Does the kind of protein you eat influence the quality of your aging? Dr. Layne Norton explored this in a recent cohort study in The American Journal of Clinical Nutrition, meaning that the study followed nearly 50,000 participants for about 30 years. (1)
Healthy Aging
Healthy aging was defined as aging absent 11 chronic diseases that lead to mortality and can significantly disrupt the quality of life. Those diseases include:
- Cancer (except for nonmelanoma skin cancer)
- Type 2 Diabetes
- Myocardial Infarction
- Coronary Artery Bypass Graft Surgery or Percutaneous Transluminal Coronary Angioplasty
- Congestive Heart Failure
- Stroke
- Kidney Failure
- Chronic Obstructive Pulmonary Disease
- Parkinson Disease
- Multiple Sclerosis
- Amyotrophic Lateral Sclerosis
Additionally, healthy aging encompasses “having no impairment in memory or physical function, and being in good mental health.”
Protein seems to have a beneficial effect as higher protein intakes were associated with healthier aging.
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The lower quartile of protein intake was about 57 grams per day (14 percent of total daily calories). The highest daily quartile was about 90 grams of protein (22 percent of total daily calories).
A confounding variable (i.e., a variable that researchers could not entirely control for) was that those with higher protein diets consumed fewer calories overall. This might be suggestive of protein’s satiety benefits, meaning those who ate more protein felt more full than their lower-protein counterparts and, therefore, consumed fewer calories throughout each day. Furthermore, those with higher-protein diets had lower alcohol consumption.
Types of Protein vs. Other Macronutrients
The study delves further into the benefits of various types of protein and how their health markers matched up against other macronutrients (e.g., fats and carbohydrates). Aside from total protein, the types of protein examined were animal protein, dairy protein, and plant protein.
Compared to refined carbohydrates, carbohydrates from whole grains, saturated fats, monounsaturated fats, and polyunsaturated fats, only the latter had comparable markers to the various proteins.
Polyunsaturated fats are the only one that came out looking good in this study compared to protein.
Generally speaking, substituting protein for any nutrient showed neutral or positive effects. Per Norton, “For every three percent increase in total protein intake, there was a five percent increase in the possibility of healthy aging” (i.e., free of the diseases listed above).
Plant protein showed the greatest increases in healthy aging benefits. However, Norton is not convinced that that indicates being better than dairy or animal protein because plant protein-based diets are likely to feature much more fiber, which this study did not account for. Fiber is well-researched enough to know that higher-fiber diets typically lower the risk of mortality-related diseases.
Bottom line: protein is good for healthy aging.
Reference
- Ardisson Korat, A. V., Shea, M. K., Jacques, P. F., Sebastiani, P., Wang, M., Eliassen, A. H., Willett, W. C., & Sun, Q. (2024). Dietary protein intake in midlife in relation to healthy aging – results from the prospective Nurses’ Health Study cohort. The American journal of clinical nutrition, 119(2), 271–282.
Featured image via Shutterstock/Asier Romero
