Globally, it is known that HIV-infected pregnant women are prone to depressive symptoms. Research evidence also suggests that nutrient deficiencies may enhance the depressive illness, and that fish oil omega-3 fatty acids may alleviate the depressive symptoms.

The aim of this study was to assess the effect of fish oil omega-3 eicosapentaenoic acid-rich supplements on depressive symptoms among HIV-seropositive pregnant women.

A randomized double-blinded controlled trial with two parallel groups was conducted. The intervention group received fish oil omega-3 of 3.17 g (eicosapentaenoic acid = 2.15 g; docosahexaenoic acid = 1.02 g) per day for 8 weeks, while the control group received soybean oil for a similar period.

Participants were HIV-seropositive pregnant women who were enrolled in the prevention of mother-to-child transmission programs and attending antenatal clinics at selected Nairobi city county's health facilities. Recruitment was done from health records of HIV-infected pregnant women.

Data analysis followed per-protocol analysis. Participants who completed the 8-week trial were included in the analysis of covariance statistical model with omega-3 as the main effect. The covariates in the change in BDI-II depressive symptom score outcome were baseline characteristics and nutrient adequacy.

Mild depressive symptoms

282 participants were recruited 109 randomized to fish oil, and 107 to soybean oil. Completion rate was 86/109 (78.9%) and 96/107 (89.7%) respectively. At the end of the week-8 of follow up most participants in both arms had mild depressive symptoms 82/86 (95.3%) in the Fish oil group and 94/96 (97.9%) in the Soybean oil group. The difference in effect between the intervention and control group was not statistically significant (1.01 (95% CI – 0.58 to 2.60), p = 0.21).

Fish oil omega-3 with a daily dosage of 3.17 g (eicosapentaenoic acid = 2.15 g; docosahexaenoic acid = 1.02 g) appears to provide no added benefit in reduction of the symptoms of depression in HIV-infected pregnant women.

The research hypothesis for the study was derived from the evidence that omega-3 can alleviate symptoms of depression. If omega-3 EPA fatty acid is the most important compound in alleviating depressive symptoms, then depressed individuals taking fish oil omega-3 supplements should experience a change in the severity of their depressive symptom condition.

A 50.0% reduction in depressive symptom scores after 8 weeks of supplementation with fish oil (EPA = 2.2 g/day; DHA = 1.2 g/day) had been earlier reported. Sources of omega-3 fatty acids have also influenced the designing of studies on fish oil omega-3 and depression.

Whereas fish oil contains long-chain omega-3 EPA and DHA fatty acids, plant-based edible oils like soybean contain short-chain omega-3 ALA which must be metabolized after consumption to EPA and DHA in the body, hence the choice of soybean oil for the control group.

Most clinical trials on long-chain omega-3 EPA and DHA fatty acids have also used plant-based oils such as olive oil, soybean, canola, palm oil, corn oil or sunflower for the control group in fish oil omega-3 interventions.