A new study published in JAMA Internal Medicine has provided compelling evidence on the long-term health impacts of butter and plant-based oils. The research, based on data from over 221,000 adults across three major cohorts, found that higher butter intake was associated with increased risk of total and cancer-related mortality, while higher consumption of plant-based oils was linked to lower total, cancer, and cardiovascular disease (CVD) mortality.

Key Findings

• Butter Intake and Mortality: Individuals with the highest butter consumption had a 15% higher risk of total mortality compared to those with the lowest intake.
• Plant-Based Oils and Longevity: Those with the highest intake of plant-based oils had a 16% lower risk of total mortality, with significant reductions in cancer and cardiovascular-related deaths.
• Specific Oils Matter:
  • Olive oil: 8% lower total mortality risk per 5g/d increase.
  • Soybean oil: 6% lower total mortality risk per 5g/d increase.
  • Canola oil: 15% lower total mortality risk per 5g/d increase.
• Substituting Butter for Plant-Based Oils:
  • Replacing 10g of butter daily with plant-based oils was associated with a 17% reduction in total mortality and 17% lower cancer mortality.

Study Design & Methods

Researchers analyzed data spanning 33 years from the Nurses’ Health Study, Nurses’ Health Study II, and the Health Professionals Follow-up Study. Participants, who were initially free from cancer, CVD, or diabetes, provided dietary data every four years through validated food frequency questionnaires. Mortality outcomes were determined using National Death Index records and medical evaluations.

Why Plant-Based Oils Are Beneficial

Unlike butter, which is high in saturated fats, plant-based oils contain heart-healthy unsaturated fats that offer multiple benefits:

• Lower LDL (bad) cholesterol and improve lipid profiles
• Reduce inflammation, which plays a role in chronic diseases
• Contain antioxidants, like vitamin E, which may lower cancer risk

Public Health Implications

“These findings reinforce current dietary recommendations advocating for the replacement of saturated fats with unsaturated fats from plant-based sources,” said the study’s senior author. “Simple dietary substitutions—such as using olive or canola oil instead of butter—could have profound health benefits over time.”

Conclusion

The study provides strong evidence that reducing butter consumption and increasing plant-based oil intake can lower the risk of premature death. While more research is needed to explore the molecular mechanisms, these results support the ongoing shift towards plant-based fats in dietary guidelines worldwide.

For more details, visit JAMA Internal Medicine or consult the study’s full publication at www.jamainternalmedicine.com.