Humans have been eating butter for millennia, valuing its ability to store longer than most meat and its utility as a flavoring. In the early 1900s, U.S. butter consumption averaged more than 18 pounds a person per year.
A French chemist invented margarine in 1869 in response to Napoleon III’s call for a butter alternative. Initially it used fat from slaughtered animals that was cheaper than milk used for butter. Modern varieties using plant oils arose in the first half of the 20th century, when brands like Blue Bonnet and Parkay flourished. It gained more popularity around World War II, when butter was rationed.
Food producers liked margarine’s lower cost. Health experts further fueled its rise by raising concerns about butter’s cholesterol and saturated fats linked to heart disease. By its peak in 1976, U.S. margarine consumption reached 11.9 pounds a person, according to USDA data.
As butter consumption fell to a nadir of 4.1 pounds per capita in 1997, scientists increasingly were emphasizing that trans fats could pose greater risks than other fats for heart disease.Technically, both butter and margarine contain at least 80% fat. Butter alternatives made from vegetable-based oils, such as products from Smart Balance, are often referred to as “spreads” and tend to contain less fat. Typical margarine components, like soybean and corn oils, tend to be liquid at room temperature. To solidify them, manufacturers change their chemical structures using hydrogen. Partial hydrogenation can also produce trans fats, which have been shown to increase levels of harmful cholesterol in humans.
“The battle has been back and forth,” said professor and food scientist Sean O’Keefe at Virginia Polytechnic Institute and State University. “In the 60s and 70s, before trans fats were really thought to be bad, we looked at margarine and said it was healthier because it didn’t have as much saturated fat. The opposite is the case today.”
via Butter Makes Comeback as Margarine Loses Favor – WSJ.