Toward a Better Understanding of Listeriosis Risk among Older Adults in the United States: Characterizing Dietary Patterns and the Sociodemographic and Economic Attributes of Consumers with These Patterns

Abstract

Older adults are at higher risk of invasive listeriosis compared with the general population. Some foods are more likely than others to be contaminated with or to contain high levels of Listeria monocytogenes. The objectives of this study were to (i) determine dietary consumption patterns among older adults in the United States; (ii) evaluate sociodemographic and economic characteristics of older adults associated with each pattern; (iii) determine intake of foods associated with larger relative risk of listeriosis within these patterns; and (iv) rank these patterns based on risk. Data related to older adults (age 60 and older) participating in the cross-sectional National Health and Nutrition Examination Surveys (NHANES) 2009 to 2010, 2011 to 2012, and 2013 to 2014 (n = 4,967) were included in these analyses. Cluster analysis was used to define dietary patterns based on 24-h dietary recalls from day 1 and day 2. Mean intake of foods associated with higher risk of listeriosis was examined within each pattern, and analysis of variance with Dunnett's method of adjustment was used to evaluate significant differences in mean intake of foods. Patterns were ranked based on relative risk of listeriosis, using outbreak illness attribution data. Five distinct dietary patterns were identified. Patterns ranked at highest relative risk of listeriosis, based on U.S. outbreak illness attribution data, were characterized by relatively higher intakes of fruits, vegetables, and cheeses (∼13% respondents) or cereal, milk, and yogurt (∼14% respondents). Individuals consuming these dietary patterns differed in sex, race, food security, self-rated diet quality, and self-rated health. Cluster analysis, despite methodological limitations, provides new information on consumption, sociodemographic, and economic characteristics of subgroups within susceptible populations, which may be used to target educational messages.