The use of fish oils to mediate anxiety in a selected group of intelligent and healthy young people has suggested a positive correlation. The implications are that other groups, especially the elderly and individuals with complex disorders may also benefit. For over thirty years the relationships between stress and immune function have been explored and this is one of the latest papers published in the leading cross discipline journal Brain Behaviour and immunity.
Omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have long been considered as positive additives to the diet. Earlier research suggested that the compounds might play a role in reducing the level of cytokines in the body, compounds that promote inflammation, and perhaps even reduce depression.
Psychological stress has repeatedly been shown to increase cytokine production so the researchers wondered if increasing omega-3 might mitigate that process, reducing inflammation.
Medical students were selected to see if combining fish oils and exams would produce a reduction in stress promoted pro inflammatory cytokines – proteins released by and for the immune system linked to anxiety and depressive behaviour.
What did they do?
The team assembled a field of 68 first- and second-year medical students who volunteered for the clinical trial. The students were randomly divided into six groups, all of which were interviewed six times during the study. At each visit, blood samples were drawn from the students who also completed a battery of psychological surveys intended to gauge their levels of stress, anxiety or depression. The students also completed questionnaires about their diets during the previous weeks.
Half the students received omega-3 supplements while the other half were given placebo pills.
Part of the study, however, didn’t go according to plans.
Changes in the medical curriculum and the distribution of major tests throughout the year, rather than during a tense three-day period as was done in the past, removed much of the stress that medical students had shown in past studies.
But the psychological surveys clearly showed an important change in anxiety among the students: Those receiving the omega-3 showed a 20% reduction in anxiety compared to the placebo group.
An analysis of the of the blood samples from the medical students showed similar important results.
“Measurements of the cytokines in the blood serum, as well as measured the productivity of cells that produced two important cytokines, interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFa),” said Ron Glaser, professor of molecular virology, immunology & medical genetics and director of the Institute for Behavioral Medicine Research.
“We saw a 14% reduction in the amounts of IL-6 among the students receiving the omega-3.” Since the cytokines foster inflammation, “anything we can do to reduce cytokines is a big plus in dealing with the overall health of people at risk for many diseases,” he said.
While inflammation is a natural immune response that helps the body heal, it also can play a harmful role in a host of diseases ranging from arthritis to heart disease to cancer.
As with many studies before this the relationship between the availability of EFA’s and health promotion and tolerance is increasingly robust, and probably reflects the historical link between the availability of omega rich foods early in our evolution and the management of more drastic levels of stress and anxiety experienced by or forefathers.
 Janice K. Kiecolt-Glaser, Martha A. Belury, Rebecca Andridge, William B. Malarkey, Ronald Glaser Omega-3 supplementation lowers inflammation and anxiety in medical students: A randomized controlled trial
Brain, Behavior, and Immunity, In Press, Uncorrected Proof, Available online 19 July 2011