For millions of people, enjoying butter on toast or a slice of cheese may not be the health risk it was once thought to be, according to significant new research. A comprehensive scientific review indicates that for individuals not already at high risk of heart problems, reducing intake of saturated fats has little impact on mortality.
Shifting Perceptions on Dietary Fats
The long-standing reputation of saturated fats as dietary villains, linked to clogged arteries and increased risk of heart attacks and strokes, is being challenged. The research, published in the Annals of Internal Medicine on Tuesday 16 December 2025, analysed data from 17 separate studies involving 66,337 participants.
It concluded that the benefits of cutting back are largely confined to a specific group. "For persons at low cardiovascular risk, reducing or modifying saturated fat intake has little or no benefit over a period of 5 years," the research team stated. However, they found important reductions in mortality and major cardiovascular events for those already at high risk.
Experts Suggest a More Nuanced View
In an editorial accompanying the study, Dr Ramon Estruch and Dr Rosa Lamuela-Raventós from the University of Barcelona signalled a profound shift in scientific thinking. They quoted Bob Dylan, writing "The Times They Are A-Changin'" in reference to the debate on saturated fatty acids (SFAs).
They argued that the perception has moved from strictly negative to recognising possible protective effects for some subtypes of SFAs. The scientists criticised the traditional 'diet-heart hypothesis', which blames saturated fats for raising cholesterol and causing heart disease, as being "based on weak evidence of association and not causation".
Instead, they propose that certain saturated fats, when consumed as part of a diet rich in healthy unsaturated fats, may offer benefits. "Maintaining a high intake of polyunsaturated and monounsaturated fatty acids, along with the consumption of short-, medium-, and very long-chain SFAs... may confer salutary benefits within the context of an overall healthy and balanced diet," they concluded.
Calls for Caution and Context
Despite the findings, some experts urge the public not to abandon current guidance prematurely. Professor Nita Forouhi, a population health and nutrition expert at the University of Cambridge, noted the analysis did not examine health outcomes beyond five years. "For this reason, it would be premature to change existing dietary guidelines," she told the Mail.
Current NHS advice remains that too much saturated fat can raise cholesterol and increase heart disease risk. It recommends men eat no more than 30g per day and women no more than 20g, advocating replacing saturated fat with unsaturated fats where possible.
This major meta-analysis adds a crucial layer of nuance to the public health conversation, suggesting that blanket warnings may be less useful than personalised dietary advice based on an individual's existing health risks.
