July 24, 2023

expert reaction to unpublished conference abstract about olive oil and dementia

A conference abstract (not a published paper) presented at NUTRITION 2023 looks at olive oil intake and dementia risk.

Dr Duane Mellor, Registered Dietitian and Senior Lecturer, Aston Medical School, Aston University, said:

“This claim of a 28% lower risk does not appear to match the limited information in the abstract which suggests an association between olive oil intake and a 25% reduction in risk of fatal dementia. 

“It is important to note that this is not causal, as the authors point out, only an association and more research is needed.

“It also does to consider aside from a measure of diet quality in the limited information presented how they controlled for other risk factors aside from the APO E4 gene. So, it is possible that residual confounding from factors that could not be controlled may explain this finding. The authors claim replacing margarine and mayonnaise with olive oil could reduce risk; however, many people who did this would also change the food that it is being added to, which could increase vegetable, lentils, beans, peas, seeds and nut intake – all of which are linked to a healthy diet and reduced risk of conditions like dementia.

“We also need to remember that it is not just what we eat that helps maintain our brain function, it is how we eat – and remaining sociable around meal times and eating with others can benefit our mental health in the short term and cognitive function as we age.”

Prof David Curtis, Honorary Professor, UCL Genetics Institute, University College London (UCL), said:

“These findings are simply being reported at a conference and have not undergone peer-review so there has been no examination of the study by independent experts. We do not know whether the results will end up being published in a journal. If the study does eventually result in a published paper we do not know whether the published results will be the same as those now being presented or whether they may be different.

“This kind of observational study will often report an association between a factor and an outcome but that does not imply any causal relationship. There are many, many differences between people who consume olive oil and those who do not and it is never possible to fully account for all possible confounding factors. Another point to bear in mind is that about half of dementia is caused by vascular disease so that anything which improved cardiovascular health, such as not smoking, would be expected to reduce dementia risk. It has been shown that olive oil consumption is associated with better cardiovascular health so one would expect that it would also be associated with lower dementia risk.

“Without a full, peer-reviewed paper it is difficult to say whether this study adds much to our understanding of the links between diet, health and dementia risk.”

Abstract title: ‘Opting for Olive Oil Could Boost Brain Health’ was presented at the NUTRITION 2023 conference on Monday 24 July 2023.

This work is not peer-reviewed and there is no paper.

Declared interests

Prof David Curtis: “I declare no conflict of interest.”

Dr Duane Mellor: “No declarations of interest.”