Share on PinterestScientists have compared the use of butter and plant-based oils in terms of death and cancer risk. Design by MNT; Photography by SimpleImages/Getty Images & Elena Noviello/Getty Images
- A new study suggests that swapping butter for plant-based oils, particularly olive oil, soybean oil, and canola oil, may reduce the risk of premature death.
- Researchers observed that substituting 10 grams of butter a day with an equal amount of plant-based oil was associated with an estimated 17% reduction in overall mortality and a 17% reduction in cancer mortality.
- Experts say that prioritizing healthy fats, particularly those with higher amounts of omega-3 fatty acids, is important for overall health.
Swapping butter for plant-based oils, in particular olive oil, soybean oil, and canola oil, may contribute to a reduced risk of premature death, according to a new study.
The cohort study, published this week in JAMA Internal Medicine, examined data drawn from more than 200,000 people among three different populations: the Nurses’ Health Study (1990-2023), the Nurses’ Health Study II (1991-2023), and the Health Professionals Follow-up Study (1990-2023). Included in each study were participants who were free of cancer, cardiovascular disease, diabetes, or neurodegenerative disease.
Butter intake was considered through cooking with butter or adding butter to food during meals, and plant-based oil alternatives were olive oil, soybean oil, corn oil, canola oil, and safflower oil. During up to 33 years of follow-up, participants were given food intake questionnaires at baseline and every four years.
Researchers observed that substituting 10 grams of butter a day with an equal amount of plant-based oil was associated with an estimated 17% reduction in overall mortality and a 17% reduction in cancer mortality.
Not all fats are created equal
Cheng-Han Chen, MD, board certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, who was not involved in the study, told Medical News Today that butter’s contribution to low-density lipoprotein (LDL) — known as “bad” cholesterol — makes it stand out compared to other dairy products.
“Butter is high in saturated fat and calories, making it a less healthy option than other dairy products like milk, cheese, or yogurt,” Chen said. “It is this saturated fat that increases someone’s risk of developing heart disease, particularly through increasing ‘bad’ cholesterol levels.”
David Cutler, MD, board certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA, who was also not involved in the study, told MNT that not all fats are created equal — some are beneficial to overall health.
“It’s important to remember that it is essential to have some fat or oil (liquid fat) in our diets. We ingest these substances as fatty acids and then transport them in our blood stream as triglycerides,” Cutler said.
“Fatty acids are necessary components of many cells in our bodies, circulating chemicals and important hormones. There are also certain fat-soluble vitamins (A, D, E, and K) which require fats in our diets to be absorbed. While our bodies can manufacture many of the fatty acids necessary for survival, there are two ‘essential’ fatty acids which we cannot manufacture and must be included in our diets,” he explained.
What are good sources of healthy fats?
Choosing fats in their most unprocessed form — and prioritizing those with benefits to metabolism and long-term health — is the most important aspect to consider when thinking about good sources, Melanie Murphy Richter, MS, RDN, a nutritionist and founder of Wholistic Ritual, who also was not involved with the study, told MNT.
“From a functional nutrition standpoint, fats are not just a source of energy but essential for cellular repair, hormone production, brain function, and inflammation regulation. Whole-food sources of fat offer the greatest benefits because they come with additional nutrients that support the body’s ability to process and utilize fats efficiently,” Richter said.
Richter provided a list of sources for good fats, including:
- Nuts and seeds – Almonds, walnuts, flax, chia, and hemp seeds provide omega-3s, fiber, and plant-based protein, which help balance blood sugar, reduce inflammation, and support gut health.
- Avocados – A rich source of monounsaturated fats, potassium, and fiber that supports heart health, insulin sensitivity, and satiety.
- Cold-pressed extra virgin olive oil – High in polyphenols and monounsaturated fats, olive oil is known for its ability to combat oxidative stress and support vascular health.
- Fatty fish – Wild salmon, sardines, and mackerel provide long-chain omega-3s (EPA and DHA), which are critical for brain function, reducing inflammation, and maintaining metabolic health.
- Grass-fed butter and ghee – These contain fat-soluble vitamins A, D, E, and K2, along with butyrate, which supports gut health.
- Coconut and MCT oil – These oils contain medium-chain triglycerides (MCTs), which are rapidly converted into energy rather than stored as fat, making them beneficial for brain function and metabolic support when used in moderation.
Omega-3 fatty acids should also be part of the calculus when picking butter substitutes or healthy sources of fat. Cutler explained that omega-3 fatty acids, which include the essential alpha linolenic acid, can help lower LDL (bad) cholesterol, therefore, cardiovascular risk.
“Vegetable oils which are high in omega-3 fatty acids are flaxseed and walnut oil. Fish oil is another source of omega-3 fatty acids which tend to lower the risk of cardiovascular disease,” Cutler said.
“Omega-6 fatty acids, like the essential linoleic acid, are prevalent in corn and soybean oil, and these have limited conversion to EPA and DHA.” So, while research on the effects of these oils on heart health remains mixed, Cutler suggests they do not lower LDL cholesterol or reduce cardiovascular risk.
Should you avoid butter?
Grass-fed butter, which comes from cows that eat primarily grass, is seen as a much healthier version of butter. It contains more nutrients, such as the natural fatty acid conjugated linoleic acid (CLA), which has been noted for its potential positive effects on cancer, cardiovascular disease, chronic inflammation, and immune function. But, as with most aspects of dietary health, balance is key.
“A small amount of butter consumed in moderation can still be part of a well-balanced diet,” Dr. Chen said. “Grass-fed butter (butter from grass-fed cows) is thought to be a healthier option than regular butter, as it contains lower levels of saturated fat and higher levels of unsaturated fat and Vitamin A.”
Richter agreed, pointing to how butter’s effects on health depend on someone’s overall diet and their metabolic response, but noting that grass-fed is preferable.
Grass-fed vs. regular butter
“Grass-fed butter has a significantly different nutrient profile than conventional butter, providing higher levels of omega-3s, conjugated linoleic acid (CLA), and vitamin K2, which support heart health, immune function, and metabolic balance. It also contains butyrate, a short-chain fatty acid that supports gut barrier integrity and inflammation regulation. Conventional butter, typically from grain-fed cows, is lower in these nourishing nutrients and is also higher in omega-6 fatty acids, which can contribute to inflammation.”
— Melanie Murphy Richter, MS, RDN
