Dietary diversity offsets the adverse mortality risk among older indigenous Taiwanese

The extent to which health and survival inequality between indigenous and nonindigenous older Taiwanese is associated with diet is uncertain.

Participants from the Elderly Nutrition and Health Survey in Taiwan (1999-2000) formed this cohort. Dietary information was collected by 24-hr recall and simplified food frequency questionnaire. Dietary quality was assessed by dietary diversity score (DDS, 0-6). Annual medical service utilization and expenditure were derived from National Health Insurance claims until 2006. Survivorship was ascertained from the National Death Registry until 2008. Cox proportional- hazards models were used to determine the association between aboriginality and mortality in conjunction with dietary diversity.

Indigenes (n=156) compared with nonindigenes (n=1182) significantly differed in socio-demography, behaviors and chronic disease prevalences. For up to 8 years, indigenes had a higher mortality rate (46.2% vs 33.6%, p=0.003). Indigenes' nutrient intakes were less for polyunsaturated fat, dietary fiber, vitamins and minerals (but more sodium); food intakes more for meat, with less cooking oil, dairy products and fruits; and a lower DDS, (3.61 vs 4.54). They had a 41% higher mortality risk (HR: 1.41, 95% CI: 1.09-1.81, p=0.008). Control for demographic variables did not change the findings. However, the increase in HR was substantially attenuated by the inclusion of DDS (HR: 1.15, 95% CI: 0.88-1.49, p=0.316). There was no significant interaction between aboriginality and DDS on mortality (p=0.673).

Older indigenous Taiwanese have a higher mortality risk than their majority counterparts. Irrespective of aboriginality, the more diverse diet is associated with a lower risk of mortality.