THE TAKEAWAY: Industrial seed oils aren't toxic by nature, but high-heat processing and oxidized restaurant fry oil present legitimate metabolic concerns.

Seed oils like canola, soybean, and sunflower are rich in omega-6 polyunsaturated fatty acids (PUFAs), primarily linoleic acid. Critics claim linoleic acid drives systemic inflammation, but clinical human trials consistently show that replacing saturated fats with unsaturated seed oils reduces LDL cholesterol without elevating inflammatory biomarkers like hs-CRP. The real issue arises when seed oils are repeatedly heated in commercial deep fryers, forming toxic lipid peroxides and aldehyde byproducts. The fix isn't panicking over home-cooked seed oils—it's limiting ultra-processed and repeatedly fried foods.