FROM salad dressings to bread dips and roasted veg, olive oil has long been celebrated as a kitchen staple with powerful health benefits.
A cornerstone of the Mediterranean diet, olive oil was hailed as an elixir of youth and health in ancient Greece.
And swathes of new research suggest it lives up to the hype, slashing the risk of disease and early death.
But scientists now believe oleic acid, a common fat found in olive oil, helps fat cells grow and multiply, potentially driving weight gain faster than other oils.
US researchers behind the study urged home cooks to “moderate” their olive oil intake, “especially high-risk individuals.”
“If someone is at risk for heart disease, high levels of oleic acid may not be a good idea,” they wrote.
This comes amid growing concern from experts who warn that guzzling too much of the golden liquid may raise cholesterol and increase the risk of heart disease.
In the new study, published in Cell Reports, scientists fed mice diets enriched with specific fats found in olive oil, coconut oil, lard, peanut oil, milk, and soybeans.
They found oleic acid activated a protein called AKT2 while suppressing another, LXR, triggering the formation of new fat cells.
“You can think of the fat cells as an army,” said study co-author Dr Michael Rudolph, assistant professor of biochemistry and physiology at the University of Oklahoma.
“When you give oleic acid, it initially increases the number of ‘fat cell soldiers’ in the army, which creates a larger capacity to store excess nutrients,” he added.
“This means that over time, obesity can occur, which can then lead to cardiovascular disease or diabetes if not controlled,” he said.
The researchers admit most people don’t eat olive oil in isolation, they’re mixed into salads and burgers.
But diets high in oleic acid, especially from ultra-processed foods, could be bad news for the heart.
“I think the take-home message is moderation and to consume fats from a variety of different sources,” he said.
“Relatively balanced levels of oleic acid seem to be beneficial, but higher and prolonged levels may be detrimental.
“If someone is at risk for heart disease, high levels of oleic acid may not be a good idea.”
For years, olive oil has been the go-to fat for dietitians and chefs alike.
Just last year another, US study emerged suggesting more than half a tablespoon of olive oil a day can cut Alzheimer’s risk by 28 per cent.
Meanwhile, an NHS trial found that oleic acid could help treat incurable brain tumours.
Celebs and influencers also can’t get enough of it.
Dua Lipa drizzles it on ice cream, and Kourtney Kardashian swears by it as a hair treatment.
Top chef Jamie Oliver is known for generously pouring olive oil over his dishes.
And biohacker Bryan Johnson drinks spoonfuls of olive oil each morning and sells his own brand as part of a pricey anti-ageing plan.
‘Olive oil isn’t something to demonise’
Despite the new findings, Robert Hobson, nutritionist at Healthspan and author of Unprocess Your Family Life, said olive oil is still the “best” choice for everyday cooking, because of its “health benefits”.
“It helps lower cholesterol, because it increases good cholesterol, but lower bad cholesterol,” he told Sun Health.
Cholesterol is a substance found in fats that’s needed to build healthy cells, but can increase the risk of heart disease if levels are too high.
“You’ve also got things like pleocanthal, which is that peppery taste in olive oil, and that helps to reduce inflammation as well. “
But people should use it “sparingly” because it is a fat, he said.
“You only need a teaspoon in a non-stick pan to cook food,” he explained.
“And I think people do chuck it in very liberally.
“While it’s good for you, obviously, you can have loads of it, then it’s going to encourage weight gain.”
He added: “People in the Mediterranean have been using it for hundreds and hundreds of years and we recommend that diet as one of the healthiest diets.
“I just think it’s not a food that we should be demonising.”
How to follow the Mediterranean diet
The Mediterranean diet is rich in plants – think nuts, seeds, fruits, vegetables, whole grains, and legumes.
The main fat is olive oil (usually extra virgin), and the diet usually includes moderate intake of fish, poultry, dairy, eggs and alcohol.
Other meat, sweets, beer, processed foods and refined grains are kept to a minimum.
Features of a Mediterranean lifestyle that may also benefit a person’s health include sharing meals with others, consuming red wine and flavouring foods with herbs and spices rather than salt.
A typical day following a Mediterranean diet may look like this:
BREAKFAST
Yoghurt with granola, banana, figs, almonds, sunflower seeds and peanut butter
LUNCH
Chicken salad with chickpeas, mozzarella, tomato, cucumber, kale, spinach, onion and a slice of wholemeal bread and extra virgin olive oil
DINNER
Grilled sea bass with brown rice, rocket and a glass of red wine
SNACKS
Apple and almond butter, hummus and crackers and boiled egg
