A food science professor has revealed surprising insights into the health differences between butter and margarine, highlighting recent manufacturing changes that have significantly altered the nutritional profile of margarine.
The Great Debate: Butter vs Margarine
Most people think they know which is healthier between butter and margarine. However, recent discussions with food scientists have shed light on changes in margarine production and some concerning health statistics.
Professor Sarah Berry, Professor of Nutritional Sciences at King's College London and Chief Scientist at health and nutrition company ZOE, appeared on a podcast to explain the latest thinking on the differences between the two spreads.
History of Margarine
Margarine was invented in 1869 when Napoleon called for a low-cost alternative to butter to feed his troops. Hippolite Mège-Mouriès created the first margarine using animal fat and milk. In 1902, a German scientist developed hydrogenation, a process that hardens liquid oils like canola or soybean oil into solid fats like margarine.
Prof Berry explained: “It's a chemical process that changes the unsaturated fatty acids in the seed oil to a saturated fatty acid. This changes the chemical structure but increases the melting point, making it a harder fat.”
How Butter is Made
Butter is made by churning milk until fat molecules clump together, forming a solid lump of butter and leaving buttermilk. Prof Berry noted: “Butter is a saturated-rich fat, with about 60-70% saturated fatty acids, unlike margarines which have about 70% unsaturated fatty acids.”
Declining Margarine Consumption
Since the 1990s, margarine consumption has dipped sharply, with butter regaining popularity in the USA. Dr Berry attributed this to “people being concerned about the types of fats in margarine.”
The Trans Fat Issue
Jonathan Wolf, CEO of ZOE, suggested margarine should be considered an ultra-processed food. Prof Berry emphasized that manufacturing has changed dramatically: “We need to look at how manufacturing has changed over the last few decades. There are many misconceptions about trans fats in margarine.”
In 2007, the World Health Organization proposed reducing industrially produced trans fats, which had already been removed from most foods in the UK and US earlier. Dr Berry said: “Fear of trans fats in margarines explains the dip in popularity in the 1990s.”
Health Comparison
Prof Berry noted that older studies on margarine are tainted by outdated production methods. She explained: “Studies 30-40 years ago showed margarines were bad due to trans fats. But moderate butter consumption seems to have a small impact on health. In Finland, where average butter intake was 45 grams per day, rates of heart disease were high, but diet had other unhealthy components.”
For typical UK and US consumption levels, such as spreading on toast, evidence suggests butter is unlikely to have significant long-term adverse effects.
Modern Spreads
Swapping butter for modern unsaturated fat spreads with no trans fats can reduce LDL cholesterol. However, because these spreads are new, long-term research is lacking. Prof Berry often uses olive oil on bread as a proven healthy alternative: “Extra Virgin Olive oil is the healthiest fat or oil. But I prefer butter for its creamy texture. If I had high cholesterol, I would still use butter on toast but avoid it in cooking.”
