A recent large-scale study has found that eating protein—whether it comes from plants or animals—does not raise the risk of dying early. Surprisingly, the research also suggests that animal protein may be linked to a slightly reduced risk of cancer-related deaths.
These findings offer a new perspective in a long-standing debate over the health effects of animal-based protein. While earlier studies raised concerns about meat, dairy, and eggs contributing to chronic diseases, this analysis indicates that moderate protein consumption from any source is not harmful to longevity.
Study Design and Approach
The study drew data from the Third National Health and Nutrition Examination Survey (NHANES III), which tracked the health and diet of over 15,000 American adults aged 19 and older. Participants were followed over a 12-year period, during which researchers monitored deaths caused by cancer, cardiovascular disease, and other factors.
To improve the accuracy of dietary assessments, researchers used a statistical technique known as Markov Chain Monte Carlo (MCMC) modeling. This approach allowed them to estimate typical protein intake, correcting for daily fluctuations and reporting errors common in food surveys.
The analysis distinguished between animal-based proteins (such as meat, dairy, and eggs) and plant-based proteins (like beans, nuts, and grains). Researchers also factored in blood levels of insulin-like growth factor 1 (IGF-1), a hormone that has been linked to cancer development in previous studies.
Lifestyle variables such as age, gender, smoking, physical activity, and total caloric intake were also adjusted to better isolate the effects of protein consumption.
Key Results: No Elevated Risk, Possible Protective Effect
The findings revealed no increased risk of early death among those who consumed higher levels of either animal or plant protein. In fact, participants with greater animal protein intake showed a slightly lower chance of dying from cancer.
Incorporating IGF-1 levels into the analysis did not change the outcome—there was no significant connection between this hormone and mortality risk.
The study’s results remained consistent across age groups, including adults under 65, those between 50 and 65, and seniors over 65. This is particularly noteworthy because prior research suggested that protein intake may pose a higher risk for people in middle age. However, this study found no such age-related differences.
Researchers noted that differences in data collection and analysis techniques likely explain the contrast with older studies. By using more advanced statistical models and ensuring well-distributed participant groups, this research presents a more reliable picture of long-term protein intake and health outcomes.
Implications for Protein Recommendations
According to Avery Zenker, a health writer with MyHealthTeam who was not involved in the study, the results support existing dietary guidelines.
“This study shows that consuming more than the minimum daily protein recommendation—0.8 grams per kilogram of body weight—doesn’t appear to shorten lifespan,” Zenker told Healthline.
She emphasized that protein intake should be tailored to individual needs, typically falling within 10–35% of total daily calories, based on factors like age, activity level, muscle maintenance, and satiety.
Zenker did caution that not all protein sources are created equal. “Previous studies have linked high consumption of processed meats to increased risk of heart disease and certain cancers,” she noted.
While the study adds valuable insight, Zenker reminded readers that observational research can’t establish causation and that dietary patterns should be viewed in a broader health context.
“Protein foods also provide other nutrients—like fiber, fat, vitamins, and minerals—that affect overall health,” she said.
Individual Protein Needs Vary
Maura Donovan, a board-certified sports dietitian and Medical Education Specialist at Thorne (who was also not involved in the research), stressed that protein requirements vary from person to person.
“Older adults often need more protein to help maintain muscle mass and strength as they age,” she said.
Donovan explained that athletes and active individuals also require more protein to support muscle recovery, and that people recovering from illness or injury benefit from increased protein intake to assist immune function and healing.
For vegetarians and vegans, she recommended combining different plant protein sources to ensure a complete intake of essential amino acids.
She encouraged anyone with specific dietary needs to consult a registered dietitian. The Academy of Nutrition and Dietetics offers a searchable directory to help individuals connect with qualified professionals.
Conclusion:
This study offers reassurance that moderate protein intake—from both animal and plant sources—does not increase the risk of early death. In fact, it may offer some protective benefits, particularly against cancer. While individual protein needs differ, most people can feel confident including protein as part of a balanced, health-conscious diet.
