Even healthy-seeming oils like avocado oil can break down into harmful stuff when heated because they have too much of a fragile kind of fat.
Scientific Claim
Oils with polyunsaturated fatty acid content exceeding 10% are susceptible to thermal oxidation during cooking, generating cytotoxic aldehydes and lipid peroxides.
Original Statement
“Avocado oil is about 70% monounsaturated fat. Now, this is a moderately stable fat, but it still contains a relatively significant amount of polyunsaturated fat, roughly 13 to 15%. This is the type of fat that's most vulnerable to oxidization and heat damage.”
Context Details
Domain
nutrition
Population
unspecified
Subject
oils with >10% polyunsaturated fatty acids
Action
undergo thermal oxidation
Target
generation of cytotoxic aldehydes and lipid peroxides
Intervention Details
Evidence from Studies
Supporting (2)
The study heated common cooking oils and found they produced harmful chemicals when fried — exactly what the claim says happens when oils with lots of polyunsaturated fats are cooked at high heat.
Comparison of Furans Formation and Volatile Aldehydes Profiles of Four Different Vegetable Oils During Thermal Oxidation.
The study heated different cooking oils and found that oils with lots of polyunsaturated fats (like soybean and perilla oil) produced harmful chemicals when cooked, just like the claim says.