A leading food scientist has issued a reassuring message to anyone who has ever enjoyed a pastry, margarine, or plant-based spread, following the publication of a significant new study.
The Common Fat in Your Food
Professor Sarah Berry, chief scientist at the healthy eating app Zoe and an academic at King's College London, explained that a type of fat known as interesterified (IE) fats is commonly found in these everyday food items. Food manufacturers use these modified vegetable oils because they provide stability and a spreadable texture, making them ideal for bakery products and spreads.
For years, these fats have been the subject of concern, particularly on social media, where they have been labelled as 'toxic'. However, Professor Berry's new research, published this week in the American Journal of Clinical Nutrition, offers a compelling counter-argument to these claims.
What the Groundbreaking Study Found
The randomised controlled trial involved 47 healthy adults who consumed diets containing muffins and spreads made with one of two types of IE fats for a period of six weeks. One type was rich in palmitic acid (often from palm oil), and the other was rich in stearic acid (from other vegetable oils). The participants consumed these fats at a level representing 10% of their total energy intake, a realistic amount for a daily diet.
The research team, which included scientists from King's College London and Maastricht University, then measured a wide range of cardiometabolic risk factors. These included blood cholesterol, triglycerides, inflammation markers, insulin sensitivity, liver fat, and vascular function.
The results were clear. Professor Berry stated: "We found that there were no significant differences in blood cholesterol or triglycerides. There were no adverse effects on markers of inflammation, insulin resistance, liver fat, or vascular function." This was true for both the palmitic and stearic acid-rich fats, indicating that at real-life consumption levels, neither has a negative impact on heart health.
A Shift in the 'Processed Food' Narrative
This study provides crucial evidence against the widespread demonisation of all processed foods. Professor Berry highlighted that these IE fats are now widely used by the food industry as a replacement for trans fats and hard animal fats, which are known to be harmful to cardiovascular health.
The key takeaway for consumers is that they do not need to stress about which of these two specific IE fats appears on an ingredient list. This research suggests that the industrially processed fats currently used in many everyday foods are unlikely to pose a threat to heart health, offering a more nuanced perspective on food processing and its effects.
