Even before obesity occurs, eating fatty and sugary foods causes chemical changes in the brain, meaning that going on a diet might feel similar to going through drug withdrawal, according to a study published today by Dr. Stephanie Fulton of the University of Montreal's Faculty of Medicine and its affiliated CRCHUM Hospital Research Centre.
"By working with mice, whose brains are in many ways comparable to our own, we discovered that the neurochemistry of the animals who had been fed a high fat, sugary diet were different from those who had been fed a healthy diet," Fulton explained. "The chemicals changed by the diet are associated with depression. A change of diet then causes withdrawal symptoms and a greater sensitivity to stressful situations, launching a vicious cycle of poor eating."
The research team feed one group of mice a low-fat diet and a high fat diet to a second group over six weeks, monitoring how the different food affected the way the animals behave. Fat represented 11% of the calories in the low-fat diet and 58% in the high-fat diet, causing the waist size in the latter group to increase by 11% – not yet obese. Next, Fulton and her colleagues use a variety of scientifically validated techniques to evaluate the relationship between rewarding mice with food and their resulting behaviour and emotions. They also actually looked at the brains of the mice to see how they had changed.
Mice that had been fed the higher-fat diet exhibited signs of being anxious, such as an avoidance of open areas. Moreover, their brains have been physically altered by their experiences. One of molecules in the brain that the researchers looked at is dopamine. It enables the brain to rewards us with good feelings, thereby encouraging us to learn certain kinds of behaviour. This chemical is the same in humans as it is in mice and other animals. In turn, CREB is a molecule that controls the activation of genes involved in the functioning of our brains, including those that cause the production of dopamine. It contributes to memory formation. "CREB is much more activated in the brains of higher-fat diet mice and these mice also have higher levels of corticosterone, a hormone that is associated with stress. This explains both the depression and the negative behaviour cycle," Fulton said. "It's interesting that these changes occur before obesity. These findings challenge our understanding of the relationship between diet, the body and the mind. It is food for thought about how we might support people psychologically as they strive to adopt healthy eating habits, regardless of their current corpulence."
About the study
The International Journal of Obesity issued the study via advanced online publication on December 11, 2012. The research was funded by the Natural Sciences and Engineering Research Council of Canada, the Canadian Diabetes Association and the Canada Foundation for Innovation. Fulton and her team are part of a research network that is working together to address the biological reasons for obesity and its related diseases, such as cardiovascular diseases, type 2 diabetes, some cancers, and of course depression. She is based at the Montreal Diabetes Centre, an institution associated with the CRCHUM and four Montreal universities that brings together facilities for clinical research, cell biology and microscopy research, and rodent physiology research
William Raillant-Clark | EurekAlert!
Why might reading make myopic?
18.07.2018 | Universitätsklinikum Tübingen
Unique brain 'fingerprint' can predict drug effectiveness
11.07.2018 | McGill University
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences