Margarine has gotten a bad rap for years, but a U.S. ban on partially hydrogenated oils may have made it a healthier choice than butter, a new study suggests.

Before the U.S. Food and Drug Administration banned such oils in 2018, margarine contained these oils, which are heavy in trans fats and raise bad ("LDL") cholesterol levels while lowering good ("HDL") cholesterol levels. Eating trans fats also increases the risk of heart disease, stroke and type 2 diabetes.

"Margarines are a better option than butter for heart health, with tub and squeeze margarines being the best options," said lead researcher Cecily Weber, a dietetic intern at the University of Minnesota School of Public Health, in Minneapolis.

The study team "also found that margarine and butter blend products contain less saturated fat and more unsaturated fat than regular butter," she added.

"This is a public health success story. It is now easier for [U.S.] consumers to make heart-healthy choices because they no longer need to worry about checking the labels of products to look for partially hydrogenated oils for trans fat, they can just know the products don't contain them," Weber said.

For the study, which had no funding from margarine makers, Weber and her colleagues examined the fatty acid content of 83 margarine and margarine-like and butter blends sold in the United States, comparing them with butter.

The investigators found that after the ban, margarine and butter blend products had substantially less saturated fat and cholesterol, compared with butter. These products also had no man-made trans fat.

The softer tub and squeeze tube margarines contained less saturated fat than stick margarines, which makes them the healthier choice among margarines, Weber noted.

"Stick margarines contain more saturated fat than tub or squeeze margarines, which allows them to be more firm at room temperature," she said. "However, for heart health, current dietary recommendations are to limit saturated fat intake."

Weber added that although margarines sold in the United States are healthier than they used to be, they should still be eaten in moderation.

"While margarines are a better option than butter for heart health, they should still be eaten sparingly, as they do still contain some saturated fat and have a high energy density; that is, they contain a high amount of calories per serving size," she explained.

The report was published online recently in the journal Public Health Nutrition.

Samantha Heller, a senior clinical nutritionist at NYU Langone Health in New York City, cautioned that instead of margarine or butter, the really healthier option is to use vegetable oils.

"Whether the spread comes from cows or chemists, it is the content of saturated fat that makes the difference," she said. "It is the saturated fat, those fats that are solid at room temperature, such as butter, lard, bacon and chicken fat, and from the plant world, palm and coconut oil, that we want to limit."

These fats increase the risk for inflammation, and cardiovascular and other chronic diseases, Heller said.

"Try using more oils that are liquid at room temperature, such as extra virgin olive oil, canola, avocado, walnut, sesame or sunflower oils in spreads, sauces and cooking," she suggested.

"Oils can be flavored with vinegars, spices, herbs and add-ins like sun-dried tomatoes," Heller said. "Use nut and seed butters instead of butter on toast, and olive oil on potatoes and vegetables. For recipes that need solid fats, for example in baking, then a plant-based spread or butter is fine to use."