The association between medication use and lifestyle factors in independently living older people: impact of Mediterranean diet and physical activity

Objectives: Adherence to the Mediterranean diet (MedDiet) and engagement in physical activity (PA) are associated with a lower risk of chronic disease, yet their relationship with medication use in older adults is less clear. This study examined cross-sectional associations between MedDiet adherence, PA levels, and medication use, including polypharmacy, in independently living older Australians. 

Design: A cross-sectional observational study 

Setting and participants: Baseline data were drawn from the MedWalk trial, including 161 participants (119 females, 42 males; aged 60–90 years) residing in independent living facilities in Adelaide and Melbourne, and the wider Melbourne community. 

Measurements: Adherence to the MedDiet was assessed using the 14-item Mediterranean Diet Adherence Screener (MEDAS). PA was objectively measured via accelerometry and categorized as low (<150 min/week), moderate (150–<300 min/week), or high (≥300 min/week) of moderate-to-vigorous PA. Medication use was self-reported and coded using Anatomical Therapeutic Chemical (ATC) classifications. Polypharmacy was defined as use of ≥5 medications. Logistic and negative binomial regression analyses were adjusted for age, sex, education, and BMI. 

Results: Moderate and high PA were associated with significantly lower odds of polypharmacy compared with low PA (AOR=0.37, p = 0.047; AOR=0.08, p = 0.022, respectively). High PA was also associated with a reduced total number of medications (exp(B)=0.44, p = 0.018) and fewer cardiovascular medications (AOR=0.29, p = 0.042). Each additional point in MedDiet adherence was associated with reduced use of alimentary tract and metabolism medications (AOR=0.78, p = 0.016), though no association was found with total medication use or polypharmacy. 

Conclusion: In this cross-sectional study, higher PA was consistently associated with reduced polypharmacy and fewer medications, while greater MedDiet adherence was linked to reduced use of metabolic medications. Lifestyle practices may influence medication use patterns in later life. Larger longitudinal studies are needed to clarify causality and inform strategies to reduce polypharmacy through promotion of healthy lifestyle behaviors.