- A new study examined how dietary fat intake may affect health outcomes and longevity after a nonmetastatic prostate cancer diagnosis.
- The researchers linked higher saturated fat consumption from animal derived sources such as red meat, butter, and full-fat dairy to a greater risk of death from any cause.
- They also linked replacing animal fats with plant-based fats such as olive oil and nuts to a lower mortality risk.
With 5-year relative survival rates
Researchers at the Harvard T.H. Chan School of Public Health examined the relationship between dietary fat intake after a nonmetastatic prostate cancer diagnosis and the risk of death from different causes.
The researchers found that replacing animal and saturated fats with plant-based and unsaturated fats was associated with a significantly lower risk of overall death, which was driven mainly by reduced cardiovascular and non-prostate cancer mortality.
Conversely, men with the highest saturated fat consumption from animal sources such as red meat, butter, and full-fat dairy had a 24% higher overall death rate compared to those with the lowest intake.
Prostate cancer is one of the most common cancers in men in the U.S., and according to the
The researchers behind the new study wanted to learn more about the relationship between dietary fat intake and health outcomes after a nonmetastatic prostate cancer diagnosis. Their study included nearly 5,000 men diagnosed during a 32-year span.
Their mean age at diagnosis was around 70, and the median follow-up was 12.8 years. Every 4 years, the participants reported how often they had eaten different foods during the previous year.
The scientists used this information to estimate their consumption of saturated, monounsaturated, polyunsaturated, and trans fats. Monounsaturated and polyunsaturated fats are
The team classified the fat based on whether it came from animal or plant sources. Some sources of monounsaturated and polyunsaturated fats include olive oil, nuts, and seeds.
The researchers documented deaths from any cause, including deaths from prostate cancer, cardiovascular disease, other cancers, and other causes.
The scientists next assessed whether the amount, type, and source of dietary fat were associated with mortality. They adjusted the analysis for factors such as age, cancer treatment, BMI, and lifestyle behaviors.
During follow-up, 3,040 participants died, including 803 from cardiovascular disease, 499 from cancers other than prostate cancer, and 441 from prostate cancer.
The participants who had the highest saturated fat intake had a 24% greater risk of death from any cause than those with the lowest intake.
The group with the highest saturated fat intake also had a 42% greater risk of dying from cardiovascular disease.
When the researchers examined substituting calories from one type of fat with another, they found that replacing 10% of total daily calories from animal fat with plant-based fat was associated with a 16% lower risk of death from any cause.
They also analyzed replacing saturated fat with monounsaturated fat. They found an association with a 20% lower risk of death from any cause.
Study author Lorelei Mucci, ScD, MPH, professor of epidemiology at the Harvard T.H. Chan School of Public Health, spoke with Medical News Today and said that several biological mechanisms may work together to explain the results.
“It is likely not one individual mechanism but rather this multitude of pathways that work in concert,” Mucci said.
She said these pathways include inflammation, LDL cholesterol, altered metabolism, and the development of atherosclerosis.
Mucci added that the benefits of plant-based fats may extend beyond the fats themselves. She pointed to a
“Fat composition is likely one component, but not the sole factor underlying the benefits of plant-based fats,” Mucci explained.
She also noted that plant-based foods are associated with lower inflammatory biomarkers and better insulin and metabolic measures.
The researchers found no association between any of the dietary fats studied and the risk of dying from prostate cancer.
Overall, the findings support choosing unsaturated fats over saturated fats and underscore the importance of heart health during long-term prostate cancer survivorship.
S. Adam Ramin, MD, board-certified urologist, urologic oncologist, and medical director of Urology Cancer Specialists in Los Angeles, shared his thoughts on the study with MNT.
“This study isn’t necessarily about strict veganism; it’s about a plant-forward hierarchy,” Ramin said. “This means making healthy fats and plants the ‘hero’ of the meal rather than a side dish or garnish.”
Ramin explained that plant-based foods provide fiber and compounds such as lycopene and isoflavones, which may support metabolic health and help regulate inflammation.
He also noted that a fiber-rich diet may support a healthy gut microbiome, which he called the “immune system sentinel.”
This way of eating may also help lower the risk of cardiovascular disease and diabetes, conditions that can affect long-term survival following a nonmetastatic prostate cancer diagnosis.
“In 2026, we’ve discovered that your fork can shape your future health,” Ramin said. “Start making conscious choices at every meal: fill your plate with plants, limit red meat, and choose healthy fats.”
A word of caution
Ramkishen Narayanan, MD, a board-certified urologist, urologic oncologist, and director of the Center for Urologic Health at Providence Saint Joseph Medical Center, told MNT that the findings reinforce existing dietary advice for prostate cancer survivors.
He noted that the large cohort and lengthy follow-up strengthen the research. However, Narayanan emphasized that since the study was observational, it could not establish that dietary fat directly affected mortality.
“I would not consider the findings alone sufficient to recommend a major change in clinical practice,” Narayanan said. Nevertheless, he added that “diet is an important component of cardiovascular health and overall longevity.”