Is Butter a Healthy Food?

The internet is rife with debates and a big discussion over the past few years has been the notion that butter is a healthy fat.  But where is the evidence?

It is true that study results have been conflicting.  However, investigations on the subject often covered very short time periods, compared diets at one point in time or had a low number of participants.  In addition, the research was usually investigating dietary fatty acids, not primary food sources such as butter and oils.  Any of these factors would limit their applicability to public health.  Researchers acknowledged that studies focusing on the foods that people were actually eating and following their study participants for longer periods were necessary to answer the questions surrounding the health effects of foods like butter and plant-based oils.

Recently a long-term US study out of Harvard T.H. Chan School of Public Health, Mass General Brigham, and the Broad Institute delved into the health effects of butter and plant-based oils (safflower, soybean, corn, canola and olive oil). This was a prospective population-based cohort study that used data from three large cohorts of US adults – the Nurses’ Health Study (1990-2023), the Nurses’ Health Study II (1991-2023), and the Health Professionals Follow-up Study (1990-2023).  The research encompassed over 220,000 US adult male and female participants who were free of cancer, cardiovascular disease or neurodegenerative disease. And, most importantly, this analysis followed its participants for more than 30 years. (1)

Every 4 years the participants answered questions about how often they ate certain types of food.   The researchers then calculated their consumption of butter and plant-based oils through baking, frying, sautéing, spreading on bread or other foods and its use in salad dressings and sauces.  Results of this study were published in March 2025 in the journal JAMA Internal Medicine.  The primary outcome of the analysis was the total incidence of early death with death due to cancer and cardiovascular disease being secondary outcomes.  The National Death Index along with other sources identified participant deaths and a physician classified the cause of death from medical records and death certificates.  Death rates across different diet intakes of butter and plant-based oils were then compared.

Results of this study are as follows;

• After 33 years of follow-up, 50,932 participants had died, 12,241 from cancer and 11,240 from cardiovascular disease.
• Overall, higher butter intake was associated with increased early death from any cause and increased early death from cancer. In contrast, higher intake of plant-based oils was associated with decreased early death from any cause, cancer and cardiovascular disease.
• Participants who ate the most butter had a 15% higher risk of early death from any cause compared to those who ate the least butter.
• Participants who ate the most plant-based oils had a 16% lower risk of early death from any cause compared to those who ate the least plant-based oils.
• For every 5 gram per day increase in consumption of plant-based oils, the risk of early death from any cause decreased by 15% for canola oil, 8% for olive oil, and 6% for soybean oil. In contrast, corn oil showed no significant association between higher intake and reduced early death.
• Every 10 gram increase in plant-based oil intake was associated with an 11% lower risk of early death from cancer and a 6% lower risk of early death from cardiovascular disease while a higher intake of butter was associated with a 12% higher risk of early death from cancer.
• Substituting 10 grams of butter (about 2 teaspoonsful) with an equivalent amount of plant-based oils was associated with a 17% reduction in both early death from any cause and early death from cancer.

The researchers of this study are planning future studies looking into the mechanisms underlying these powerful impacts on health, but they point out that they may be due to their content of fatty acids.  Butter is rich in saturated fatty acids (SFAs) while plant-based oils contain more unsaturated fatty acids.  Multiple studies have shown that intake of SFAs is linked to increased risk of cardiovascular disease while reduced intake of SFAs, especially when replaced with poly-unsaturated fatty acids or carbohydrates from whole grains, is linked to a reduction in the risk of coronary heart disease and early death.  (2,3,4)

The researchers concluded that replacing butter with plant-based oils, particularly canola oil, olive oil and soybean oil, may have substantial benefits for health and the prevention of premature death.  Even cutting back on butter by a small amount and increasing the use of plant-based oils has the potential for health advantages.  This one simple switch, from butter to plant-based oils, could be the first step along a path toward a longer, healthier life.

 

 SOURCES:

1  Zhang, Y., Chadaideh, K.S., Li, Y., et al. Butter and Plant-Based Oils Intake and Mortality. JAMA Intern Med. Published online March 06, 2025. Doi:10.1001/jamainternmed.2025.0205

2  Krauss, R.M., Kris-Etherton, P.M. Public health guidelines should recommend reducing saturated fat consumption as much as possible: debate consensus. Am J Clin Nutr 2020;112:25–26.

3  Oteng, A.B., Kersten, S. Mechanisms of action of trans fatty acids. Adv Nutr 2020;11:697–708.

4  Kris-Etherton, P.M., Krauss, R.M.. Public health guidelines should recommend reducing saturated fat consumption as much as possible: YES. Am J Clin Nutr 2020;112:13–18.