Consuming half a tablespoon of the oil — a major component of the Mediterranean diet — every day was also credited with cutting the odds of dying from cancer or other conditions like Alzheimer’s.
And replacing fats such as butter, margarine and mayonnaise with olive oil may give even greater benefits, experts say.
Harvard University researchers examined data from almost 100,000 people gathered over the course of three decades.
Their study is the latest to tout the health benefits of the Mediterranean diet, which A-list celebrities like actress Penelope Cruz have raved about for years. A plethora of studies have linked it to better heart health.
Lead researcher Dr Marta Guasch-Ferré said: ‘Our findings support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils.
‘Clinicians should be counseling patients to replace certain fats, such as margarine and butter, with olive oil to improve their health.
‘Our study helps make more specific recommendations that will be easier for patients to understand and hopefully implement into their diets.’
The study, published in the Journal of the American College of Cardiology, used data from 60,582 women and 31,801 men.
All the participants worked in the health sector and didn’t have any cardiovascular disease or cancer when the study began in 1990.
They were quizzed every four years on their food consumption asking how often they consumed specific foods, and the type of fats and oils they used in cooking, over the previous year.
Over the course of 28 years measured in the study, there were 36,856 deaths among the participants.
Scientists then compared the data on people who ate more than 7g of olive oil per day, the equivalent of about half-a-tablespoon, with those who ate 4.5g or less.
They found the people who ate more olive oil had a 19 per cent lower risk of cardiovascular death such as from a heart attack or stroke.
Similar benefits were also observed for cancer and respiratory disease, with up to a 18 per cent lower risk of death. The odds of dying from a neurodegenerative disease fell by 29 per cent.
But it should be noted that participants with higher olive oil consumption were often more physically active or of Southern European or Mediterranean ancestry. And they were also less likely to smoke and eat more fruit and vegetables.
It means some of the health differences may not just be from olive oil consumption alone.
But Dr Guasch-Ferré said the researchers had compensated for these differences in their findings.
‘It’s possible that higher olive oil consumption is a marker of an overall healthier diet and higher socioeconomic status,’ she said.
‘However, even after adjusting for these and other social economic status factors, our results remained largely the same.’
Heart disease is one of the biggest killers in both the UK and the US.
They kill 160,000 Britons each year, the equivalent to one death every three minutes, according to the British Heart Foundation.
And the US Centre for Disease Control estimates 695,000 Americans die from heart disease every year, equivalent to one death every 36 seconds.
Additionally, the scientists also found swapping out other fats for olive oil resulted in a general reduced risk of death.
They found replacing 10g per day of fats, such as margarine, butter, and mayonnaise, with olive oil was associated with an 8-34 per cent lower risk of total and cause-specific mortality.
However, the same benefits were not seen for other vegetable oils.
Independent experts welcomed the study but said more research needed to be done.
Professor Susanna Larsson, an expert in epidemiology at the Karolinska Institutet in Stockholm, said scientists needed to pin down the exact nature of olive oil’s protective powers.
‘What is the amount of olive oil required for a protective effect? More research is needed to address these questions.’
Olive oil is key component of the Mediterranean diet, which has been linked to a plethora of health benefits in part due to its antioxidative and anti-inflammatory properties.
The NHS has noted the diet carries numerous health benefits.
Eat at least 5 portions of a variety of fruit and vegetables every day. All fresh, frozen, dried and canned fruit and vegetables count
** Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain
** 30 grams of fibre a day: This is the same as eating all of the following: 5 portions of fruit and vegetables, 2 whole-wheat cereal biscuits, 2 thick slices of wholemeal bread and large baked potato with the skin on
** Have some dairy or dairy alternatives (such as soya drinks) choosing lower fat and lower sugar options
** Eat some beans, pulses, fish, eggs, meat and other proteins (including 2 portions of fish every week, one of which should be oily)
** Choose unsaturated oils and spreads and consuming in small amounts
** Drink 6-8 cups/glasses of water a day
** Adults should have less than 6g of salt and 20g of saturated fat for women or 30g for men a day
Read more: ** https://dx.doi.org/10.1016/j.jacc.2021.10.041