Protein and Longevity: The Role of Dietary Choices in Health and Lifespan Summary

  • Researchers examined the relationship between protein and longevity in 833 older adults.
  • The study found that those with the highest protein intake had a 56% reduced risk of all-cause mortality compared to those with a low protein intake.
  • A high protein diet is associated with a reduced risk of all-cause mortality in older adults (aged ≥ 85 years) who engage in independent activities of daily living. The association may impact mortality independent of muscle mass.


Diet plays a pivotal role in determining our overall health and longevity. Among the macronutrients, protein is a vital component for muscle growth, repair, and overall body function. Emerging evidence suggests that the balance of macronutrients and the specific role of protein in the diet may have a more significant impact on longevity and metabolic health than total calorie intake. (Kitada et al., 2019) Historically, the relationship between protein consumption and lifespan has been debated, especially at different life stages. (Naghshi et al., 2020) Some have suggested that protein restriction is beneficial whereas others have suggested that older adults have higher protein requirements.

Animal Protein and Longevity

high protein and longevity protein and longevity animal protein and longevityIn Europe and the U.S., higher animal protein intake has been linked to an increased risk of death from cardiovascular disease.(Song 2016) Conversely, higher plant protein intake seems to offer protective benefits. (Yu et al., 2023) However, a higher protein intake correlates with a reduced mortality risk in regions like China, highlighting the importance of a balanced and healthy life. (Chan et al., 2019) These varying findings highlight the complexities of diet and its impact on health. Regional differences in eating habits may influence these findings. For instance, while the U.S. consumes more fat, Japan consumes more protein and carbohydrates. The source of animal protein also varies, with Western countries consuming more red and processed meat, while Japan consumes more fish and shellfish.

A recent study titled “Dietary protein intake and all-cause mortality: results from The Kawasaki Aging and Wellbeing Project” has shed light on the intriguing relationship between protein intake and mortality, especially in older adults. Let’s dive into the findings and what they mean for our dietary choices.

Background on Protein and Longevity

Proteins are complex molecules that are crucial in nearly every bodily process. They are made of amino acids and can be found in various foods. While animal sources like meat, poultry, and fish are rich in protein, plant sources like beans, lentils, and nuts also offer significant amounts. The recommended daily intake of protein varies, but for an average adult, it’s essential to ensure a balanced intake for optimal health.

Historical Perspective on Protein and Longevity

high protein and longevity protein and longevity animal protein and longevityInterestingly, the source of protein and longevity also plays a role in its health implications. For instance, in Western countries, a significant portion of animal protein comes from red meat and processed meat (Yu et al., 2023), which is associated with increased mortality risks. (Schwingshackl et al., 2017) In contrast, in Japan, the primary source of animal protein is fish and shellfish (Budhathoki et al., 2019), known for their health benefits. Fish, in particular, is rich in n-3 unsaturated fatty acids, vitamins, essential amino acids, and trace elements, contributing to its positive impact on health.(Pedersen et al., 2013)

The role of protein intake in maintaining muscle mass and function is also essential for healthy aging and longevity. Age-related muscle loss, known as sarcopenia, is a common condition in older adults and is associated with increased frailty and mortality. (Beasley et al., 2013) Adequate protein intake and exercise are crucial for preserving muscle mass and function in older adults. (Deutz et al., 2014) This highlights the importance of protein intake in maintaining overall health and longevity.

Details of the Recent Study on Protein and Longevity

A team of researchers, led by Hideaki Kurata, embarked on a mission to understand the relationship between protein and longevity in older Japanese individuals. The study, titled “Dietary protein intake and all-cause mortality: results from The Kawasaki Aging and Wellbeing Project,” focused on 833 older adults (ages 85–89; average BMI of 23; 51% women, 49% men) residing in Kawasaki, Japan, with no apparent health conditions or limitations in performing activities of daily living. The participants were grouped based on their protein intake, and their health outcomes were observed over an average of 1,218 days, with a focus on overall mortality.

The participants filled out a brief dietary history questionnaire on their own. Based on their protein consumption as a percentage of their total energy intake, they were categorized into four groups: those with low intake (below 14.7%), low-to-moderate intake (ranging from 14.7% to 16.7%), moderate-to-high intake (from 16.7% to 19.1%), and those with high intake (19.1% and above).

The study team further assessed the impact of different protein types (such as animal and plant proteins), specific sources of protein (like fish, eggs, dairy, and meat), and the consumption levels of omega-3 fatty acids on the results.


high protein and longevity protein and longevity animal protein and longevityThe results were enlightening. The average protein intake was 17.0% of total energy. Animal protein intake, especially fish, increased with total protein intake. The study found that those with the highest daily protein intake had a 56% reduced risk of all-cause mortality compared to those with the lowest intake. Notably, fish emerged as a significant source of protein for the participants, suggesting its potential benefits in promoting longevity.(Kurata et al., 2023)

These participants also had a higher intake of fats, including omega-3 fatty acids. A deeper analysis revealed that individuals with a high fish consumption had a 52% reduced risk of dying from any cause compared to those with less fish. Yet, no notable correlations were found with other sources of protein like eggs and dairy, different types of protein (both animal and plant), or omega-3 fatty acid levels.

The study’s analysis found that the beneficial effect of protein intake on mortality was independent of muscle mass. This is particularly noteworthy because the study included only participants who maintained their activities of daily living (ADLs), indicating that other factors besides muscle mass might also contribute to the observed association.

Implications of the Protein and Longevity Study

The findings of this study are groundbreaking. The results of this study suggest that protein and longevity are closely linked, especially from sources like fish. While the study focused on a specific demographic, its implications could be far-reaching. They suggest that a higher protein intake, especially from sources like fish, can play a role in reducing the risk of mortality in older adults. While the study focused on a specific demographic, its implications could be far-reaching.

However, like all research, this study has its limitations. The specific demographic of the participants, the relatively short follow-up period, and the potential for reverse causality are factors to consider when interpreting the results.

Practical Recommendations

For those looking to incorporate these findings into their daily lives:

  • Consider increasing your protein intake, especially from fish.
  • Always opt for high-quality protein sources, ensuring a balance between animal and plant-based options.


The recent study contributes to our understanding of protein and lifespan, emphasizing its importance in overall health and mortality risk. Balancing protein intake, taking various factors into account, is crucial for healthy aging. The complexity of protein’s effects on lifespan is highlighted by these findings, indicating the need for further research on the activation of growth hormone and growth factor IGF-1 to comprehend the relationship between protein and longevity fully.

Dietary choices play a significant role in protein and longevity. The recent protein intake and mortality study offers a fresh perspective on the benefits of protein, especially from fish, in promoting a longer, healthier life. As we unravel the complexities of nutrition, it’s clear that a balanced, thoughtful approach to our diet can pave the way for a brighter, healthier future.


Beasley, J. M., Shikany, J. M., & Thomson, C. A. (2013). The Role of Dietary Protein Intake in the Prevention of Sarcopenia of Aging. Nutrition in Clinical Practice.

Budhathoki, S., Sawada, N., Iwasaki, M., Yamaji, T., Goto, A., Kotemori, A., Ishihara, J., Takachi, R., Charvat, H., Mizoue, T., Iso, H., & Tsugane, S. (2019). Association of Animal and Plant Protein Intake With All-Cause and Cause-Specific Mortality in a Japanese Cohort. JAMA Intern Med, 179(11), 1509-1518.

Chan, R., Leung, J., & Woo, J. (2019). High Protein Intake Is Associated with Lower Risk of All-Cause Mortality in Community-Dwelling Chinese Older Men and Women. The journal of nutrition, health & aging, 23(10), 987-996.

Deutz, N. E. P., Bauer, J., Barazzoni, R., Biolo, G., Boirie‌, Y., Bosy‐Westphal, A., Cederholm, T., Cruz-Jentoft, A. J., Krznarić, Ž., Nair, K. S., Singer, P., Teta, D., Tipton, K. D., & Calder, P. C. (2014). Protein Intake and Exercise for Optimal Muscle Function With Aging: Recommendations From the ESPEN Expert Group. Clinical Nutrition.

Kitada, M., Ogura, Y., Monno, I., & Koya, D. (2019). The Impact of Dietary Protein Intake on Longevity and Metabolic Health. Ebiomedicine.

Kurata, H., Meguro, S., Abe, Y., Sasaki, T., Asakura, K., Arai, Y., & Itoh, H. (2023). Dietary protein intake and all-cause mortality: results from The Kawasaki Aging and Wellbeing Project. BMC Geriatr, 23(1), 479.


Naghshi, S., Sadeghi, O., Willett, W. C., & Esmaillzadeh, A. (2020). Dietary Intake of Total, Animal, and Plant Proteins and Risk of All Cause, Cardiovascular, and Cancer Mortality: Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies. BMJ.

Pedersen, A. N., Kondrup, J., & Børsheim, E. (2013). Health effects of protein intake in healthy adults: a systematic literature review. Food & Nutrition Research, 0(0).

Schwingshackl, L., Schwedhelm, C., Hoffmann, G., Lampousi, A.-M., Knüppel, S., Iqbal, K., Bechthold, A., Schlesinger, S., & Boeing, H. (2017). Food groups and risk of all-cause mortality: a systematic review and meta-analysis of prospective studies1,2. The American Journal of Clinical Nutrition, 105(6), 1462-1473.

Song, M., Fung, T. T., Hu, F. B., Willett, W. C., Longo, V. D., Chan, A. T., & Giovannucci, E. L. (2016). Association of Animal and Plant Protein Intake With All-Cause and Cause-Specific Mortality. JAMA internal medicine176(10), 1453–1463.

Yu, T., Oguma, Y., Asakura, K., Abe, Y., & Arai, Y. (2023). Association between dietary patterns and subjective and objective measures of physical activity among Japanese adults aged 85 years and older: a cross-sectional study. British Journal of Nutrition, 130(6), 1088-1097.

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