Low EPA Levels Seen in the Elderly with Major Depression
Although there are many reasons why people develop major depression, the condition is more frequent in younger than older adults. Nonetheless, it is a concern in the aging population. In the elderly, depression is more likely to occur in those with impaired cognition and in certain disturbances of endocrine metabolism. Depression also occurs more frequently in people with low fish consumption or low levels of long-chain omega-3 fatty acids in their blood. Higher levels of these fatty acids have also been linked to slower loss of cognition in aging. If this link between depression and nutrition becomes firmly established, it offers a fairly simple way to lower the chance of developing this unwelcome condition.
To learn more about the link between long-chain omega-3s and major depression in aging, investigators in France examined the omega-3 fatty acid levels in elderly individuals recruited from the general population. To be eligible for the study, participants had to be at least 65 years old and living in the community. Those who were considered to have major depression had scores on a depression assessment rating above an established level for the disorder. Those free of depression served as controls. On average, the participants were 75 years of age.
The investigators then measured the concentrations of omega-3 fatty acids in the blood of both groups. They observed that the concentrations of EPA (eicosapentaenoic acid), one of two major long-chain omega-3 fatty acids, were significantly lower in the depressed older adults compared with those free of depression. The concentrations of DHA (docosahexaenoic acid) did not differ in the two groups. Other studies, however, have reported reduced DHA levels in depression, including the DHA content of specific regions in the brain cortex.
In addition, patients taking antidepressant medications had more severe symptoms as their EPA dropped. This relationship with severity of the condition held after accounting for other variables, such as high blood cholesterol levels and the number of drugs the patients were taking.
Because this was an observational study, it does not address the question of causation. We do not know whether the low levels of EPA were the result of depression or increased susceptibility to it. To date, other evidence favors the latter interpretation. There is evidence suggesting that inflammation is linked to depression. EPA is an important substance for reducing inflammation, suggesting that a connection between low EPA and major depression is plausible.
Considering the many other health benefits associated with regular fish or long-chain omega-3 consumption on heart health, visual function and cognition, it would reflect the wisdom of aging to have fish on the menu at least twice a week.
SOURCE: Fats of Life Newsletter