Association between household food insecurity and mortality in Canada: a population-based retrospective cohort study

BACKGROUND: Food insecurity affects 1 in 8 households in Canada, with serious health consequences. We investigated the association between household food insecurity and all-cause and cause-specific mortality.

METHODS: We assessed the food insecurity status of Canadian adults using the Canadian Community Health Survey 2005–2017 and identified premature deaths among the survey respondents using the Canadian Vital Statistics Database 2005–2017. Applying Cox survival analyses to the linked data sets, we compared adults’ all-cause and cause-specific mortality hazard by their household food insecurity status.

RESULTS: Of the 510 010 adults sampled (3 390 500 person-years), 25 460 died prematurely by 2017. Death rates of food-secure adults and their counterparts experiencing marginal, moderate and severe food insecurity were 736, 752, 834 and 1124 per 100 000 person-years, respectively. The adjusted hazard ratios (HRs) of all-cause premature mortality for marginal, moderate and severe food insecurity were 1.10 (95% confidence interval [CI] 1.03–1.18), 1.11 (95% CI 1.05–1.18) and 1.37 (95% CI 1.27–1.47), respectively. Among adults who died prematurely, those experiencing severe food insecurity died on average 9 years earlier than their food-secure counterparts (age 59.5 v. 68.9 yr). Severe food insecurity was consistently associated with higher mortality across all causes of death except cancers; the association was particularly pronounced for infectious-parasitic diseases (adjusted HR 2.24, 95% CI 1.42–3.55), unintentional injuries (adjusted HR 2.69, 95% CI 2.04–3.56) and suicides (adjusted HR 2.21, 95% CI 1.50–3.24).

INTERPRETATION: Canadian adults from food-insecure households were more likely to die prematurely than their food-secure counterparts. Efforts to reduce premature mortality should consider food insecurity as a relevant social determinant.