Obesity and Night Eating Syndrome: Valuable Help from EPA and DHA

Night eating syndrome is an eating disorder characterized by uncontrolled food consumption during the night and associated with anorexic behaviors during the day. It is known that psychological disorders of this type increase the risk of gaining weight up to obesity, but the mechanisms that trigger this behavior are not yet certain. A new study revealed that omega-3s could slow down the weight gain associated with these and other eating disorders.

This hypothesis was developed by Garret FitzGerald and his collaborators at the University of Pennsylvania in Philadelphia (USA), who through a series of experiments on mice revealed the involvement of Omega-3s in communication between fat cells and the brain of those who eat at unusual hours. According to the report in Nature Medicine, it is enough to delete from fat a gene that controls the biological clock to cause the animals to eat at the wrong time, decrease Omega-3 levels in cells, and become obese. The good news, however, is another: simply administering EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the two Omega-3s abundant in fish, restores everything to normal.

Eating at Night: A Communication Problem

Every organism manages to maintain a balance between energy consumed and energy 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. Indeed, besides storing and releasing energy, fat cells communicate to the brain the amounts of stored fat. The messenger carrying these signals is leptin, a hormone that increases energy consumption and reduces food intake through mechanisms regulated by the brain area called the hypothalamus.

FitzGerald and colleagues discovered that deleting a gene responsible for the biological clock in fat cells causes mice, which normally eat at night, to start feeding during the day. This behavior, scientists explained, is associated with altered hypothalamic activity. Looking more closely at this mechanism, researchers observed decreased levels of EPA and DHA in the fat cells of these mice. Consequently, when the animals ate out of schedule, the secretion of these Omega-3s into the blood and their presence in the hypothalamus appeared reduced.

Solving the Problem with Omega-3s

Georgios Paschos, first author of the study, explained that the most exciting result was managing to eliminate abnormal fluctuations in Omega-3 levels and gene expression in the hypothalamus, the eating behavior, and obesity tendency simply by administering EPA and DHA to the mice. These results demonstrate the central role played by fat cells and the Omega-3s they secrete in guaranteeing communication with the hypothalamus, which can then appropriately regulate energy consumption. Furthermore, this study reveals that alterations in the mechanisms involving Omega-3s may underlie the higher incidence of obesity among night-shift workers or those suffering 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