Omega-3 And Fish Oil In Depression

Omega 3 fatty acids and fish oil has been featured in medical journals when it comes to the area of depression.

It has done so both in the risk of depression in the general population as well as in the treatment of patients who are on anti-depressant medications.

Here are some of these studies:

Omega 3 And The Risk Of Depression

In the Omega 3 Fatty Acids symposium in New York on May 21, 2005, Joseph Hibbeln MD presented findings about the links between omega 3’s and our mental health.

Nations with the highest omega 3 fatty acid intakes have the lowest levels of major depression, bipolar disorder, and homicide according to epidemiological studies.

For example, Japan has the lowest levels of depression (0.12% of population)], Iceland the lowest levels of bipolar depression, and Hong Kong with the lowest homicide levels. These countries also have the fish oil consumption with 730 mg/day, 1000 mg/day and 730mg/day of EPA and DHA respectively, compared to the US, where consumption of DHA and EPA on average is about 180 mg/day.

The author speculated that 750 mg/day is possibly adequate, and 1000 mg/day of omega-3 fatty acids is clearly adequate for lowering risk of psychiatric disorders, in his recommendations at the conference.

He also mentioned the importance of balancing the ratio between omega 3’s and omega 6’s as both of these fatty acids compete for metabolism in the body. That is, keeping dietary omega 3 fatty acid intake constant, while avoiding excessive intake of omega 6 fatty acids.

Reference:

• Hibbeln JR. Omega-3 fatty acids and Mental Health. Presented at the omega-3 fatty acids: Recommendations for therapeutics and prevention symposium. May 21, 2005. New York.

Adding Omega 3 Fatty Acids To Standard Anti-Depressant Therapy

In a 4 week, double-blind placebo controlled trial in 2002, it was found that adding omega 3 fatty acids to antidepressant therapy, resulted in significantly improved depressive symptoms.

Specifically 2 g/day of eicosapentaenoic acid (E-EPA), one of the fatty acids found in fish oil, was added to the antidepressant therapy. It was found that the reduction in the Hamilton depression scale score in patients receiving the omega-3 fatty acids was 12.4 points, compared with 1.6 in patients receiving placebo.

The effect was seen within 2 weeks of taking the fish oil, similar in timing to the effect of medications for depression.

There has been epidemiological studies on the relationship between fish oil consumption and risk of depression, but this study was one of the first placebo controlled studies which has been done which has involved adding in fish oil and seeing the effect on patients with depression and who are already on standard antidepressant therapy.

Study Details:

• Nemets B, Stahl Z, Belmaker RH. Am J Psychiatry. Mar 2002; 159(3):477-9

Fish Oil On Patients Still Depressed Despite Being On Anti-Depressant Medications

In another pacebo controlled study published in 2002, 46 patients who were still depressed despite the fact that they were on antidepressant medications, shown an improvement with 1g of EPA (a component of fish oil) per day.

Patients were either given 1g, 2g, 4g of the omega 3 or a placebo. The group given 1g per day did the best. 69% of the 1g/day group, compared to 25% of the placebo group had a 50% reduction on the Hamilton Depression Rating Scale score.

In terms of which symptoms were affected, the study found that all 20 items of the Beck Depression Inventory improved, with “strong beneficial effects on items rating depression, anxiety, sleep, lassitude, libido, and suicidality.” It was found that the improvements were seen equally in both patient and physician based assessments.

The other advantage of this treatment group was that the treatment was generally well tolerated and there was a low drop out rate (12%) compared to the average drop out rates of “conventional” antidepressants (27-30%).

Further studies will no doubt emerge on the role of fish oil in treating depression as a result of this pioneering work.

Study Details:

• Peet M, Horrobin DF. A Dose-Ranging Study of the Effects of Ethyl-Eicosapentaenoate in Patients With Ongoing Depression Despite Apparently Adequate Treatment With Standard Drugs. Arch Gen Psychiatry. Oct 2002;59:913-919.

Risk Of Depression Related To Fish Intake In Finnish Study

In a Finnish study of 3402 people in 2001, it as found that there was a correlation between fish consumption and lower rate of depressive symptoms among women.

The survey looked at the amount of fish consumption compared to depressive symptoms as estimated with the 21-item Beck Depression Inventory (BDI). The results were statistically significant in women, with the likelihood of mild to severe depression was 40% higher in women who were infrequent fish consumers (less than once a week) (OR=1.40, 95% CI=1.11 to 1.78, p<.01) than among frequent consumers (more than once a week).

The authors commented that this population study should encourage more research into the effect of omega 3 fatty acids on depression.

Though the mechanism by which fish oils affect mood is unknown, they commented that perhaps it is related to serotonin turnover in the brain, as it has been shown that 5-hydroxy-indoleacetic acid, a metabolite of serotonin is associated with high plasma levels of omega-3 fatty acids among healthy subjects.

Study Details:

• Tanskanen A, Hibbeln JR, Tuomilehto J, et al. Fish Consumption and Depressive Symptoms in the General Population in Finland. Psychiatric Services. 52:529-531, April 2001.