Adequate Protein Intake on Comprehensive Frailty in Older Adults: Kyoto-Kameoka Study

Area of Science:

• Gerontology
• Nutritional Science
• Public Health

Background:

• Defining adequate protein intake for older adults is crucial for maintaining health and preventing frailty.
• Frailty is a significant concern in aging populations, impacting morbidity and mortality.
• Previous research has not definitively established optimal protein intake levels for older adults, especially considering sex differences.

Purpose of the Study:

• To examine the association between calibrated protein intake and comprehensive frailty in older Japanese adults.
• To determine sex-specific optimal protein intake levels for reducing frailty prevalence.

Main Methods:

• A cross-sectional study utilizing baseline data from 5679 Japanese participants aged 65 years and older.
• Calibrated protein intake was assessed using food frequency questionnaires and 7-day dietary records.
• Comprehensive frailty was evaluated using the 25-item Kihon Checklist (KCL), with frailty defined as a KCL score of ≥7 points.

Main Results:

• Calibrated protein intake was inversely associated with comprehensive frailty in older adults.
• A U-shaped association between protein intake and frailty was observed in men, while an L-shaped association was found in women.
• Optimal protein intake levels for low frailty prevalence were higher than current recommendations, varying by sex and intake metric (e.g., % energy, g/kg body weight).

Conclusions:

• A non-linear relationship exists between calibrated protein intake and frailty in older adults, with sex-specific patterns.
• The findings suggest that adequate protein intake, particularly higher amounts than currently recommended, may be beneficial for preventing frailty in healthy older Japanese adults.
• Sex-specific dietary recommendations for protein intake may be warranted to optimize health outcomes in aging populations.