Liquid Gold: How Olive Oil May Help Protect the Brain, According to Science

For thousands of years, olive oil has been a cornerstone of cooking and culture across the Mediterranean and North Africa, prized as much for its flavour as for its reputation as a healthful food. In kitchens from Morocco to Greece, it has long been treated as a kind of liquid gold.

Now, modern science is lending fresh weight to that ancient wisdom. A growing body of research suggests that this humble oil may do far more than enrich a meal, and one major study in particular has drawn attention to its possible role in protecting the brain. This article looks at what that research found, and why.

A landmark study

One of the most striking pieces of evidence came from a large study carried out by researchers at Harvard. According to reports, the findings were published in the journal JAMA Network Open in May 2024 and drew on data from a remarkably large and long running group of participants.

The scale of the research lends it considerable weight. Reports indicate that the study followed some 92,383 adults over a period of 28 years, tracking their diets and health outcomes over almost three decades, a span long enough to reveal patterns that shorter studies can easily miss.

Half a tablespoon a day

The headline finding was both simple and remarkable. According to reports, people who consumed at least 7 grams of olive oil each day, roughly half a tablespoon, were about 28 percent less likely to die from dementia than those who never or only rarely used it in their cooking.

That is a substantial difference for such a modest daily amount. It suggests that a small, easily achievable change to the diet, adding a little olive oil to everyday meals, could be associated with a meaningfully lower risk of one of the most feared conditions of later life.

A benefit of its own

Perhaps the most intriguing aspect of the findings is that the benefit appeared to hold on its own. Reports note that the link between olive oil and lower dementia related death remained even after accounting for the overall quality of people's diets, suggesting a protective effect specific to the oil itself.

Some reports went further, noting that even small swaps seemed to matter. Replacing a daily teaspoon of margarine or mayonnaise with olive oil was, by some estimates, associated with a reduction of roughly 8 to 14 percent in the risk of dying from dementia, hinting at the value of simple substitutions.

Why olive oil may help

Scientists have proposed several reasons why olive oil might benefit the brain. According to reports, it is rich in monounsaturated fats as well as compounds with antioxidant properties, including vitamin E and polyphenols, which are thought to have anti-inflammatory and neuroprotective effects.

Inflammation and oxidative stress are believed to play a part in the damage that underlies many forms of dementia. By helping to counter these processes, the compounds found in olive oil may, over many years, contribute to keeping the brain healthier for longer, though the exact mechanisms are still being studied.

More than the brain

The brain is far from the only organ that may gain. Olive oil has long been associated more broadly with heart health and is a central pillar of the Mediterranean diet, a pattern of eating that reports have repeatedly linked with longer life and lower rates of chronic disease.

For countries such as Morocco, where olive oil is woven into daily cooking, these findings carry a reassuring message. A food that is already deeply rooted in local tradition may also be quietly supporting the long term health of those who consume it regularly as part of a balanced diet.

A word of caution

It is worth remembering, however, that studies of this kind show associations rather than firm proof of cause and effect. Olive oil is no magic cure, and it is best enjoyed as part of a varied, balanced diet. Even so, the evidence offers one more reason to reach for that bottle of liquid gold.