These are particularly common inside mitochondria, the tiny powerhouses in our cells that turn the food we eat into energy.

Many antioxidant chemicals in vegetables and fruits such as carrots and tomatoes can mop up free radicals, but they cannot make their way inside mitochondria.

Those in avocados can, the American Society for Biochemistry and Molecular Biology’s annual conference heard. Researcher Christian Cortes-Rojo said, “The problem is that the antioxidants in [other] substances are unable to enter mitochondria.

"So free radicals go on damaging mitochondria, causing energy production to stop and the cell to collapse and die.

"An analogy would be that, during an oil spill, if we cleaned only the spilled oil instead of fixing the perforation where oil is escaping, then the oil would go on spilling, and fish would die anyway.”

Unstable free radicals are natural waste products of metabolism but may be generated in greater numbers due to factors such as pollution, tobacco smoke and radiation.

They wreak havoc in the body, triggering chain reactions that destroy cell membranes, proteins and even DNA.

The phenomenon is one of the prime drivers of ageing and believed to play a major role in damage to arteries and cancer.

The researchers found avocado oil allowed yeast cells to survive exposure to high concentrations of iron -- an element that produces “huge amounts” of free radicals.

"We’ll need to confirm that what has been observed in yeasts could occur in higher organisms, such as humans,” said Mr Cortes-Rojo, from the University Michoacana de San Nicolas de Hidalgo in Mexico.

Avocado oil is similar in composition to olive oil, consumption of which is associated with unusually low levels of chronic disease in some Mediterranean countries, and Cortes-Rojo said his discovery could mean avocado oil becoming ‘the olive oil of the Americas’.

Previous research conducted in Mexico, the world’s largest avocado producer, has shown that the fruit lowers blood levels of cholesterol, and certain fats linked to diabetes.

 From the April 23, 2012, Prepared Foods’ Daily News