No mental health benefit from fish oil

In spite of conventional wisdom that the omega-3 fatty acids found in fish can protect against depression, a large new study from Harvard School of Public Health (HSPH) found no such benefit.

Researchers examined the link between suicide and fatty acid intake among more than 205,000 participants in three long-term studies. Looking at data from biennial questionnaires administered to 42,290 men enrolled in the Health Professionals Follow-up Study (1988-2008), 72, 231 women in the Nurses’ Health Study (1986-2008), and 90,836 women in the Nurses’ Health Study II (1993-2007), they found no evidence that intake of fatty acids or fish lowered the risk of suicide.

“From a public health perspective, this is highly significant,” said Alexander Tsai, assistant professor of psychiatry at Harvard Medical School and the Massachusetts General Hospital and a research fellow at the Harvard Center for Population and Development Studies, who co-led the study with Michel Lucas, visiting scientist in the HSPH Department of Nutrition. “The vast majority of previous literature on whether there is a mental health benefit from fatty acid intake has been based on depression screening data. Our study represents one of the few times—and it is certainly the largest of its kind—that this relationship has been studied with hard data on suicide mortality.”