Plant Oils Should Replace Butter, This Study Confirms

Although it has been widely agreed that olive oil and other plant-based fats are healthier than butter, scientists have now definitively confirmed it by combining multiple diet-intervention studies and previous cohort research, all of which demonstrate how this lifestyle choice affects the risk of serious diseases.

“Our research further solidifies the health benefits of a diet rich in unsaturated plant fats, such as the Mediterranean diet, and could offer tailored dietary recommendations to individuals who would benefit most from modifying their eating habits,” says Clemens Wittenbecher, the lead researcher at Chalmers University of Technology and the study’s senior author.

Broader Study Links Plant Oils and Butter to Blood Fat Levels

However, the Mediterranean diet is only one part of this study. Researchers from Sweden’s Chalmers University of Technology, the German Institute of Human Nutrition, and several other institutions have directly linked the effects of high-quality plant oils and butter on blood fat levels, thereby altering the risk of cardiovascular disease and type 2 diabetes, independent of other lifestyle factors.

The international team aimed to overcome the limitations of individual studies that weakened the connection between ‘good’ fats and health benefits. By employing “lipidomics” to analyze lipid blood profiles from a randomized controlled dietary intervention trial, they distilled their findings into a multilipid score (MLS), which can be applied to various studies.

High-Quality Plant-Based Oils Improve Blood Fat Profiles

They discovered that high-quality plant-based oils significantly improved participants’ MLS, with consistently high scores. In contrast, low scores, indicating problematic blood fat levels, were observed in groups consuming animal-fat dairy, like butter.

Previously, guidelines from organizations such as the World Health Organization (WHO) and the American Heart Association have moderately recommended replacing saturated fatty acids (SFA) with plant-based unsaturated fatty acids (UFA), due to limitations and confounding factors in earlier studies.

“Despite extensive data from over 56,000 trial participants and approximately 3.7 million observational study participants, there is considerable variation in fat intake levels, nutrients, food sources replacing SFAs, study durations, and limited trial data on definitive outcomes,” noted the researchers. “As a result, the certainty of evidence supporting WHO recommendations ranges from very low to moderate, contributing to ongoing debates in dietary fat quality guidance.”

Study Components and Methodology

The comprehensive new study comprised several components. Initially, researchers focused on the University of Reading’s DIVAS trial involving 113 participants over 16 weeks. One group adhered to a diet high in saturated animal fats, while the other followed a diet high in unsaturated plant-based fats. Following the 16 weeks, blood samples underwent lipidomics analysis to assess the prevalence of 45 specific fatty acid molecules.

“We evaluated the effects on blood lipids using a multilipid score (MLS),” explained Fabian Eichelmann, the study’s lead author from the German Institute of Human Nutrition Potsdam-Rehbruecke. “A high MLS indicates a favorable blood fat profile, and consuming high amounts of unsaturated plant fats and low amounts of saturated animal fats can help achieve such positive MLS levels.”

The MLS was subsequently applied to other extensive observational studies, including the German EPIC-Potsdam study (27,548 participants), Harvard’s Nurses’ Health Studies (121,701 women), and the PREDIMED trial (7,447 participants). Each study consistently demonstrated that a high MLS “significantly” reduced the risk of developing cardiometabolic diseases.

“Dietary research is complex, making it challenging to draw definitive conclusions from a single study,” stated Wittenbecher. “Our approach, utilizing lipidomics to integrate intervention trials with rigorously controlled diets and long-term prospective cohort studies, aims to address current limitations in nutrition research.”

Impact of Replacing Saturated Fats

Using MLS as the primary indicator for disease risk, researchers found that replacing saturated fats had a much greater impact on scores than other dietary adjustments. In the EPIC-Potsdam study, weak correlations were noted between MLS and factors like age, BMI, waist circumference, and blood pressure, while stronger associations were seen with triglycerides and total cholesterol. Margarine was found to improve MLS, whereas butter had a detrimental effect. Margarine typically contains about 80% fat, including 65% saturated fatty acids (SFA), 28% monounsaturated fatty acids (MUFA), and some polyunsaturated fatty acids (PFA).

UFA-Inspired Diets Lower Disease Risk

In the same study, applying the statistical analysis developed for the DIVAS trial, researchers found that participants with a high UFA-influenced MLS had a mean 32% lower risk of cardiovascular disease and a mean 26% lower incidence of type 2 diabetes by the end of the testing period.

The NHS study showed similar results, with a mean 28% lower risk of type 2 diabetes and a 24% lower risk in a subset tested over 10 years.

In the PREDIMED cohort, participants who started with a poor MLS experienced a mean 42% reduction in diabetes risk. The Mediterranean diet had little effect on those with healthier lipid scores before dietary intervention.

Although the researchers acknowledged some limitations, such as the European-centric nature of the studies, the findings highlight the significant role quality plant-based oils play in reducing disease risk.

“Lipidomics scores indicating lower SFA intake and higher plant-based UFA intake were consistently linked to reduced incidences of type 2 diabetes (T2D) and cardiovascular disease (CVD) in prospective cohort studies,” the researchers concluded. The associations between lipidomics scores, diet, and disease risk are stronger than those with established surrogate markers, indicating greater estimated cardiometabolic benefits from improved dietary fat quality.

“Our findings support the cardiometabolic benefits of replacing dietary SFAs with plant-based UFAs by integrating data from randomized controlled trials (RCTs) and nutritional cohorts. This suggests that lipidomics-based scores may offer sensitive metrics for health-related metabolic adaptation to changes in dietary fat quality,” they added.

Read the origal article on: New Atlas

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