The prevalence of major depression has increased and the age of onset has decreased in every decade during the 2000 century in the western world. Psychiatrists in the United States are looking into the effect low concentrations of omega-3 fatty acids could have on depressive patients.
The intake of dietary lipids has changed over the years mainly by increasing the content of omega-6 oils from seeds and vegetables in exchange for saturated fat and a reduction in the intake of omega-3 fatty acids. The authors of a new study aim to demonstrate that depressive patients have low concentrations of omega-3 fatty acids probably due to low intake of fish in the diet.
Polyunsaturated fatty acids are important components of the human brain acting not only as structural components of nerve cells but also taking place in the transmission of signals along the neurones.
The growing foetus incorporate large amounts of long chain omega-6 and omega-3 fatty acids during the last months of pregnancy and it is important for the pregnant woman to secure sufficient intake of these fatty acids in the diet. The study suggests that a woman deprived of omega-3 fatty acids during the end of pregnancy and the time after delivery could lead to depressive disease.
Depression in the early phase after delivery afflicts 10-15 per cent of all mothers, the authors add. Those who had depression after pregnancy run a 50 per cent risk of having the same condition during new pregnancies. In a recently published article US scientists found low contents of omega-3 fatty acids, especially DHA, in mothers milk and red blood cells of women with post- partum depression: depressive disease after delivery (2). The difference was significantly different from those without depression. The reason for this finding was related to low intake of fatty fish like salmon and herring containing large amounts of DHA.
A psychiatrist in Boston, USA, tried high doses of omega-3 fatty acids on his manic-depressive patients and found that those treated remained without symptoms to a larger extent than those who did not get omega-3 fatty acids (3).
One of the psychiatrists participating in the study, Dr. Marlene Freeman, took interest in the possibility of treating pregnant women suffering from depression with omega-3 fatty acids. Dr. Freeman, now active in Tucson, Arizona, started the Women's Mental Health Program enrolling 50 pregnant women with previous postpartum depression.
They will be randomly allocated to treatment with 3 capsules of Triomar from Pronova Biocare containing 60 per cent of omega-3 fatty acids per capsule or placebo for two months. The study, sponsored by the US National Institute of Health, will be completed next summer.
References: 1) Maes M, Christophe A, Delanghe J et al. Lowered omega-3 polyunsaturated fatty acids in serum phospholipids and cholestryl esters of depressed patientsPsychiatry Res 1999;22:275-291
2) Hibbeln JR. Seafood consumption, the DHA content of mother's milk and prevalence rates of postpartum depression: a cross-national, ecological analysis.J Affective Disorders 2001
3) Stoll AL, Severus E, Freeman MP et al. Omega-3 fatty acids in bipolar disorderArch Gen Psychiatry 1999;56:407-412