Food Cravings in Dementia

Why do some people with dementia put on a lot of weight? New research shows it may be an attack on the brain area regulating eating habits. Learn what happens, as well as what to do about it.

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Dementia can cause dramatic changes in eating habits. Sometimes habits change into a pattern of eating more of certain foods, sometimes less. As the saying goes, "If you have seen one person with dementia, you have seen one person with dementia."

In a focused University of Waterloo study, researchers focused on what happens in a brain to trigger the over-eating of high-calorie snacks. They discovered that overindulging in high-calorie snacks is partly caused by lapses in a very specific part of the brain.

The study, published in Psychosomatic Medicine: Journal of Biobehavioral Medicine, is the first to conclusively link reduced operation of the dorsolateral prefrontal cortex with self-restraint in the dietary context.

“It has long been thought that the dorsolateral prefrontal cortex helps to keep automatic, or knee-jerk, reactions in check,” said Professor Peter Hall, senior author on the study. “We discovered that when you temporarily dampen the operation of this particular part of the brain, strongly engrained—and quite universal—preferences for high calorie foods start to hijack people’s thought patterns and even their eating patterns.”

The prefrontal cortex is known to be implicated in the brain’s executive functions, which typically allow people to engage in voluntary control over their behavior.   While prior studies have shown that boosting activity in the prefrontal cortex reduces cravings for unhealthy foods, this is the first study to show that reducing activity leads to more cravings and food consumption.

The study used continuous theta burst stimulation, a form of transcranial magnetic stimulation, to temporarily reduce activity in participants’ left dorsolateral cortex. After receiving theta burst stimulation, participants not only reported greater food cravings for calorie-dense food, but ate more junk food during a taste test than when they received a bogus stimulation.

“This is the first study to demonstrate that taking the prefrontal cortex temporarily offline results in increased snacking,” said Cassandra Lowe, doctoral student in the School of Public Health and Health Systems and lead author on the paper.

There are proven methods of enhancing the strength of the prefrontal cortex. These include:

1. Engaging in aerobic exercise
2. Avoiding alcohol
3. Getting enough sleep.

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University of Waterloo
In just half a century, the University of Waterloo, located at the heart of Canada's technology hub, has become one of Canada's leading comprehensive universities with 35,000 full- and part-time students in undergraduate and graduate programs. Waterloo, as home to the world's largest post-secondary co-operative education program, embraces its connections to the world and encourages enterprising partnerships in learning, research and discovery. In the next decade, the university is committed to building a better future for Canada and the world by championing innovation and collaboration to create solutions relevant to the needs of today and tomorrow. For more information about Waterloo, please visit www.uwaterloo.ca.