Should you swap butter for vegetable oil?

Dariush MozaffarianMD, DrPH · cardiologist and nutrition epidemiologist, Tufts

Yes. Use plant oils as your main added fat, replacing butter and other animal fats, with the best evidence for soybean, canola and extra-virgin olive oil.

What it rests onVegetable oils sit in the consume-more column of his priorities table at 2 to 6 servings a day, with the examples column naming soybean, canola and extra-virgin olive oil as the best-evidenced. His argument is about replacement rather than about fat: swapping saturated fat for polyunsaturated oils lowers risk, swapping it for refined starch and sugar does not. His own concordance table is finer-grained than his headline: soybean, canola and olive oil sit under general concordance with some remaining controversy, while corn, sunflower and safflower sit under substantial controversy.

Nina TeicholzPhD · investigative science journalist and author

The cap on saturated fat is not evidence-based and should be dropped, and the trials that tested replacing it with vegetable oils were largely null.

What it rests onShe reads the government replacement trials of the 1960s and 1970s, about 67,000 people with hard endpoints and a 29 mg/dl average fall in cholesterol showing compliance, as failing to show the expected mortality reduction, and holds that more than 20 reviews since 2010 have concluded saturated fats have no effect on major cardiovascular outcomes. Her stated conclusion is that caps on saturated fat 'are not warranted and should no longer be part of national dietary guidelines'. Her declared interest on that paper is book royalties; her declared financial support is none.