Avocados may help 'keep you young'
25 April, 2012
ISLAMABAD: Avocados could help fight ageing and several diseases as they bolster cells' power centres against harmful free radicals, say scientists.
A number of environmental factors - such as pollution, cigarette smoke and radiation - can turn the oxygen molecules found in mitochondria, the power plants of cells, into free radicals.
These unstable molecules destroy virtually all the normal molecules forming cells, such as lipids, proteins and even DNA, by turning them into free radicals, too.
This destructive phenomenon is associated with aging and occurs in a variety of diseases, including hypertension and diabetes, which represent major challenges for health systems due to their great social and economic costs.
Many studies of antioxidants in vegetables and fruits, such as carrots and tomatoes, have been completed with few encouraging results.
"The problem is that the antioxidants in those substances are unable to enter mitochondria," said Christian Cortes-Rojo, a researcher at Universidad Michoacana de San Nicolás de Hidalgo in Morelia, Michoacan, Mexico.
"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."
But Cortes-Rojo is prepared to reveal the first research results showing the protective effects of avocado oil against free radicals in mitochondria.
The research team used yeast cells – those used in wine and beer production – to examine avocado oil's properties.
"The reason why we have chosen yeast," explains Cortés-Rojo, "is that (a) this microorganism is easier to study than other biological models due to its relative simplicity and (b) because studies our group published in 2009 and 2011 found that yeast mitochondria are very resistant to free radicals due to the sort of fat that forms its envelope, which is highly resistant to oxidation.
"The same kind of fat can be found in avocado oil; but, in addition, avocados also contain some plant pigments that inhibit oxidation. That is why we decided to test whether these avocado properties could increase even more the yeast's resistance to mitochondrial oxidation."
The results of this research, he said, show that avocado oil allowed the yeast cells to survive exposure to high concentrations of iron, which produces a huge amount of free radicals, "even to higher levels to those found in some human diseases."
"These results could be attributed to the fact that avocado oil caused accelerated respiration in mitochondria, which indicate that the use of nutrients for producing energy for cell functions remains effective even in cells attacked by free radicals and that mitochondria itself could produce little amounts of damaging free radicals," he continued.
Cortés-Rojo emphasized that these findings reinforce the good reputation the avocado has when it comes to health maintenance.
He points to pioneering research by Mario Alvizouri-Muñoz, a doctor at the Morelia General Hospital, who demonstrated that avocado lowers the blood concentration of cholesterol and certain fats that are increased in diabetic patients and that may lead to stroke or heart attack.
"Our results are promising because they indicate that avocado consumption could improve the health status of diabetic and other patients through an additional mechanism to the improvement of blood lipids," he said.