A new analysis has found no evidence that consuming higher amounts of protein—whether from animal or plant sources—increases the risk of early death. In fact, animal protein may even offer a slight protective effect against cancer-related deaths.

While earlier research has suggested potential health risks associated with eating large amounts of meat, eggs, or dairy, this new study challenges those claims, finding no harmful effects from moderate to high protein consumption. Experts say current dietary recommendations remain valid, though individual needs may vary.

Research Overview

Published in Applied Physiology, Nutrition, and Metabolism on July 16, the study examined data from the Third National Health and Nutrition Examination Survey (NHANES III), which tracked more than 15,000 adults in the U.S. from 1988 to 1994. All participants were at least 19 years old and were followed for a 12-year period to assess death rates from various causes, including cancer and cardiovascular disease.

To address the difficulty of accurately measuring food intake, researchers used a sophisticated statistical method called the multivariate Markov Chain Monte Carlo (MCMC) model. This approach allowed them to estimate participants’ usual protein intake, accounting for day-to-day dietary changes and common self-reporting errors.

The study also included analysis of blood levels of insulin-like growth factor 1 (IGF-1), a hormone that previous studies have linked to increased cancer risk and overall mortality.

Researchers separated protein into two main categories—animal-based (meat, eggs, dairy) and plant-based (legumes, grains, nuts)—to examine whether different protein sources influenced health outcomes differently.

Main Findings

The results showed no connection between higher protein intake—regardless of source—and a greater risk of early death. This was consistent for all causes of death, including cancer and heart disease.

Surprisingly, those who consumed more animal protein actually showed a slightly lower risk of dying from cancer. Including IGF-1 data in the analysis didn’t alter the findings, suggesting that the hormone might not play as strong a role in mortality as once thought.

Additionally, the study found that the lack of risk associated with protein intake held true across all age groups. Whether participants were under 65, between 50 and 65, or over 65, protein consumption was not linked to earlier death. This goes against previous studies that suggested middle-aged adults might be more vulnerable to high-protein diets.

Researchers believe their more accurate methods and better data may explain why these results differ from earlier findings.

Expert Opinions

Health experts agree that this study supports current protein intake guidelines. Avery Zenker, a health and medical writer not involved in the study, said that the findings confirm it’s safe to consume more than the minimum recommended amount of protein.

“The study showed that going above 0.8 grams of protein per kilogram of body weight didn’t negatively impact lifespan,” Zenker told Healthline. She emphasized that protein intake should still be tailored to individual health goals—whether that’s maintaining muscle, promoting fullness, or supporting recovery.

However, Zenker also warned that not all protein-rich foods are equal. “Previous research still links processed meats to increased risks of cancer and heart disease,” she said. “And while this study offers reassurance, it doesn’t mean everyone should increase protein without considering quality and balance.”

She also reminded readers that foods with protein contain many other nutrients—like fiber, fat, vitamins, and minerals—which can influence health outcomes.

Personalized Protein Needs

Maura Donovan, a board-certified sports dietitian and medical educator at Thorne (who also was not involved in the study), said protein needs vary by individual.

“Older adults need more protein to preserve muscle and stay functional,” Donovan said. “Athletes require additional protein to help with muscle recovery, and those healing from injuries or illness benefit from increased intake as well.”

She added that vegetarians and vegans should combine a variety of plant-based protein sources to ensure they receive all essential amino acids.

Donovan recommends consulting with a registered dietitian to determine the right amount of protein for your lifestyle and health goals. The Academy of Nutrition and Dietetics provides an online directory of certified professionals.

Final Thoughts

This large-scale, nationally representative study offers important insights: typical levels of protein intake from either plants or animals are not linked to early death. In fact, moderate animal protein consumption may offer some health protection, especially against cancer.

While protein quality and overall diet remain important, this study suggests there’s no need to fear protein intake when it comes to long-term health or lifespan.