A recent study suggests that choosing plant-based oils over animal fats may have significant health benefits. Researchers found that incorporating oils like olive and canola into one’s diet could help reduce the risk of serious health issues, including heart disease, cancer, and early death. The findings support dietary guidelines that recommend replacing saturated fats, such as butter, with unsaturated fats from plant sources.
Key Highlights:
- Daily consumption of a tablespoon of butter — when used as a spread, not for cooking — was linked to a 15% increase in the risk of dying prematurely compared to those who consumed the least amount of butter.
- Individuals who frequently included plant-based oils like olive or canola oil in their diet experienced a lower risk of early death than those who rarely used these oils.
- Replacing butter with plant oils was associated with improved longevity and a reduced risk of premature death.
If you’re among those who believe that everything tastes better with butter, you might want to take a closer look at your dietary choices. A new study published in JAMA Internal Medicine offers compelling evidence that butter lovers may face a heightened risk of dying early. In contrast, individuals who favor plant-based oils such as olive, canola, and soybean oils seem to enjoy a significantly lower risk of premature death. The findings contribute to a growing body of research suggesting that not all fats are created equal—and that the source of dietary fat plays a pivotal role in long-term health outcomes.
Study Overview and Demographics
The research involved approximately 221,000 adults, most of whom were in their mid-fifties at the start of the study. Importantly, none of the participants had been previously diagnosed with major health conditions like heart disease, diabetes, cancer, or neurodegenerative diseases such as Alzheimer’s or multiple sclerosis. Over the course of more than three decades, these individuals completed detailed dietary questionnaires every four years, reporting on their intake of various fats, including butter and oils like safflower, soybean, corn, canola, and olive.
By the end of the study period, 50,932 participants had died. Of these, 12,241 deaths were attributed to cancer and 11,240 to heart disease. Researchers analyzed the data while controlling for key variables such as age, BMI, physical activity levels, smoking and alcohol use, and pre-existing conditions like high blood pressure or high cholesterol.
Butter Consumption Linked to Higher Mortality
One of the study’s most concerning findings was the link between butter consumption and premature death. Participants who consumed the most butter—approximately 13 to 14 grams per day, or about one tablespoon—had a 15% higher risk of dying from any cause compared to those who consumed the least, at around 0.2 grams daily. Interestingly, the study found that the elevated risk was associated with butter used as a spread rather than in cooking or baking.
These findings underscore that even small, consistent amounts of saturated fat may negatively impact health over time. “The fat in butter is mostly saturated fat, which is considered unhealthy because it increases bad cholesterol in the blood, which is linked to a higher risk of heart disease,” explained Yikyung Park, ScD, professor at the Washington University School of Medicine in St. Louis, who was not involved in the research.
The Benefits of Plant-Based Oils
In sharp contrast to butter, the study found that plant-based oils were linked to a reduced risk of early death. Participants who consumed the highest quantities of plant oils—around five teaspoons daily—were 16% less likely to die prematurely compared to those who consumed the least, at about one teaspoon per day.
Three oils in particular stood out: canola, soybean, and olive oil. These oils, rich in unsaturated fats, were most strongly associated with longevity benefits. Each additional 10 grams per day of these oils was linked to an 11% decrease in cancer-related deaths and a 6% reduction in deaths from heart disease. Meanwhile, each extra 10 grams of butter was associated with a 12% increase in cancer-related deaths, though it didn’t significantly alter heart disease mortality.
Dr. Park emphasized the biological mechanisms that may explain this disparity. “Unsaturated fats can improve your blood lipid profile and help fight inflammation in the body,” she said. Research has shown that unsaturated fats—both polyunsaturated and monounsaturated—can help reduce LDL or “bad” cholesterol, which plays a central role in the development of heart disease.
Practical Implications for Your Diet
While the study offers strong associations between fat type and longevity, it doesn’t definitively prove causation. One limitation was the reliance on self-reported data, which can be affected by memory lapses or misreporting. Moreover, most of the participants were white healthcare professionals, which may limit the generalizability of the findings to more diverse populations.
Still, the broader implications are clear: making better fat choices is likely part of an overall healthier lifestyle. “The lower mortality with plant-based oils is most likely related to people using these as part of a healthier diet,” said Penny M. Kris-Etherton, PhD, RD, emeritus professor of nutritional sciences at Pennsylvania State University. “They would have a higher diet quality, which decreases the risk of cardiovascular disease and cancer.”
Dr. Kris-Etherton highlighted that the context in which plant oils are consumed also matters. “Using these oils to prepare vegetables, lean proteins like poultry or seafood, or in homemade salad dressings is where the real benefits are,” she said. “But if you’re eating ultra-processed foods that just happen to contain plant oils, you’re unlikely to see the same health advantages.”
Moderation and Balance Still Matter
Despite the clear benefits of plant-based oils, experts warn that moderation remains important. “While plant-based oils are a healthier choice than butter, eating too much of any oil can increase your calorie intake and potentially lead to weight gain,” Dr. Park noted. Current dietary guidelines recommend that fats—regardless of type—should comprise no more than 20 to 35% of your daily calories.
This means thoughtful use of oils, such as drizzling a moderate amount over roasted vegetables or using a measured quantity in salad dressing, rather than pouring them freely. It also means paying attention to total fat intake from all sources throughout the day.
A Growing Consensus on Healthy Fats
The findings from this long-term study contribute to the growing scientific consensus that unsaturated fats are superior to saturated fats when it comes to promoting long-term health. Nutritionists and public health organizations have been advising similar dietary swaps for years, and now the data continues to reinforce these recommendations.
If you’re looking to adopt healthier eating habits, a good first step might be as simple as switching from butter to olive oil when making your morning toast or sautéing your vegetables. Over time, these small shifts can lead to substantial improvements in health outcomes—and possibly even extend your life.
As Dr. Kris-Etherton concluded, “Nutrition is not about single foods but about overall patterns. When healthier choices like plant-based oils become the norm in a person’s daily routine, the benefits really start to add up.”