Margarine was a darling toast-topper during the low-fat craze of the 1990s. Made from plant oils like palm oil, canola oil, and soybeans, it was marketed as a "healthier" alternative to animal fats.

But margarine used to include trans fat. Harvard researchers estimate that during the heyday of artificial trans fats in the 1990s, their presence in our food supply led to roughly 50,000 preventable deaths every year in the US. The FDA rolled out a near-universal ban on artificial trans fats in 2018, and most margarines today are trans-fat free.

But butter alternatives are highly processed, and vegetable oils that are lab-heated to prevent spoilage, like those in margarine, can be serious drivers of disease. Often, a key ingredient in margarine is palm oil, which is not nearly as good for our hearts as monounsaturated fats that are in a liquid state at room temperature, like olive oil. Monounsaturated fats can lower bad cholesterol levels and keep our immune systems humming with Vitamin E, making them a healthier choice.