Lately it seems we have been reading a lot about promising scientific studies that suggest that, in addition to being protective of cardiovascular and other chronic diseases, the Med diet may protect against cognitive decline. For instance, there was this report stemming from the Harvard School of Public Health, and another study that specifically looked at the benefits of extra virgin olive oil in fighting Alzheimer’s.
So I was surprised to see an article from ScienceAlert.com in my newsfeed last week with the title, “20-Year Study Reveals That a Famed Diet Doesn’t Do Much to Reduce Dementia Risk.” It reported that a newly published Swedish study suggests that “[a] ‘Mediterranean diet’ does not lower the odds of developing dementia.”
A review of the source material, however, showed that the reporting was materially inaccurate. The Swedish study actually found that a “modified Mediterranean Diet” did not reduce dementia risk. What did the authors mean by “modified?” Since olive oil consumption in Sweden is very low, the researchers swapped out olive oil consumption for any vegetable oil in determining adherence to the diet.
A Med diet without olive oil? When I asked Tassos C. Kyriakides, Ph.D. at the Yale University School of Public Health about this, he cut to the chase: “I don’t think it should even be called a Mediterranean diet if it does not include the main food item!” In fact, the Swedish study’s authors themselves cautioned “that using vegetable oils instead of olive oil could be a limitation” of the “modified” Med diet they chose to study. [Note: just before publishing this, another article hit my inbox making the similar claim that the Swedish study “found no link between Mediterranean diet adherence and lower dementia incidence,” similarly failing to point out that it was a modified Med diet without olive oil.]
So the findings of the Swedish study are actually supportive of the benefits of olive oil as opposed to other vegetable oils. If a traditional Med diet that includes olive oil (especially extra virgin olive oil) as its principle fat appears to protect cognitive function—as the Harvard study found, but a modified Med diet without olive oil—such as what was considered in the Swedish study—does not, this could speak volumes about the critical role olive oil plays in the Med diet’s protection against cognitive decline.
