Olive Oil Helps Protect Thought Processes in Older Persons

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Thanks to a wealth of research about the health benefits of a Mediterranean diet, we know more about the nourishing properties of olive oil than ever before. This unique oil stands at the center of a Mediterranean diet, and its regular use in this diet has been shown to help lower risk of key chronic diseases, including heart disease, diabetes, and certain cancers.

One area that hasn’t received as much attention has been compromised brain function and impaired thinking ability in later life. The potential risk-lowering properties of olive oil with respect to later life problems like memory loss or thinking impairment has not been carefully examined-until now!

Researchers based at the Montpellier University in Montpellier, France looked at the dietary intake and memory/thought processes of 6,947 French citizens (all 65 years of age or older) living in three French cities (Bordeaux, Dijon, and Montpellier). Nine food categories were examined, including: meat and poultry, fish (including seafood), eggs, milk and dairy products, cereals (including bread and starches), raw fruits, raw vegetables, cooked fruit or vegetables, and pulses (legumes). All study participants also provided detailed information about their use of fats and oils, including, of course, olive oil. Once this dietary information had been obtained, olive oil use was broken down into three categories: no use at all; moderate use consisting of cooking use only; and intensive use consisting of cooking use combined with use in dressings. For the study group as a whole, 23% turned out to use no olive oil at all; 40% had moderate use (cooking only); and 37% had intensive use (for cooking but also in dressings).

Participants in the study not only provided the dietary information above, but also completed a series of cognitive tests. These tests included the Mini mental State Examination, the Benton Visual Retention Test, and the Isaacs Set Test. These neuropsychological tests were designed to measure different aspects of visual memory, verbal fluency, and overall cognitive function in the study participants.

Intensive use of olive oil (involving the use of olive oil in both cooking and dressings) was found to significantly lower the risk of visual memory loss and verbal fluency loss in these 6,947 study participants. In addition, these olive oil benefits were found to be independent of other dietary practices. Interestingly, however, participants making intensive use of olive oil were less likely to use butter, peanut oil, corn oil, sunflower oil, duck fat, or goose fat in their diet. The were also three times as likely to have fish at least twice a week and two times as likely to have three or more vegetable/fruits servings each day when compared with participants who used no olive oil.

Taken as a whole, these results suggest that regular use of olive oil-in and of itself-can help lower risk of later life problems with thinking and memory, but that overall diet composition can also be important, especially in the areas of fruit/vegetable intake and overall fat balance. We also cannot help but wonder about the difference in this study between “moderate” and “intensive” olive oil use. By defining “moderate” use as cooking only, the study researchers may have inadvertently lowered the likelihood of beneficial results for olive oil use. This definition of “moderate use” would preclude the use of unheated olive oil in the diet! We know from a variety of studies that many of the unique nutrients in olive oil are heat-sensitive. By defining “moderate use” as “cooking only,” these researchers may have made it impossible for the full benefits of these heat-sensitive nutrients to be realized in a “moderate use” olive oil-containing diet. Only in the “intensive use” diet would the full benefits of these heat-sensitive nutrients be present, since “intensive use” included the use of olive oil in dressings (many of which would presumably be consumed without heating of any kind).

The researchers speculated about two aspects of olive oil that might have contributed to the cognitive benefits demonstrated in their study. First was the unique fat composition of olive oil that features monounsaturated fats (MUFAs). MUFAs from olive oil may have helped to improve circulation in the brains of the participants, prevented unwanted inflammation in the nerve cells, or helped to balance immune function in a way that left the brain and nerves functioning in a more stable way. In addition, unique phytonutrients in the olive oil-including polyphenols like oleuropein-may have helped to provide antioxidant protection to the participants’ nerve cells and bloodstream. The study authors recommended follow-up in this area of olive oil intake and the mechanisms involved in its protection of cognitive function.

WHF Recommendations

It’s time to expand our thinking about the benefits of olive oil, and to recognize the ability of this food to help lower our risk not only for chronic diseases like heart disease and type 2 diabetes, but also for common later life problems with memory and thinking. Use of olive oil in cooking alone is not going to provide us with the maximum benefits! We need to include olive oil in dressings and sauces that do not require heating. In this way, we can lower the risk of damage to many of the unique nutrients found in olive oil, including polyphenols and other cell-protecting antioxidants. In fact, we believe that it is best to not even cook with olive oil (at temperatures higher than for sauce making) since there is too much risk to the integrity of its nutrients and therefore to its overall health impact. Additionally, it’s also important to make regular olive oil use part of an overall healthy diet that includes plenty of fresh fruits and vegetables and limited amounts of heavily processed oils or saturated animal fats.

One of our favorite ways to use olive oil is to drizzle it over steamed or Healthy Sauteed vegetables. In addition, it is the type of oil that we use when preparing salad dressings.

References

Berr C, Portet F, Carriere I et al. Olive oil and cognition: results from the three-city study. Dement Geriatr Cogn Disord. 2009;28(4):357-64. 2009.