Obesity and night eating syndrome: valuable help from EPA and DHA

Nocturnal eating syndrome is an eating disorder characterized by uncontrolled food consumption during the night and associated with anorexic behavior during the day. Such psychological disorders are known to increase the risk of gaining weight to the point of obesity, but the mechanisms that trigger this behavior are not yet certain. A new study has unveiled that omega-3s could curb the weight gain associated with these and other eating disorders. 

Developing this hypothesis are Garret FitzGerald and his collaborators at the University of Pennsylvania in Philadelphia (United States), who through a series of experiments in mice have unveiled the involvement of Omega-3s in the communication between fat cells and the brains of those who eat at unusual times. According to reports in the pages of Nature Medicine, simply deleting a gene that controls thebiological clock from the fat is enough to cause the animals to eat off schedule, Omega-3 levels in the cells to decrease, and the mice to become obese. The good news, however, is another: simply giving the animals EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the two Omega-3s in which fish are rich, is enough to bring everything back to normal.

Eating at night: a communication problem

Every body manages to maintain a balance between the energy consumed and that taken in with food thanks to complex signals exchanged between the nervous system and other organs, such as the liver and heart. Fat also participates in this message exchange. In fact, in addition to storing and releasing energy, fat cells communicate the amounts of fat crammed into them to the brain. Carrying these messages is leptin, a hormone that increases energy expenditure and reduces food intake through mechanisms regulated by the area of the brain called the hypothalamus. 

FitzGerald and colleagues found that deleting a gene responsible for the biological clock in fat cells causes mice, which typically eat at night, to start feeding during the day. This behavior, the scientists explained, is associated with alterations in the activity of the hypothalamus. Going into more detail about this mechanism, the researchers observed decreased levels of EPA and DHA in the fat cells of these mice. As a result, when the animals ate after hours the secretion of these omega-3s into the blood and their presence in the hypothalamus appeared reduced.

Solve the problem with omega-3s

Georgios Paschos, first author of the research, explained that the most exciting result was being able to eliminate abnormal fluctuations in Omega-3 levels and gene expression in the hypothalamus, eating behavior and obesity tendency simply by administering EPA and DHA to mice. These results demonstrate the central role played by fat cells and the Omega-3s they secrete in ensuring communication with the hypothalamus, which, in this way, can appropriately regulate energy consumption. On the other hand, this study also reveals that alterations in the mechanisms in which Omega-3s participate could underlie the higher incidence of obesity among those who work at night or in those who suffer from sleep disorders. 

Source Paschos GK, Ibrahim S, Song WL, Kunieda T, Grant G, Reyes TM, Bradfield CA, Vaughan CH, Eiden M, Masoodi M, Griffin JL, Wang F, Lawson JA, Fitzgerald GA, "Obesity in mice with adipocyte-specific deletion of clock component Arntl," Nat Med. 2012 Nov 11. doi: 10.1038/nm.2979