Daily consumption of at least half a tablespoon of olive oil is associated with a 28% reduction in the risk of mortality linked to major neurocognitive disorder, finds a new study published by a Quebec researcher who is completing her studies postdoctoral studies at Harvard University.
This reduction was measured compared to rare or no consumption of olive oil. Furthermore, this observation was independent of the quality of the participants’ diet and their level of adherence to the Mediterranean diet, explained Anne-Julie Tessier.
“I find this to be a striking result of this study,” said M.me Tessier. In general, people who use olive oil for cooking or as a seasoning have a higher quality diet. But the association was found to be present independently of this factor. »
“Higher olive oil intake was associated with a lower risk of dementia-related death, regardless of the level of diet quality or regardless of the level of adherence to a Mediterranean diet. »
On the other hand, she adds, it is “interesting and important” to mention that the lowest risk was observed “among people who had the combo, i.e. an intake of olive oil and a level of quality of “higher diet”.
Mme Tessier and colleagues analyzed data between May 2022 and July 2023 from some 92,300 participants (two-thirds of whom were women) in the Nurses’Health Study and the Health Professionals Follow-Up Study. Both studies were conducted between 1990 and 2018.
The participants in these two gigantic studies completed a questionnaire every four years on their diet. Their olive oil consumption was divided into four categories: never or less than once a month; more than zero, but less than 4.5 grams per day; between 4.5 and 7 grams per day; and more than 7 grams (or half a tablespoon) per day.
Just over 4750 cases of dementia-related mortality were recorded during the 28-year follow-up. Consumption of at least seven grams of olive oil per day was associated with a 28% reduction in this mortality risk, compared to no or rare consumption, even when taking into account factors associated with the mode of eating. life or socioeconomic status.
Other analyzes have linked replacing five grams of margarine or mayonnaise with an equivalent amount of olive oil to an 8% to 14% reduction in the risk of dementia-related mortality. No benefits were seen if olive oil replaced butter or other vegetable oils.
“This association remained significant after adjusting for diet quality scores, including adherence to the Mediterranean diet,” the study authors write. These findings provide evidence to support dietary recommendations advocating the use of olive oil and other vegetable oils as a potential strategy for maintaining overall health and preventing dementia. »
It is possible that the consumption of olive oil reduces mortality due to dementia by improving vascular health, explains the study, since “several clinical trials confirm the effect of olive oil on reducing cardiovascular diseases by improving endothelial function, coagulation, lipid metabolism, oxidative stress, platelet aggregation and decreasing inflammation.
“Certain antioxidant compounds present in olive oil, particularly in extra-virgin olive oil which is higher in polyphenols (…) can cross the blood-brain barrier and there could be a direct effect in this way on the brain , that’s a hypothesis,” added Mme Tessier.
It’s important to note that the study shows an association between olive oil and reduced risk of death, not causation.
It should also be noted that subjects belonging to the group with the highest olive oil consumption also had better diet quality, greater alcohol consumption, were more physically active and less likely to smoke ― all Factors that may impact cognitive decline or dementia.
Further studies will now be necessary to better understand the protective effect of olive oil. But because dementia-related problems can set in several years before symptoms first appear, there’s nothing wrong with taking some precautions, Ms.me Tessier.
“There is definitely no such thing as a superfood,” she said. Olive oil should not be considered a one-stop solution for preventing dementia. But I believe that Canada’s Food Guide recommends the use of healthy fats like olive oil, and I believe that these results support those already established recommendations. »
The findings of this study were published by the medical journal JAMA Network Open.
reference: www.lapresse.ca