A novel peer-reviewed document published in Nutrition Today has dispelled myths surrounding seed oil intake — finding that seed oil-derived linoleic acid can actually reduce cardiovascular disease risk.
This follows a study from November 2024, finding the benefits of omega-6 consumption on heart health and type II diabetes risk, as well as cancer risk.
Linoleic acid is the main polyunsaturated fatty acid found in seed oils, and prior studies have revealed that it has no impact on markers of oxidative stress or inflammation.
This challenges the beliefs that seed oils — specifically the omega-6 fatty acids they contain — directly contribute to cardiovascular health problems.
In this manuscript, scientists Dr Kristina S. Petersen, Dr Mark Messina and Dr Brent Flickinger took a deep dive into the literature surrounding seed oil intake, finding:
- Most randomised human clinical trials found that linoleic acid had no impact on markers of oxidative stress
- Randomised trials show that omega-6s such as linoleic acid don't increase inflammation
- Meta-analyses link higher linoleic acid intake to a reduced risk of cardiovascular disease, as well as adverse cardiovascular events
- Replacing saturated fat with polyunsaturated fat oils can lower blood cholesterol and cardiovascular disease risk, according to the randomised controlled trials assessed in the construction of this manuscript
"Linoleic acid is incorrectly claimed to cause inflammation because of its potential conversion to arachidonic acid — metabolites of which are thought to be pro-inflammatory. However, it is now well established that linoleic acid intake has a negligible impact on blood or tissue levels of arachidonic acid," says Kristina Petersen, lead author of the manuscript and associate professor, Department of Nutritional Sciences, Pennsylvania State University.
"In addition to cardiovascular disease, evidence indicates that linoleic acid may lower the risk of developing several chronic diseases like type 2 diabetes, liver disease and dementia."
Seed oil processing: addressing rumours
As well as discussing the health impacts of seed oil consumption, the manuscript also covers its processing steps, which have previously come under scrutiny.
During the extraction process, seed oil producers tend to use solvent hexane, which is evaporated and recovered from the oil upon heating.
However, after analysing oils available on the marketplace, the authors determined that the average member of the US public would have to consumer more than 100x more oil on average to ingest even the lowest safety limit of the substance.
Notably, seed oils are also a great source of vitamin E, a potent antioxidant that is strongly involved in immune functioning, vision and brain health.
Currently, the dietary guidelines outlined for the American population by both the WHO and the EFSA note that saturated fat consumption should total 10% of energy intake, while they recommend replacing these types of fat with polyunsaturated fats — which often come in the form of linoleic acid.
[This manuscript was funded by the Soy Nutrition Institute Global, with support from the United Soybean Board]