Olive oil on salad may save your life
Olive oil found to protect the heart against damage from air pollution and lower blood pressure
A drizzle of olive oil on your salad can protect your heart against the damage caused by air pollution and help to lower blood pressure, scientists have found.
Researchers have shown that eating the equivalent of two thirds of a teaspoon of olive oil every day can reduce the effect of air pollution on the heart.
A separate study has also shown that olive oil can lower blood pressure when eaten with certain vegetables.
Olive oil has long been lauded as the reason why Mediterraneans live longer, healthier lives and scientists are now unpicking the biology behind this.
British scientists have found that a diet rich fats like olive oil and nitrate rich vegetables like lettuce can lower blood pressure.
The diet typically contains ‘good’ unsaturated fats found in olive oil, nuts and avocados with vegetables such as spinach, celery and carrots that contain high levels of nitrates.
When the two substances are combined they form nitro fatty acids.
Experiments on mice found nitro fatty acids lower blood pressure.
Professor Philip Eaton, Professor of Cardiovascular Biochemistry at King’s College London, said: “The findings of our study help to explain why previous research has shown that a Mediterranean diet supplemented with extra-virgin olive oil or nuts can reduce the incidence of cardiovascular problems like stroke, heart failure and heart attacks.”
The findings were published in the journal Proceedings of the National Academy of Sciences.
Dr Sanjay Thakrar, Research Adviser at the British Heart Foundation, which co-funded the research, said: “This interesting study goes some way to explain why a Mediterranean diet appears to be good for your heart health. The results showed a way in which a particular compound could combat high blood pressure, which is a major risk factor for heart disease.
“However, more work is necessary as these experiments were conducted in mice and this compound could also be having its effect through other pathways.”
Meanwhile another study, conducted by American government scientists found that olive oil supplements can reduce the health impact of air pollution.
Exposure to high levels of air pollution is linked to an increased risk of heart disease, stroke and asthma.
Microscopic particles from diesel engines, for example, increase inflammation and cause blood vessels to harden, increasing blood pressure and the risk of clots.
The findings, based on 42 healthy adults who were exposed to controlled levels of air pollution, were presented at the American Thoracic Society International Conference.
The subjects were given three grams of olive oil per day or fish oil or neither for four weeks before they were exposed to two hours of filtered air. The following day they were exposed to two hours of polluted air.
Their blood vessels were measured using ultrasound before, immediately after and 20 hours after the exposures.
There was significant narrowing of the blood vessels immediately after exposure to the air pollution in the group who did not take supplements and the group that took fish oil supplements.
However there was no significant narrowing in the group that took olive oil.
In addition other biological changes were noted. The group that took olive oil showed an increase in a protein that breaks down blood clots after exposure to the air pollution. Blood clots can cause a heart attack when they lodge near the heart or a stroke when in the brain.
Dr Haiyan Tong, a research biologist with the United States Environmental Protection Agency, said: “Our study suggests that use of olive oil supplements may protect against the adverse vascular effects of exposure to air pollution particles.
“If these results are replicated in further studies, use of these supplements might offer a safe, low cost, and effective means of counteracting some of the health consequences of exposure to air pollution.”
A third study has found that pregnant women exposed to air pollution during their second trimester are at greater risk of having children with asthma.
It was known that air pollution damages the lungs of the developing baby but it has now been found that weeks 12 to 24 are the peak period.
The findings, from Icahn School of Medicine and Mount Sinai in New York, were also presented at the American Thoracic Society International Conference.
The study included 430 children followed from birth to age seven.