Consuming animal-based proteins does not increase the risk of death and may even provide a modest shield against cancer mortality, according to a new study that challenges common dietary concerns.
The research, published in the journal Applied Physiology, Nutrition, and Metabolism, drew on data from nearly 16,000 U.S. adults aged 19 and older collected through the National Health and Nutrition Examination Survey (NHANES III). Scientists tracked participants’ typical intake of animal and plant proteins and compared it to their risks of dying from heart disease, cancer or any cause over time.
Contrary to some popular beliefs, higher animal protein consumption showed no ties to elevated mortality rates. Instead, the analysis revealed a slight but statistically significant drop in cancer-related deaths among those eating more animal-derived proteins, such as meat, eggs and dairy.
“There’s a lot of confusion around protein — how much to eat, what kind, and what it means for long-term health,” said Stuart Phillips, a professor and chair of kinesiology at McMaster University who supervised the study. “This study adds clarity, which is important for anyone trying to make informed, evidence-based decisions about what they eat.”
To bolster accuracy, researchers applied sophisticated statistical tools, including the National Cancer Institute’s method for estimating usual dietary intake and multivariate Markov Chain Monte Carlo modeling. These approaches helped account for day-to-day variations in eating habits and reduce errors in self-reported data.
“It was imperative that our analysis used the most rigorous, gold standard methods to assess usual intake and mortality risk,” Phillips said. “These methods allowed us to account for fluctuations in daily protein intake and provide a more accurate picture of long-term eating habits.”
Overall, the study found no connections between total protein intake — whether from animals or plants — and risks of all-cause death, cardiovascular disease or cancer. Even when analyzing animal and plant proteins together, the results held steady: Plant proteins appeared to have little effect on cancer mortality, while animal sources suggested a small protective benefit.
As an observational study, the research cannot establish direct cause and effect, but it highlights patterns in a large, diverse population. Lead researcher Yanni Papanikolaou, president of Nutritional Strategies and a master of public health, emphasized its value alongside other evidence.
“When both observational data like this and clinical research are considered, it’s clear both animal and plant protein foods promote health and longevity,” Papanikolaou said.
The study was funded by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff program. The group had no role in designing the study, collecting or analyzing data, or publishing the findings.
