Associations between cod liver oil use and symptoms of depression: the Hordaland Health Study.
BACKGROUND
Clinical trials suggest that omega-3 fatty acids improve the outcome of depression. This study aimed to evaluate the association between intake of cod liver oil, rich in omega-3 fatty acids, and high levels of symptoms of depression and anxiety in the general population.


METHODS
We used data from the "The Hordaland Health Study '97-'99" (HUSK), a population based cross-sectional health survey from Norway including 21,835 subjects aged 40-49 and 70-74 years. Symptoms of depression and anxiety were measured by The Hospital Anxiety and Depression Scale (HADS). We used logistic regression to study associations.


RESULTS
Among the participants, 8.9% used cod liver oil daily. A total of 3.6% had high levels of depressive symptoms. The prevalence of such depressive symptoms among the subjects who used cod liver oil daily was 2.5%, as compared to 3.8% in the rest of the population. The users of cod liver oil were significantly less likely to have depressive symptoms than non-users after adjusting for multiple possible confounding factors (odds ratio=0.71, 95% confidence interval 0.52 to 0.97). These factors included age, gender, smoking habits, coffee consumption, alcohol consumption, physical activity, and education. In addition, we found that the prevalence of high levels of depressive symptoms decreased with increasing duration (0-12 months) of cod liver oil use (multivariate adjusted test for trend, P=0.04). We were only able to study this latter association in a subset of the population aged 40-46 years.


CONCLUSIONS
Data are cross sectional.


CONCLUSIONS
The findings indicate that regular use of cod liver oil is negatively associated with high levels of depressive symptoms in the general population.
Raeder
Maria Baroy
MB
Dr. Einar Martens' Research Group for Biological Psychiatry, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Helse Bergen HF, N-5021 Bergen, Norway. Maria.Rader@uib.no
Steen
Vidar M
VM
Vollset
Stein Emil
SE
Bjelland
Ingvar
I
D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D003060:Cod Liver Oil / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D015438:Health Behavior; D006306:Health Surveys; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009664:Norway; D013223:Statistics as Topic
D015525:Fatty Acids, Omega-3; D003060:Cod Liver Oil