Several large population studies have linked low levels of omega-3 fatty acids – or high levels of omega-6 fatty acids – with risk of depression.
Unfortunately, this generally unhealthful “omega imbalance” typifies the average American’s diet and blood fat profile.
The results of clinical trials testing omega-3s against depression have been mixed, possibly because different trials have used different kinds of omega-3s at different doses, in patients with varying degrees of depression.
And it goes without saying that a person’s individual genetics may also influence the effects that a nutrient or drug exerts (or doesn’t) on their mood health.
But what about omega-3s’ potential to ease the related mood disorder called anxiety?
Omega-3s and anxiety: Prior evidence points to potential benefits
More recently, a Spanish study found that the participants reporting the highest omega-3 intake were least likely to show signs of depression, anxiety, or stress … see “Omega-3 Mood Benefits Get More Backing.”
Now, researchers from Ohio State University report the positive outcomes of a clinical trial testing the potential calming effects of omega-3 fish oil in people who were not diagnosed with anxiety.
In brief, the results showed that a daily dose of 2.5 grams (2,500mg) of fish-source omega-3s may reduce symptoms of anxiety by about 20 percent (one-fifth).
Ohio State study sees reduced anxiety in med students
An Ohio State research team recruited medical students to participate in a small but rigorous – randomized, placebo-controlled, double-blind – pilot clinical trial funded by the National Institutes of Health (Kiecolt-Glaser JK et al. 2011).
The 68 prospective physicians took either placebo capsules or fish oil capsules containing 2,085 mg of omega-3 EPA and 348 mg of omega-3 DHA, for three months.
They provided blood samples and completed a battery of mental tests designed to measure stress, anxiety, and depression, at the outset of the trial and every two weeks.
The researchers expected to detect significant signs of anxiety, due to the tough medical school curriculum … but unplanned changes made the students’ schedules less stressful than expected.
As lead author Janice Kiecolt-Glaser, Ph.D., told a reporter for Psych Central, “These students weren’t really stressed. They were actually sleeping well throughout this period, so we didn’t get the stress effect we had expected” (PC 2011).
Nonetheless, the psychological tests still detected substantial reductions in anxiety among the students.
Compared with the placebo group, the fish oil group showed two major benefits:
Importantly, as the authors wrote, “The reduction in anxiety symptoms associated with omega-3 supplementation provides the first evidence that omega-3s may have potential [anti-anxiety] benefits for individuals without an anxiety disorder diagnosis … [and] can reduce inflammation and anxiety even among healthy young adults.” (Kiecolt-Glaser JK et al. 2011)
A reduction in chronic inflammation is highly desirable, since it is a major causative or exacerbating factor in most major degenerative conditions – from cardiovascular disease to dementia – and is also linked to anxiety.
The study authors explained the link between anxiety and inflammation: “Pro-inflammatory cytokines promote secretion of corticotropin-releasing hormone (CRH), a primary gateway to hormonal stress responses; CRH also stimulates the amygdala, a key brain region for fear and anxiety. Accordingly, alterations [increases] in inflammation could also influence anxiety.” (Kiecolt-Glaser JK et al. 2011)
Their blood analyses showed a significant, 14 percent drop in blood levels of a pro-inflammatory cytokine (messenger protein) called IL-6 in the omega-3 group, compared to the placebo group.
And, the fish oil group developed lower omega-6/omega-3 ratios over the course of the study, which correlated with their reducing anxiety scores and with drops in production of another pro-inflammatory cytokine, called TNF-alpha.
We should note that the mental tests showed no effect on symptoms of depression … which is unsurprising since the students did not suffer from depression.
In contrast, folks in high-pressure environments like medical school will periodically experience more worry than normal … which means that an efficacious drug or nutrient could reduce anxiety signs, even in people who do not have a diagnosed anxiety disorder.
The Ohio trial’s findings do not prove that fish oil capsules are potent, fast-acting “chill pills” that can treat serious anxiety … though hope and more research are clearly warranted by the positive indications of this and prior studies.
That said, the new results suggest that supplemental omega-3s – or fish-rich diets – may help us all feel a bit calmer overall.
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