Other researchers made presentations on the topic as well. To better understand the brain functions of individuals with anorexia nervosa and bulimia nervosa, Walter H. Kaye, MD, and colleagues at the University of California, San Diego, used fMRI to examine the brain’s response to the taste of sucrose and an artificial sweetener and the brain’s response to pictures of palatable foods, compared with color-matched neutral objects. Their findings suggest that individuals who undereat or overeat have an altered sensitivity when consuming sucrose.
Julie L. Fudge, MD, of the University of Rochester Medical Center, followed the “taste pathway” in humans to better understand how information received by various areas of the brain is involved in eating behaviors. Her findings suggest a way that emotional associations with food can converge with taste and instinctive sensations to influence eating behavior.
Disturbances in appetite and weight regulation affect a significant proportion of the US population, and obesity is considered a national epidemic. One in every three adults and one of six children are obese, a condition that arises from chronic imbalances between energy intake and expenditure.
“The studies in this panel represent a growing body of research linking the brain and the wiring in the brain to overeating and obesity,” Dr. Volkow commented. “We really need to do much more work to better understand integration with processes that regulate food intake and reward processing in the brain. This research opens the doors to a much greater understanding of obesity.”
Omega-3 Supplements Show Promise in Alleviating Depression
A new analysis of the effects of omega-3 essential fatty acids offers the hope of enhanced treatment options for patients with depression. Two critical omega-3 essential fatty acids available from certain food or nutritional supplements but not manufactured by the body—eicosapentaenoic acid (EPA) and docosahexaenoic (DHA)—may play a role in optimal brain functioning and have antidepressant benefits that have not been fully recognized.
In a meta-analysis of 15 randomized, double-blind, placebo-controlled studies, researchers from the University of Illinois at Chicago, led by John M. Davis, MD, found that patients taking omega-3 with either EPA or a combination of EPA and DHA experienced clear antidepressant benefits. However, across studies, patients taking the pure DHA form of omega-3 showed no antidepressant effect.
“Our analysis clarifies the precise type of omega-3 fatty acid that is effective for people with depression and explains why previous findings have been contradictory,” said Dr. Davis. “The EPA predominant formulation is necessary for the therapeutic action to occur. The DHA predominant formulation does not have antidepressant efficacy.”
Although the investigators noted that omega-3 produces beneficial effects in patients with depression, EPA does not improve mood in persons who are not depressed. In several studies, people without depression experienced no difference in mood as a result of omega-3 consumption.
In another study, Dr. Davis and his team found that women with inadequate omega-3 intake were more likely to experience depression during and after pregnancy than were women with adequate omega-3 in their diets.
“The findings are unambiguous,” said Dr. Davis. “Omega-3 fatty acids have antidepressant properties, and this effect is ready to be tested in a large study to establish the dose range and to pave the way for FDA approval. In the meantime, omega-3 fatty acids containing EPA could be useful to augment effects of antidepressant medications.”
However, the researchers cautioned that patients should always talk with their physician before taking omega-3 fatty acids to alleviate symptoms of depression.
Dr. Davis and colleagues are now examining the link between soy intake and depression, and they expect those findings to be published next year. He noted that soy products contain omega-6 fatty acids, which compete with omega-3 fatty acids.