Macronutrients Intake and Incident Frailty in Older Adults: A Prospective Cohort Study

Background: Only a few studies have assessed the association between protein intake and frailty incidence and have obtained inconsistent results. This study examined the association of protein and other macronutrient intake with the risk of frailty in older adults.

Methods: A prospective cohort of 1,822 community-dwelling individuals aged 60 and older was recruited in 2008-2010 and followed-up through 2012. At baseline, food consumption was assessed with a validated, computerized face-to-face diet history. In 2012, individuals were contacted again to ascertain incident frailty, defined as the presence of at least three of the five Fried criteria: low physical activity, slowness, unintentional weight loss, muscle weakness, and exhaustion. Analyses were performed using logistic regression and adjusted for the main confounders, including total energy intake.

Results: During a mean follow-up of 3.5 years, 132 persons with incident frailty were identified. The odds ratios (95% confidence interval) of frailty across increasing quartiles of total protein were 1.00, 0.55 (0.32-0.93), 0.45 (0.26-0.78), and 0.41 (0.23-0.72); p trend: .001. The corresponding figures for animal protein intake were 1.00, 0.68 (0.40-1.17), 0.56 (0.32-0.97), and 0.48 (0.26-0.87), p trend: .011. And for intake of monounsaturated fatty acids (MUFAs), the results were 1.00, 0.66 (0.37-1.20), 0.54 (0.28-1.02), and 0.50 (0.26-0.96); p trend: .038. No association was found between intake of vegetable protein, saturated fats, long-chain ω-3 fatty acids, α-linolenic acid, linoleic acid, simple sugars, or polysaccharides and the risk of frailty.

Conclusion: Intake of total protein, animal protein, and MUFAs was inversely associated with incident frailty. Promoting the intake of these nutrients might reduce frailty.