Dietary Micronutrient Adequacy and Risk of Multimorbidity in Community-dwelling Older Adults

Abstract

Background: Multimorbidity refers to the coexistence of multiple chronic health conditions. The effect of nutritional adequacy on multimorbidity is mostly unknown.

Objective: The aim of this study was to assess the prospective association between dietary micronutrient adequacy and multimorbidity among community-dwelling older adults.

Methods: This cohort study included 1461 adults aged ≥65 y from the Seniors-ENRICA II cohort. Habitual diet was assessed at baseline (2015-2017) with a validated computerized diet history. The intakes of 10 micronutrients (calcium, magnesium, potassium, vitamins A, C, D, E, zinc, iodine, and folate) were expressed as percentages relative to the dietary reference intakes, with higher scores indicating greater adequacy. Dietary micronutrient adequacy was computed as the average of all the nutrient scores. Information on medical diagnosis was obtained from the electronic health records up to December 2021. Conditions were grouped into a comprehensive list of 60 categories and occurrence of multimorbidity was defined as having ≥6 chronic conditions. Analyses were conducted using Cox proportional hazard models adjusted for relevant confounders.

Results: The mean age was 71.0 y (SD: 4.2) and 57.8% of participants were males. During a median follow-up of 4.79 y, we documented 561 incident cases of multimorbidity. Participants in the highest (85.8%-97.7%) versus the lowest tertile (40.1%-78.7%) of dietary micronutrient adequacy had a low risk of multimorbidity [fully adjusted hazard ratio (95% confidence interval): 0.75 (0.59-0.95); P-trend: 0.02]. A 1-SD increment in minerals and vitamins adequacy was associated with a low risk of multimorbidity, although estimates were attenuated after additional adjustment for the opposite subindex [minerals subindex: 0.86 (0.74-1.00); vitamins subindex: 0.89 (0.76-1.04)]. No differences were observed by strata of sociodemographic and lifestyle factors.

Conclusion: A high micronutrient index score was associated with low risk of multimorbidity. Improving the dietary micronutrient adequacy could prevent multimorbidity among older adults.

Clinical trial registry: clinicaltrials.govNCT03541135.

Keywords: chronic disease; diet quality; micronutrients; minerals; multimorbidity; older adults; vitamins.