You may be familiar with the saying, "You are what you eat," but did you know the food you eat could impact your memory?
Auriel Willette, assistant professor, and his team of researchers in
Iowa State University's Department of Food Science and Human Nutrition
discovered a satiety hormone that, at higher levels, could decrease a
person's likelihood of developing Alzheimer's disease. A paper outlining
the results of their study recently was accepted for publication in Neurobiology of Aging.
Using data from the Alzheimer's Disease Neuroimaging Initiative
(ADNI), the researchers looked at the satiety hormone, Cholecystokinin
(CCK), in 287 people. CCK is found in both the small intestines and the
brain. In the small intestines, CCK allows for the absorption of fats
and proteins. In the brain, CCK is located in the hippocampus, which is
the memory-forming region of the brain, Willette said.
The researchers found for individuals who have higher CCK levels,
their chance of having mild cognitive impairment, a precursor state to
Alzheimer's disease, or Alzheimer's disease decreased by 65 percent.
"It will hopefully help to shed further light on how satiety
hormones in the blood and brain affect brain function," Willette said.
Alexandra Plagman, lead author and graduate student in nutritional
science, said they chose to focus on CCK because it is highly expressed
in memory formation. The researchers wanted to see if there was any
significance between levels of CCK and levels of memory and gray matter
in the hippocampus and other important areas.
They also looked p-tau and tau proteins, which are thought to be
toxic to the brain, to see how these might impact CCK and memory. They
found that as tau levels increased, higher CCK was no longer related to
less memory decline.
The researchers hope this study will encourage others to look into
the nutritional aspect of diets, versus just looking at caloric intake.
Plagman already is looking at how diet impacts an individual's CCK
levels through researching fasting glucose and ketone bodies.
"By looking at the nutritional aspect, we can tell if a certain diet
could prevent Alzheimer's disease or prevent progression of the
disease," Plagman said.
"The regulation of when and how much we eat can have some
association with how good our memory is," Willette added. "Bottom line:
what we eat and what our body does with it affects our brain."