A study by Ohio State University has found that oils high in a polyunsaturated omega-6 fatty acid known as linoleic acid could have a beneficial effect on health, reducing the risk of heart disease and diabetes.

The study looked at data taken from two previous studies which looked at 139 men and women. As part of the studies participants had their fat and muscle mass measured, and were also asked to fast for 12 hours before giving a blood sample so the team could measure the amount of linoleic acid in their red blood cells.

The team also measured blood levels of oleic acid, found in olive oil and other vegetable oils, and long-chain omega-3 fatty acids, found in fatty fish such as salmon and tuna, as well as testing for insulin resistance and inflammation markers connected with disease.

Linoleic acid more beneficial than olive oil?

The results showed that participants who had a higher level of linoleic acid also tended to have less heart-threatening fat between their vital organs, more lean body mass and less inflammation in the body. They were also less likely to suffer from insulin resistance, a precursor to diabetes.

Suprisingly, although levels of inflammation decreased as the levels of all three of the different fatty acids increased -- linoleic, oleic, and omega-3 -- higher levels of oleic acid or long-chain omega-3s were not associated with a leaner body composition or a decreased risk of diabetes risk.

Commenting on the results, lead researcher Martha Belury believes the findings on linoleic acid could be significant for not only preventing heart disease and diabetes, but also because a lower body mass in later life can promote a longer and more independent life.

However, as all participants lived around Columbus, Ohio, Belury also noted that a different population, for example a population which consumes more omega-3 rich fatty fish, could have shown different results. The results came from a group of participants who were considered slightly healthier on average than the general population, which could also have affected the findings.

Increase your intake with grapeseed oil

For those wanting to up their intake of linoleic acid to benefit from the health benefits seen in Belury's study, it might therefore not be as easy as it seems, with the team warning that low-cost cooking oils high in linoleic acid are becoming harder to find due to an industry push for plants that are modified to produce a higher yield of oleic acid rich oils. Oils once high in linoleic acid such as safflower, sunflower and soybean now often contain less than 20 percent of linoleic acid. However grapeseed oil is still an excellent source of linoleic acid, with Belury also recommending corn oil as another good source.

The research was published online in the journal Molecular Nutrition & Food Research.