Dietary quality modifies the association between multimorbidity and change in mobility limitations among older Americans.

To identify potentially modifiable risk-factors in the age-related disablement process, we examined the association between change in mobility limitations and multimorbidity and how dietary quality moderates this association. Information from 3320 adults aged 65 and older in 2012 was drawn from the Health and Retirement Study and the Health Care and Nutrition Study. Mobility limitations reported in 2012 and change in mobility limitations from 2012 to 2014 were regressed on multimorbidity measured as number of chronic conditions in 2012, dietary quality measured in 2013 using the Alternative Healthy Eating Index-2010 (AHEI-2010), and their interaction term using Poisson regression. Respondents reported an average of 2.9 (SD, 2.9) mobility limitations in 2012 and 3.1 (SD, 3.0) mobility limitations in 2014, an average of 2.64 (SD, 1.4) chronic conditions in 2012, and mean AHEI-2010 score in 2013 of 57.1 (SD, 10.9). Greater AHEI-2010 scores were associated with fewer mobility limitations at baseline (p < .001) and slower progression of mobility limitations over the two-year observational window (p < .001). For those with AHEI-2010 scores ≥48.4, dietary quality appeared to moderate the association between multimorbidity and change in mobility limitations. These results suggest that improving dietary quality may be an effective means of reducing the progression of mobility limitations among older adults and that dietary quality may modify the effect of multimorbidity on progressive disablement. Our work adds to research supporting dietary quality as a potentially intervenable factor in the reduction of disablement in aging populations.