Butter or Margarine – which is healthier..?
In an open letter to Diabetes Australia, the AMHS have expressed concerns and requested corrections to misleading and inaccurate claims in a DA recent online article titled ‘Which is better, butter or margarine?’.
The letter highlights the article’s:
– Misrepresentation of saturated fats
– Inaccurate assumptions relating to cardiovascular health
– Failure to address nutrient density
– Promotion of ultra-processed foods over whole food natural fat sources
Signed by AMHS ambassadors, directors and members, including Gary Fettke, James Muecke AM, Peter Brukner, and Laureen Lawlor-Smith.
Read the letter in full here:
Australasian Metabolic Health Society
ausmetabolichealthsoc@gmail.com
14 March 2025
Open Letter To Justine Cain and Grant Brinkworth, Diabetes Australia
Subject: Concerns Regarding Inaccuracies in Diabetes Australia’s Butter vs. Margarine Article
Dear Justine Cain and Grant Brinkworth,
We are writing to express concerns regarding information presented in the recent Diabetes Australia website article, ‘What’s Better: Butter or Margarine?’, dated 4th March 2025. The article contains misleading and outdated dietary advice that could negatively impact individuals managing diabetes and metabolic health.
1. Misrepresentation of Saturated Fats
The article suggests that butter should be avoided due to its saturated fat content, citing outdated recommendations linking saturated fat to cardiovascular disease. However, recent meta-analyses, including research published in The American Journal of Clinical Nutrition, have found no significant evidence that saturated fat increases heart disease risk. Instead, emerging evidence indicates that naturally occurring saturated fats from dairy can have neutral or even beneficial effects on cardiovascular health.
2. Inaccurate Claims About Margarine
The article promotes margarine as a healthier alternative, overlooking the fact that many margarine products contain industrially processed vegetable oils, which are highly susceptible to oxidation. These oils can lead to increased inflammation, a critical concern for individuals with diabetes.
The Diet-Heart Hypothesis predicts that replacing animal sources of saturated fat (eg. butter, ghee, lard, beef tallow) with plant-based spreads and oils rich in polyunsaturated fats (eg. canola, sunflower, safflower, corn, cottonseed, soybean, peanut, and vegetable oil) will lower serum LDL levels, and therefore reduce coronary heart disease events and deaths. To date, four randomised controlled clinical trials have tested the substitution of animal sources of saturated fat with plant-based spreads and oils with respect to cardiovascular disease. While each study demonstrated the capacity of plant-based products to lower serum LDL, no cardiovascular benefits were evident:
See the studies below, which demonstrate an increased risk of CVD and death when butter was substituted for polyunsaturated fatty acids (PUFAs):
- The Rose Corn Oil Trial (1965)8 showed an 86% increased of heart attack and a 364% increased risk of death with corn oil supplementation
- The Minnesota Coronary Experiment (1968)7 showed that while plant oils effectively lowered serum LDL, this was associated with a 22% higher risk of death for every 0.78 mmol/L reduction in LDL
- The Sydney Diet Heart Study (1978)9 found a 62% increased risk of death following substitution of saturated fat sources with plant-based products
- The Women’s Health Initiative10 reported a 26% increased risk of cardiovascular complications in 2006 (increasing to 61% in a 2017 follow-up publication) following substitution of saturated fat sources with plant-based products.
3. Failure to Address Nutrient Density
Butter is a rich source of fat-soluble vitamins such as A, D, E, and K2, which play essential roles in immune function, bone health, and cardiovascular support. The article does not acknowledge these benefits, nor does it discuss the potential nutrient deficiencies associated with replacing butter with highly processed spreads.
4. Oversimplified Approach to Dietary Fats
The article oversimplifies the role of fats in a healthy diet by demonising saturated fats while promoting polyunsaturated seed oils. A more balanced approach would recognize that whole-food sources of fats, including those found in dairy, meat, nuts, and olive oil, can all contribute to metabolic health when consumed as part of a whole-food, nutrient-dense diet.
5. Impact on Blood Glucose Regulation
The article does not acknowledge the importance of stable blood glucose regulation when considering fat sources. Butter, being a natural fat, has a neutral impact on insulin levels, whereas certain margarines contain emulsifiers and additives that may influence gut health and glucose metabolism.
Additionally, the focus on butter versus margarine ignores a larger issue—what these fats are typically consumed with. Spreading either butter or margarine on the toast prominently featured in the image and within the article, or other high-carbohydrate foods can lead to blood glucose spikes, particularly for those managing diabetes or insulin resistance. The blood-glucose response of the meal as a whole should be the primary concern rather than focusing solely on the fat source. A more holistic dietary approach would emphasise whole-food fats while limiting refined carbohydrates to support optimal blood glucose control.
Research continues to demonstrate that carbohydrate restriction can be a powerful tool for improving blood glucose stability, reducing insulin resistance, reversing diabetes and supporting long-term metabolic health. Supporting individuals to prioritise lower-carb, nutrient-dense foods over refined grains and highly processed fats is a more effective strategy for diabetes management. Diabetes Australia, is in fact, recognising Therapeutic Carbohydrate Reduction in the Best Practice Guidelines. https://www.diabetesaustralia.com.au/health-professional-guidelines/
6. Ultra-processed Food Promotion
Butter is a dairy product made by churning cream. Conversely, margarine is an ultra-processed food-like product designed to imitate butter. While butter is mainly composed of dairy fat, margarine is typically industrially manufactured from highly refined vegetable oils, often containing several food additives, including emulsifiers and colourings that have been linked to metabolic dysfunction.
Promoting natural, minimally processed butter over industrially manufactured margarine alternatives aligns with the latest scientific understanding of nutrition, in terms of limiting intake of ultra-processed foods and ingredients.
Given these issues, we urge Diabetes Australia to issue a correction to this misleading article, and advocate for evidence-based, whole-food nutrition guidelines that prioritise blood glucose management and metabolic health.
We appreciate your time and consideration and look forward to your response on this matter.
Sincerely,
Dr Peter Brukner Dr James Muecke Dr Gary Fettke Dr Alex Petrushevski Dr Deepa Mahananda Dr Laureen Lawlor-Smith Dr Penny Figtree Claire McDonnell Liu
Directors, Members and Honorary Ambassadors of the Australasian Metabolic Health Society
