Is butter more stable than plant oils when cooked at high heat?

We reviewed 37 assertions that support this idea, and none that contradict it. These assertions focus on how butter behaves chemically when heated — particularly how it resists the breakdown of fats into potentially harmful oxidized compounds, which can form when oils are exposed to heat, air, and light. Refined plant oils, even if they’re marketed as healthy, often contain high levels of polyunsaturated fats that are more prone to oxidation under high heat. Butter, with its higher saturated fat content, tends to remain more chemically unchanged during cooking.

It’s important to note that this doesn’t mean butter is “better” or “healthier” overall — we’re only looking at stability during heating. We also don’t have data on other factors like smoke point, flavor changes, or long-term health effects from consuming oxidized fats. The evidence we’ve reviewed is limited to this one specific comparison: oxidized lipid production during high-heat cooking.

For everyday cooking, this means if you’re frying or searing at high temperatures, butter might hold up better than some refined oils in terms of chemical stability. But choosing a cooking fat still depends on many other factors — taste, nutrition, and how often you cook at high heat.