Medical

Canola oil linked to Alzheimer's complications in new study

Canola oil linked to Alzheimer...
While canola oil, from the rapeseed plant shown here, can be healthy for our hearts, it might not be so good for Alzheimer's disease
While canola oil, from the rapeseed plant shown here, can be healthy for our hearts, it might not be so good for Alzheimer's disease
View 1 Image
While canola oil, from the rapeseed plant shown here, can be healthy for our hearts, it might not be so good for Alzheimer's disease
1/1
While canola oil, from the rapeseed plant shown here, can be healthy for our hearts, it might not be so good for Alzheimer's disease

Canola is generally considered a healthy oil thanks to its ability to reduce LDL cholesterol in the blood and lower the risk of heart disease. A new animal study out of Temple University, though, has shown that the vegetable-based fat increases substances in the brain that can lead to Alzheimer's disease.

"Canola oil is appealing because it is less expensive than other vegetable oils, and it is advertised as being healthy," explained study senior author Domenico Praticò, director of the Alzheimer's Center at Temple's Lewis Katz School of Medicine. "Very few studies, however, have examined that claim, especially in terms of the brain."

So the researchers set out to work with mice that had been engineered to contract Alzheimer's disease in the same way the condition affects humans: asymptomatic in early life and full-blown cognitive impairment when the rodents aged. At six months of age, when the mice still had no symptoms, they were split into two groups. One group was given a normal diet while the other had a normal diet plus the addition of approximately two tablespoons of canola oil each day.

Six months later, maze tests revealed the mice on the canola diet showed a decline in their working memory capacities compared to the other group. The canola-oil group also had gained a fair bit more weight than their non-oil-eating studymates.

The decline in cognitive function in the group of mice fed the oil-rich diet also corresponded to chemical changes in the brain. The canola-oil group showed a decrease in the levels of a protein known as amyloid beta 1-40. Amyloids are well-known in Alzheimer's research as the substances that form sticky clumps in the brain. But amyloid beta 1-40 actually helps prevent those clumps from forming by buffering amyloid beta 1-42, an insoluble form of the protein, so a reduction isn't a good thing.

As a result, in the brains of the mice that were on the oil-rich diets, an increase in amyloid plaques was noted with the substances wrapping around neurons, decreasing the number of contacts between them and pointing to serious synapse injuries. As synapses – the space between neurons where chemical signals are transmitted – are key to memory functions,the findings fit with the decreased ability the mice demonstrated in running the maze.

"Even though canola oil is a vegetable oil, we need to be careful before we say that it is healthy," 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."

One such oil is olive oil, which Praticò and his team showed could actually reduce amyloid plaques in mouse models in a study earlier this year.

The next step for the researchers is to conduct studies over a shorter period of time to see just how quickly Alzheimer's-disease-affected brains begin showing the damage. Even though the study showed no impact from canola oil on other disease-related markers such as inflammation or tau – another protein linked to Alzheimer's – the researchers say they will also delve into the role the fat might play in other conditions.

"We also want to know whether the negative effects of canola oil are specific for Alzheimer's disease," Dr. Praticò concluded. "There is a chance that the consumption of canola oil could also affect the onset and course of other neurodegenerative diseases or other forms of dementia."

The research has been published in the journal Nature.

Source: Temple University via EurekAlert

14 comments
Fairly Reasoner
What's the equivalent amount for an average human when compared to 2 tablespoons a day for a rat?
Grunchy
A regular mouse weighs anywhere from 30g to 90g. A teaspoon of canola oil is about 4g so two teaspoons is 8g. So assuming at the higher end of the scale, that's like eating about 10% of your body weight in canola oil each day (I weigh 190 lbs so that would be 19 lbs of canola oil per day). That seems extraordinarily high except mice eat about 15g of food per 100g of body weight per day, so if you had an 80g mouse it would eat about 12g of food. So if 8g is canola oil then it presumably eats 4g of other food. Another interesting thing is that canola is about 8.8 calories per g, so 8g has about 70 calories. No wonder the mouse is getting fat? (If I ate 15% of my body weight per day that would amount to 28.5 lbs of food per day - I don't do this).
Tommygun1969
Firstly, the study was with mice, not even routes. According to this site, a mouse needs around 160kCal per day. And adult human would generally need 10 times that. Just using that value of 10x, 2 tblspoons for a mouse would be like 20 for a human. That's about 600mls of oil or an entire pint! At 8 calories/ml that would also be 4800kCal. Um, yeah, I think that would cause all sorts of problems, weight gain obviously (as per the study). I'm not sure one could single out the fact the oil was Canolo oil as being the problem them! I'd take this study with a grain of canola oil.
Fritz
I fully agree with Grunchy. Despite we use canola oil as lubricant for chain saw and biodiesel only.
MerlinGuy
Mice that are engineered to get Alzheimers. Massive amounts of fats. A academic environment where researchers must publish exciting data. What could possibly be wrong there? Universities are now our new religion.
BrianK56
Per body mass of a mouse, one drop per day is an overload compared to human consumption.
c4jjm
Another fine example of 'scientific' study gone horribly wrong. As others have mentioned...wait a minute, you made them fat, and that is the fault specifically of Canola Oil??? Hold ON! Now, if they also tried other oils, and these ALSO made the mice fat, but did not cause AD, then sure, its still a valid experiment. Now reading further, YES, they tested mice with EVOO, so I went and read that paper....wherein they CONTROLLED the diet to prevent the mice from gaining weight in the EVOO rich group (I'm sure they did not get anywhere near 2 tsp.)...which means they cannot compare the two studies... What a load of ____. If they really want to say canola oil is worse than other oils, they need to do the experiment EXACTLY the same for multiple types of oil, otherwise all that can be said is that eating ~1lb of pure oil a day will lead you to AD!
Nik
Two table spoons to a mouse is like half a bath full to a human, its a wonder they didnt just drown in it.
Chuck Leinweber
I'd like to see a study where one group gets Canola oil and the control group gets some other oil - say Olive oil. What this study established, to me, is that eating a bunch of oil, of any kind, would exacerbate Alzheimer's. Yet Canola gets a bad rap.
Douglas Bennett Rogers
Canola oil is one of the main culprits in processed food, moving the omega 6/ omega 3 ratio toward omega 6.