Mayo is mostly oil. Usually the cheapest oil the manufacturer can source. That oil is highly refined, which usually involves dissolving ground up seeds in some

Mayo is mostly oil. Usually the cheapest oil the manufacturer can source. That oil is highly refined, which usually involves dissolving ground up seeds in some solvent like hexane, then some high heat process to extract and de-odor the oil. Given that seed oils usually comprises polyunsaturated oils which due to their multiple double bonds are more reactive, the chemical processes probably tend to create more undesirable by products. I mean, unless you prefer to drink the cheapest cooking oil you can find in your supermarket, you might want to avoid the mayo as well. (disclaimer: I occasionally drink EVOO directly)