Incorporating olive oil into your diet could play a role in reducing the risk of dying from dementia, according to a new study recently presented at Nutrition 2023, the prestigious annual meeting of the American Society for Nutrition.
As Alzheimer’s disease and other forms of dementia continue to afflict millions worldwide, the findings offer hope that simple dietary changes could hold the key to preventing or slowing the progression of these devastating conditions.
“Our study reinforces dietary guidelines recommending vegetable oils such as olive oil and suggests that these recommendations not only support heart health but potentially brain health as well,” Lead researcher Anne-Julie Tessier, RD, PhD—a postdoctoral fellow at the Harvard T.H. Chan School of Public Health—said in a statement.
“Opting for olive oil, a natural product, instead of fats such as margarine and commercial mayonnaise is a safe choice and may reduce the risk of fatal dementia,” Tessier said.
Olive oil and dementia
Dementia encompasses a range of conditions in which impairments in thinking or memory impact daily activities. Alzheimer’s, the most common form of dementia, affects approximately 5.7 million Americans and remains a progressive and fatal disease.
The study is the first of its kind to investigate the link between diet and dementia-related death. Here, researchers analyzed dietary questionnaires and death records from more than 90,000 Americans over a span of three decades, during which 4,749 participants succumbed to dementia.
The findings revealed that individuals who consumed more than half a tablespoon of olive oil daily experienced a remarkable 28 percent lower risk of dying from dementia compared to those who rarely or never incorporated olive oil into their diets.
Even the simple substitution of just one teaspoon of margarine or mayonnaise with an equivalent amount of olive oil per day was associated with an 8 to 14 percent lower risk of fatal dementia.
Is olive oil good for you?
Previous research has hinted at the benefits of olive oil, which tends to be part of healthier overall diets when used in place of processed or animal fats. “Research shows that saturated and trans fats found in dairy products, meats, pastries, and fried foods can increase the risk for cognitive decline,” Stephanie McBurnett, RDN, LDN, a dietician with the Physicians Committee for Responsible Medicine, tells VegNews, “[However], plant-based foods help protect brain health due to being low in saturated fat, high in fiber, and have anti-oxidative effects.”
For this particular study, Tessier pointed out that the relationship between olive oil and dementia mortality risk remained independent of overall diet quality, suggesting unique and direct brain health benefits.
“Some antioxidant compounds in olive oil can cross the blood-brain barrier, potentially having a direct effect on the brain,” Tessier said. “It is also possible that olive oil has an indirect effect on brain health by benefiting cardiovascular health.”
Studies in the past have already linked higher olive oil consumption to a reduced risk of heart disease, and incorporating olive oil as part of a Mediterranean dietary pattern has shown promise in protecting against cognitive decline.
Nevertheless, Tessier stressed that the research is observational and does not establish olive oil as the definitive cause of the reduced risk of fatal dementia. Additional studies, including randomized controlled trials, will be necessary to confirm these effects and determine the optimal quantity of olive oil for maximum benefits.
Plant-based foods for brain health
Similarly, other studies have found that certain compounds in plant foods have a positive effect on brain health.
A study published in the American Academy of Neurology’s journal, Neurology, found that people who eat or drink more foods with antioxidant flavonols, which are found in fruits and vegetables as well as tea and wine, may have a slower rate of memory decline.
Another study published in the journal eLife found that a diet high in dietary polyphenols, which are naturally occurring compounds often found in plant-based foods, could help to protect the body from oxidative stress, offering a positive impact on brain health.
McBurnett explains that eating certain plant foods offers certain brain benefits, such as anthocyanins found in blueberries, resveratrol found in purple foods, as well as vitamin E-rich foods such as nuts and seeds, leafy greens, and whole grains.
“By eating all the colors of the rainbow, you’ll harness the power of plants,” McBurnett says.
“Studies have also found a connection between soy products and the reduced risk of dementia. This is most likely due to soy’s ability to improve arterial stiffness and promote better cardiovascular health,” McBurnett adds.
Lifestyle and dementia risk
Overall, the new study aligns with existing dietary recommendations and strengthens the evidence supporting the replacement of animal-based products with plant-based options such as olive oil to support a healthy diet.
As the scientific community continues to explore potential interventions for dementia, this study highlights the significant impact that simple dietary changes may have on mitigating the risk of this devastating condition. In addition to a healthy diet, McBurnett also points to other lifestyle factors that could lower the risk of dementia.
For example, while plant foods offer antioxidants, polyphenols, vitamins, and minerals to promote better serum cholesterol levels and help clear protein plaques in the brain, exercise improves cardiovascular health and maintains brain size as we age, while getting enough sleep has shown to decrease inflammation—which are all linked to a lower risk of dementia.
“The data indicates that attention to optimal lifestyle is essential to promote cognitive health,” McBurnett says.