Plant vs. animal protein: New study challenges longstanding health concerns over meat

A new meat industry-funded study advocating for animal-sourced protein consumption claims this food group is not linked to a higher risk of death and may even offer protective benefits against cancer-linked mortality.

The results contrast a growing body of evidence demonstrating the positive health impacts of a diet that is largely plant-based and lower in meat and dairy.

Published in Applied Physiology, Nutrition, and MetabolismI, the study analyzed data from nearly 16,000 adults aged 19 and older using the National Health and Nutrition Examination Survey (NHANES III).

The researchers examined the relationship between the amount of animal and plant protein people ate and their risk of dying from major diseases.

The findings suggest that consuming more animal protein did not increase the risk of death from heart disease, cancer, or any other cause. The study also showed a “modest but significant reduction” in cancer deaths among those with a higher intake of animal protein.

“There’s a lot of confusion around protein — how much to eat, what kind, and what it means for long-term health. This study adds clarity, which is important for anyone trying to make informed, evidence-based decisions about what they eat,” says research supervisor Stuart Phillips, professor and chair of the Department of Kinesiology at McMaster University, Canada.

Animal protein and morbidity risk

The researchers reportedly found no links between the consumption rate of animal protein or plant protein and the risk of death from any cause, including cardiovascular disease or cancer.

Diets rich in plants and low in meat are strongly backed by research to support many areas of health.The analysis included plant and animal protein, and the results remained consistent. The study concludes that plant protein has a “minimal impact” on cancer mortality, while animal protein may offer a “small protective effect.”

To investigate these effects, the researchers used advanced statistical methods, including the National Cancer Institute (NCI) method and multivariate Markov Chain Monte Carlo (MCMC) modelling, to estimate long-term dietary intake and minimize measurement error.

“It was imperative that our analysis used the most rigorous, gold standard methods to assess usual intake and mortality risk. These methods allowed us to account for fluctuations in daily protein intake and provide a more accurate picture of long-term eating habits,” says Phillips.

McMaster University concedes that observational studies like this one can’t prove cause and effect. However, the team stresses they are valuable for identifying patterns and associations in large populations.

“When both observational data like this and clinical research are considered, it’s clear both animal and plant protein foods promote health and longevity,” argues lead researcher Yanni Papanikolaou, MPH, president, Nutritional Strategies.

This study was funded by the National Cattlemen’s Beef Association (NCBA), a contractor to the Beef Checkoff. McMaster University maintains that NCBA was not involved in the study design, data collection and analysis, or publication of the findings.

Plants power forward

The paper’s findings contrast mounting evidence that diets embracing a diversity of plants — not just focusing on quantity — may provide an overall health boost against the risk of multimorbidities.

One recent UK report found that a plant-based diet is linked to better heart and metabolic health, while other previous analyses support its benefits in weight loss, postmenopausal hot flashes, and inflammatory bowel disease.

Consuming more plants also supports a healthier and more diverse gut microbiome, according to another scientific analysis of 21,561 people. Gut health is increasingly linked to various holistic health claims, such as mental wellness and cardiometabolic performance.

Diets high in animal protein also often come with the health risk of raising saturated fat levels. MIT and Harvard researchers cautioned against high animal fat consumption, finding that people who replace butter with plant-based oils may have a lower risk of premature death.