Canola Oil Might Impair Memory

Scientists in Pennsylvania say the untested claims of canola oil's healthfulness aren't based on facts and that it's better to stick with olive oil.

By Mary West
Dec. 8, 2017 10:40 UTC

Canola oil has long been pitched as a healthy cook­ing oil, but accord­ing to a new study that might not be entirely true.

Researchers found that what its man­u­fac­tur­ers call the world’s health­i­est oil” is actu­ally linked to obe­sity, mem­ory impair­ments and other harm­ful effects on the brain.

Our data would not jus­tify the increas­ing ten­dency of replac­ing olive oil with canola oil as part of a good and healthy dietary alter­na­tive in non-Mediterranean coun­tries.- Temple University

In recent years, the use of canola oil has become pop­u­lar due to its low cost and the per­cep­tion that it shares some of the health ben­e­fits of olive oil. However, the chronic con­sump­tion of canola oil hadn’t been stud­ied to see how it might affect the devel­op­ment of neu­ro­log­i­cal dis­eases.

In a recent study, senior author Domenico Praticò of the Lewis Katz School of Medicine at Temple University in Philadelphia and col­leagues under­took an inves­ti­ga­tion to see if it canola mea­sured up to its healthy billing.

The sci­en­tists divided mice mod­els with Alzheimer’s into two groups. One group was fed a diet that was aug­mented daily with the human equiv­a­lent of two table­spoons of canola oil, while the other was fed a nor­mal diet.

All the mice were observed for six months. When the mice on the canola-rich diet reached one year in age, they had gained weight and were suf­fer­ing from a sig­nif­i­cantly impaired mem­ory, com­pared to the mice in the con­trol group.

In addi­tion, neuro bio­chem­i­cal analy­ses showed they had a reduc­tion in synap­tic integrity (a synapse refers to the junc­tion between nerve cells where impulses pass). The decrease in synap­tic integrity means the trans­mis­sion of impulses from one nerve cell to another doesn’t func­tion as well. Earlier stud­ies have shown this loss is strongly cor­re­lated to the cog­ni­tive decline in AD.

The mice that were fed canola oil didn’t show an increase in the amy­loid plaque or tau neu­rofib­ril­lary tan­gles char­ac­ter­is­tic of AD. Nonetheless, they had a sta­tis­ti­cally sig­nif­i­cant ele­va­tion in a para­me­ter called Aβ 42/40, which sug­gests they had a higher like­li­hood of accu­mu­lat­ing plaque in the brain.

Overall our find­ings do not pro­vide sup­port to some of the cur­rent ideas sug­gest­ing healthy ben­e­fits deriv­ing from the reg­u­lar con­sump­tion of canola oil,” the authors wrote. Although we rec­og­nize that more stud­ies are needed to inves­ti­gate the bio­log­i­cal effects of this oil, our data would not jus­tify the increas­ing ten­dency of replac­ing olive oil with canola oil as part of a good and healthy dietary alter­na­tive in non-Mediterranean coun­tries.”

In an inter­view with Olive Oil Times, Simon Poole, physi­cian and author of The Olive Oil Diet con­trasted the health ben­e­fits of the MedDiet with the appar­ent health risks of canola oil.

While we need to be cau­tious about extrap­o­lat­ing from ani­mal stud­ies, this study con­firms that we can’t replace olive oil with other oils and expect to see the same health ben­e­fits. Previous work by the same research team demon­strated advan­tages in cog­ni­tive func­tion with olive oil. These are con­sis­tent with other stud­ies that have shown a marked reduc­tion in neu­rode­gen­er­a­tion in mice with the use of olive oil polyphe­nols such as oleu­ropein.

There is now ample evi­dence to asso­ciate the MedDiet, which involves the reg­u­lar use of olive oil, with improved cog­ni­tive func­tion and lower inci­dence of AD. The authors of this study are cor­rect in cit­ing the paucity of data on the health prop­er­ties of other oils which are so often pro­moted as pos­si­ble alter­na­tives to olive oil.”

While canola oil boasts a cheaper price than olive oil, it could be costly in terms of harm­ful effects on the mind and body. The study, which was pub­lished in the jour­nal Scientific Reports, shows that health claims attrib­uted to canola oil don’t have merit.


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