In a new study, Ohio State researchers discovered consumption of fish oil reduced inflammation and anxiety among a group of healthy young people.
Researchers believe the findings suggest the elderly and people at high risk for certain diseases may benefit from similar dietary supplements.
The research is published in the journal Brain, Behavior and Immunity and is the latest from more than three decades of research into links between psychological stress and immune response.
The benefits from omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been debated for the last 30 years.
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.
According to researchers, psychological stress has repeatedly been shown to increase cytokine production. Thus, researchers initiated the study to discover if increasing omega-3 might mitigate that process, reducing inflammation.
To test their theory, they turned to a familiar group of research subjects – medical students. Some of the earliest work these scientists did showed that stress from important medical school tests lowered students’ immune status.
“We hypothesized that giving some students omega-3 supplements would decrease their production of proinflammatory cytokines, compared to other students who only received a placebo,” explained Janice Kiecolt-Glaser, Ph.D., professor of psychology and psychiatry.
“We thought the omega-3 would reduce the stress-induced increase in cytokines that normally arose from nervousness over the tests.”
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.
“The supplement was probably about four or five times the amount of fish oil you’d get from a daily serving of salmon, for example,” said Martha Belury, Ph.D., professor of human nutrition and co-author in the study.
However, the study did not go completely as planned, as changes in the medical school curriculum provided benefit to the students.
“These students were not anxious. They weren’t really stressed. They were actually sleeping well throughout this period, so we didn’t get the stress effect we had expected,” Kiecolt-Glaser said.
But the psychological surveys clearly showed an important change in anxiety among the students: Those receiving the omega-3 showed a 20 percent reduction in anxiety compared to the placebo group.
An analysis of the of the blood samples from the medical students showed similar important results.
“We took 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 Dr. Ron Glaser, professor of molecular virology.
“We saw a 14 percent 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.
While the study showed the positive impact omega-3 supplements can play in reducing both anxiety and inflammation, the researchers aren’t willing to recommend that the public start adding them to the daily diet.
“It may be too early to recommend a broad use of omega-3 supplements throughout the public, especially considering the cost and the limited supplies of fish needed to supply the oil,” Belury said. “People should just consider increasing their omega-3 through their diet.”
Source: Ohio State University