Washington: Eating sweet foods causes the brain to form a memory of the meal, which may help us control our eating habits, a new study has found. “We make decisions like ‘I probably won’t eat now. I had a big breakfast.’ We make decisions based on our memory of what and when we ate,” said Marise Parent, professor in the Neuroscience Institute at Georgia State University in US.
Forming memories of meals is important to a healthy diet. A previous study shows that disrupting the encoding of the memory of a meal in humans, such as by watching television, increases the amount of food they consume during the next meal, researchers said.
The researchers showed that neurons in the dorsal hippocampus, the part of the brain that is critical for episodic memory, are activated by consuming sweets. Episodic memory is the memory of autobiographical events experienced at a particular time and place.
In the study, a meal consisting of a sweetened solution, either sucrose or saccharin, significantly increased the expression of the synaptic plasticity marker called activity-regulated cytoskeleton-associated protein (Arc) in dorsal hippocampal neurons in rats. Synaptic plasticity is a process that is necessary for making memories.
“We think that episodic memory can be used to control eating behaviour,” Parent said. That possibility is supported by the researchers’ previous work, which showed that temporarily inactivating dorsal hippocampal neurons following a sucrose meal – the period during which the memory of a meal forms – accelerates the onset of the next meal and causes rats to eat more.
Researchers have found that people with amnesia will eat again if presented with food, even if they have already eaten, because they have no memory of the meal. To understand energy regulation and the causes of obesity, scientists must consider how the brain controls meal onset and frequency, Parent said.
Studies have found that increased snacking is correlated positively with obesity, and obese individuals snack more frequently than people who are not obese, researchers said. The study was published in the journal Hippocampus.