If you’re on the dementia prevention track, you’ve probably read that olive oil and healthy fats containing omega-3s are linked to a lower risk of Alzheimer’s. We also know that a diet high in sugar can lead to a higher risk of dementia. And now scientists have added another item to the “don’t” list: canola oil.
Researchers at the Lewis Katz School of Medicine at Temple University found that consumption of canola oil caused worsened memory, worsened learning ability and caused weight gain in mice that are engineered to have Alzheimer’s.
The researchers who led the study are the same ones who found that a diet of extra-virgin olive oil reduced levels of amyloid plaques and tau and improved memory in the Alzheimer’s mice in a study earlier this year. They wanted to see if canola oil might have the same beneficial effect. “Canola oil is appealing because it is less expensive than other vegetable oils, and it is advertised as being healthy,” said Domenico Praticò, M.D., a lead author of the study. “Very few studies, however, have examined that claim, especially in terms of the brain.”
The mice were separated into two groups at six months before they showed signs of Alzheimer’s. One group was fed a normal diet; the other got a diet with the mouse equivalent of two tablespoons of canola oil daily. Six months later, the canola oil group weighed significantly more than the other group. They also did more poorly on memory tests. When scientists examined their brains, they found the canola oil mice had less amyloid beta 1-40, a more soluble type of the protein that is thought to have a protective role in the brain, acting as a buffer between the brain and the more harmful insoluble form, amyloid beta 1-42.
“Amyloid beta 1-40 neutralizes the actions of amyloid 1-42, which means that a decrease in 1-40, like the one observed in our study, leaves 1-42 unchecked,” said Praticò.
As a result, plaques were more plentiful in the canola oil mice and neurons were also more damaged.
“Even though canola oil is a vegetable oil, we need to be careful before we say that it is healthy,” said Praticò said. “Based on the evidence from this study, canola oil should not be thought of as being equivalent to oils with proven health benefits.”
Next, scientists plan to see whether canola oil might have an effect on other neurodegenerative diseases.
This study was published in the journal Scientific Reports.