A new study published by researchers at Stanford University School of Medicine has found evidence connecting the consumption of olive oil’s most prevalent fat with longevity in worms.
“Our interest came from aging,” lead researcher Katharina Papsdorf told Olive Oil Times. “We want to understand what drives aging and how can we regulate aging.”
We found that oleic acid consumption increases the lipid droplets. When we feed the worm oleic acid, the lipid oxidation is reduced. And generally, lipid oxidation is bad for lifespan and increases with age.
Since it is well-known that diets rich in olive oil and nuts, such as the Mediterranean diet, are associated with populations that live longer, Papsdorf wanted to study the cellular mechanisms behind this connection to see the link between the type of fat and longevity.
The study built on previous research that found that worms with more monounsaturated fatty acids (either acquired through self-production or diet) lived longer than worms without, with the strongest effect seen with oleic acid. About 70 percent of the total fat content of olive oil is comprised of oleic acid.See Also:Olive Oil Research News
Papsdorf and the team of genetics researchers found that worms fed a diet rich in oleic acid lived 33 percent longer than worms fed a standard diet.
They also observed that oleic acid consumption increased the number of peroxisomes and lipid droplets in the intestine of the worms. The quantity of both organelles – the ‘organs’ of a cell – is higher in younger animals and naturally decreases over time.
Lipid droplets, which store fat, proved to be a predictive factor of longevity. The droplets protect from damage due to lipid oxidation, which can lead to cell death.
However, the relationship between longevity and peroxisomes, which have a range of functions related to lipid synthesis and degradation and the detoxification of reactive oxygen species, remains largely unknown.
“We found that oleic acid consumption increases lipid droplet numbers,” Papsdorf said. “When we feed the worm oleic acid, lipid oxidation is reduced. And generally, lipid oxidation is bad for lifespan and increases with age.”
She added that the number of lipid droplets in individual worms allowed researchers to predict the animal’s lifespan; worms with more lipid droplets lived longer than those with fewer.
For the study, Papsdorf used a population of genetically-identical Caenorhabditis elegan, a species of roundworm with a short lifespan, that lived on the same plate and in the same controlled environment.
She said the worms allowed the researchers to track molecular changes that occurred with the change in diet to determine how these changes affected lifespan.
“At two points in their lives, I separated them into populations of high and low lipid droplet numbers,” Papsdorf said. “I saw that the ones that had more lipid droplets lived significantly longer. So there’s something beneficial to having more fat storage in the intestine.”
However, she added that the reasons why the increased number of lipid droplets resulted in longer lifespans required further study. Papsdorf hypothesized that they could serve as energy reservoirs or be beneficial for capturing harmful molecules.
These latest findings add further nuance to understanding how fatty acids relate to health. Previous research shows that lipid droplets can be harmful, depending on where they develop.
“There might be something about the tissue or the organ in which the lipid droplets are located which makes them beneficial in some cases and detrimental in others, but we don’t know why yet,” Papsdorf said.
Anne Brunet, a professor of genetics at Stanford University Medical School and senior author of the study, told the university news center that “there is still a lot of research to be done to learn whether and how these findings apply to humans.”