The DASH diet is one of the most studied diets of all time, and was specifically formulated to curb chronic disease. But will DASH still do it’s thing if you add extra fat each day?
-
Wine and dine with diabetes
For some, wine is a daily or weekly indulgence. As those with type 2 diabetes must pay extra attention to the blood sugar and lipid impact of what they consume, this trial puts red and white wine to the test.
-
Better living through cherry juice
Cherries and berries (the former is not a type of the latter, by the way) have increasingly shown cognitive benefits. This trial specifically explores cherries for Alzheimer’s disease.
-
Interview: Victoria Prince, MD, PhD
Victoria Prince is passionate about ancestral health and evolutionary medicine, and has a particular interest in dietary fats and the role they play in health and disease, especially liver disease. She writes at principleintopractice.com.
-
The chocolate fountain of youth
Cocoa contains high levels of beneficial phytochemicals called “flavanols”, which may provide a variety of health benefits. This randomized trial tested cocoa for the specific purpose of wrinkle reduction and other skin-related improvements.
-
Beyond ‘eat less, move more’: treating obesity in 2016
By Spencer Nadolsky, DO
-
A calorie is a calorie ... or is it?
Obesity research typically focus on what you eat, but less frequently touches on when you should eat it. Since animal models have shown strong results for meal timing, this study looked at potential weight-related benefits of eating earlier in humans.
-
A bit of D for CVD
Vitamin D is touted for pretty much every health condition out there. While observational evidence has strongly linked optimal vitamin D levels to cardiovascular disease, the trial evidence has been more mixed. This trial attempts to strengthen that literature base.
-
Your probiotic may be lying to you
Take a gander at a probiotic bottle label and you may be astounded at the number of live bacteria, as well as the variety these supplements contain. But the labels may not be entirely accurate
