Oils rich in linoleic acid - a type of polyunsaturated omega-6 fatty acid - can reduce heart disease and diabetes risks, a study found.
Researchers from the Ohio State University analyzed two past studies involving 139 men and women. The participants' fat content and muscle mass were measured. To get the linoleic acid levels in their red blood cells, they fasted for 12 hours before providing blood samples.
Oleic acid is found in olive oil and other vegetable-based oils while omega-3 fatty acids are found in fatty fish like tuna. Levels of oleic, linoleic, and fatty acids in the participants' blood samples were measured. Disease-related inflammation markers and insulin resistance were also documented.
Findings showed that the people with higher linoleic acid levels had low levels of heart-threatening fat found between vital organs. These participants also had less inflammation and a leaner body mass. Moreover, they have lower chances of suffering from insulin resistance.
As the levels of the three fatty acids surged, inflammation decreased. However, high levels of omega-3 fatty acids and oleic acid were not linked to lower risks of diabetes and lean body mass. Lead researcher Martha Belury suggests that linoleic acid's benefits go beyond the prevention of diabetes and heart disease.
"This finding could have obvious implications in preventing heart disease and diabetes, but also could be important for older adults because higher lean body mass can contribute to a longer life with more independence," said Belury an Ohio State University professor.
Belury noted that all the participants were considered somewhat healthier compared to the average population. A different study population could have yielded different results.
Unfortunately, as much as we want to increase the general consumption or even a switch to the use of linoleic acid, it is becoming harder to find. Food manufacturers seek plant-based oils that are rich in oleic acid.
"Vegetable oils have changed. They're no longer high in linoleic acid," said Belury.
Linoleic acid needs to be hydrogenated (solidified) for processed food. When this happens, linoleic acid has higher chances of converting into trans fat compared to oleic acid.
Normally, oils like soybean, sunflower and safflower contain less than 20 percent of the fatty acids. Today, oils contain less linoleic acid, as shown in food labels. Belury also confirmed this hypothesis in her laboratory tests.
To date, grapeseed oil is a good source of linoleic acid, making up at least 80 percent of the oil's fatty acids. Corn oil is another good source. The research was published in the Molecular Nutrition & Food Research journal.
