Food Ingredients May Be as Effective as Antidepressants
Researchers discover 'mood foods' relieve signs of depression
FOR IMMEDIATE RELEASE:
February 10, 2005
Belmont, MA - Eating the right foods could have the same effect as taking traditional antidepressant medications, report researchers at Harvard-affiliated McLean Hospital.
In a paper published in the Feb. 15 issue of Biological Psychiatry (Abstract), a team of researchers report that omega-3 fatty acids and uridine, two naturally occurring substances in many foods, including fish, walnuts, molasses and sugar beets, prevented the development of signs of depression in rats as effectively as antidepressant drugs.
"Giving rats a combination of uridine and omega-3 fatty acids produced immediate effects that were indistinguishable from those caused by giving the rats standard antidepressant medications," explains lead author of the study William Carlezon, PhD, director of McLean's Behavioral Genetics Laboratory.
The results are encouraging, but shouldn't be too surprising, says co-author of the study Bruce Cohen, MD, PhD, president and psychiatrist in chief for McLean Hospital. "Cultures eating diets rich in fish with high amounts of omega-3 fatty acids tend to show a lower prevalence of major depression. Many elements of diet can affect the brain and could enhance or detract from this benefit."
In the study, researchers examined how omega-3 fatty acids and uridine affected the behavior of rats exposed to stress. Normally, rats quickly develop learned helplessness behavior - believed to reflect despair in animal models - when tested repeatedly under stressful conditions. Rats given injections of uridine or fed a diet enriched with high amounts of omega-3 fatty acids showed fewer signs of despair than untreated rats.
When given separately and then in combination, the researchers found a striking difference in the speed at which uridine and omega-3 fatty acids had their effects. While the effects of uridine were immediate, the effects of omega-3 fatty acids took a month to develop, and shorter treatments of omega-3 fatty acids alone (three to 10 days) were ineffective in relieving the signs of depression in the rats. When the rats were given the combined treatment of normally ineffective amounts of uridine and short omega-3 fatty acid treatment periods, however, beneficial effects emerged much quicker.
Although the reasons for the effectiveness of these treatments are not understood, important clues are beginning to emerge. A likely possibility, says Carlezon, is that these substances target the brain's mitochondria, a microscopic energy-producing component found in all cells of the body. Mitochondria produce energy through reactions that occur on their membranes.
"Omega-3 fatty acids may make the mitochondrial membranes more flexible and uridine may provide raw material to make chemical reactions occur more readily," adds co-author Perry Renshaw, MD, PhD, director of McLean's Brain Imaging Center. "These conditions would be more conducive to the production of energy, and boost communication among neurons in key areas of the brain."
Evidence that the brain's mitochondria may be involved in mood and certain psychiatric conditions is accumulating rapidly. Other McLean Hospital researchers reported recently that there are dramatic alterations in mitochondrial genes within the brains of people affected with bipolar disorder, a condition that involves cycles of depression. "This work provides more evidence that our behavior - including the selection of the foods we use to fuel our body - can have a tremendous influence on how we feel and act," says Carlezon. "The possibility that sustained improvements in diet may have beneficial effects on mood is definitely worth closer consideration."
McLean Hospital maintains the largest research program of any private, U.S. psychiatric hospital. It is the largest psychiatric facility of Harvard Medical School, an affiliate of Massachusetts General Hospital and a member of Partners HealthCare. For more information about this study or other research being conducted at McLean Hospital, go to www.mclean.harvard.edu.