An international team of researchers has successfully demonstrated that olive oil and other plant fats are healthier than butter, providing comprehensive scientific evidence by combining a number of dietary intervention studies and previous research, all showing how this choice affects lifestyle and reduces the incidence of serious diseases, according to what was published by New Atlas citing the journal Nature Medicine. Clemens Wittenbecher, the lead researcher at Chalmers University of Technology and the principal investigator of the study, stated: "The results of the research increasingly confirm the health benefits of a diet rich in unsaturated plant fats, such as the Mediterranean diet, and can help to provide targeted dietary advice for those who may benefit most from changing their eating habits."
### High-Quality Oils
The Mediterranean diet is just one aspect of this study. Scientists from Chalmers University of Technology in Sweden, the German Institute of Human Nutrition, and several other colleges have directly linked how high-quality vegetable oils and butter affect blood fat levels, thereby altering the risk of cardiovascular diseases and type 2 diabetes, regardless of other lifestyle choices. The researchers aimed to eliminate the limitations that afflicted individual studies and weakened the connection between "good" fats and good health by using "fat analysis" to pinpoint blood fat profiles derived from a randomized controlled dietary intervention trial. This allowed the researchers to reduce the results to a multi-fat MLS score that could be applied across a range of studies.
The international research team discovered that high-quality vegetable oils had a significant impact on the participants' multi-fat MLS scores, with high scores observed across the board. Low scores, indicating problematic blood fat levels, were noted in groups consuming animal dairy products, such as butter, instead. Guidelines like those issued by the World Health Organization (WHO) and the American Heart Association recommend "moderate" replacement of saturated fatty acids (SFA) with unsaturated plant fatty acids (UFA), due to study limitations and their results, as well as confounding factors.
The researchers noted that "despite data derived from over 56,000 participants in trials and around 3.7 million participants in observational studies, there is significant variability in total fat intake, saturated fatty acid levels, and nutrient sources replacing dietary saturated fatty acids, as well as study durations and limited data from trials on hard endpoints," explaining that "the certainty of evidence supporting WHO recommendations ranges from very low to moderate, leaving dietary fat quality guidelines open to ongoing debate."
Lead study researcher Fabian Ishleman from the German Institute of Human Nutrition in Potsdam-Rehbrücke explained that "the impact on blood fats was summarized using a multi-fat score," clarifying that "high multi-fat MLS scores indicate a healthy level of blood fats, and high intake of unsaturated plant fats combined with low intake of saturated animal fats can achieve positive MLS levels."
Wittenbecher said, "The diet is so complex that it is often difficult to draw conclusive evidence from a single study," noting that "the new study's approach of using fat science to combine strict controlled dietary intervention studies and future cohort studies tracking long-term health can overcome current limitations in nutrition research." Additionally, the use of multi-fat MLS as a key disease indicator helped prove that replacing saturated fats had a significantly greater impact on outcomes compared to other dietary modifications.
Butter contains about 80% fats, but only 65% are unsaturated fatty acids, 28% are monounsaturated fatty acids (MUFA), and some are polyunsaturated fatty acids (PFA); thus, consuming butter and ghee negatively affects blood fat levels. The researchers also found that individuals with higher unsaturated fat ratios had a 32% lower average risk of cardiovascular diseases and a 26% average reduction in the incidence of type 2 diabetes, highlighting the significant role that high-quality vegetable oils play in mitigating disease risks.
The researchers concluded that "lipidomic scores (fat analysis), which reflect lower saturated fatty acid intake and higher intake of unsaturated plant fatty acids, have consistently been associated with reduced rates of type 2 diabetes and cardiovascular diseases in future cohort studies," explaining that "the association of lipidomic scores with diet and disease risk is stronger than alternative established markers, leading to greater estimated cardiovascular metabolic benefits from improving dietary fat quality."
