Adherence to the healthy Nordic food index and total and cause-specific mortality among Swedish women

Abstract

Several healthy dietary patterns have been linked to longevity. Recently, a Nordic dietary pattern was associated with a lower overall mortality. No study has, however, investigated this dietary pattern in relation to cause-specific mortality. The aim of the present study was to examine the association between adherence to a healthy Nordic food index (consisting of wholegrain bread, oatmeal, apples/pears, root vegetables, cabbages and fish/shellfish) and overall mortality, and death by cardiovascular disease, cancer, injuries/suicide and other causes. We conducted a prospective analysis in the Swedish Women’s Lifestyle and Health cohort, including 44,961 women, aged 29–49 years, who completed a food frequency questionnaire between 1991–1992, and have been followed up for mortality ever since, through Swedish registries. The median follow-up time is 21.3 years, and mortality rate ratios (MRR) were calculated using Cox Proportional Hazards Models. Compared to women with the lowest index score (0–1 points), those with the highest score (4–6 points) had an 18 % lower overall mortality (MRR 0.82; 0.71–0.93, p < 0.0004). A 1-point increment in the healthy Nordic food index was associated with a significantly lower risk of all-cause mortality: 6 % (3–9 %), cancer mortality: 5 % (1–9 %) and mortality from other causes: 16 % (8–22 %). When examining the diet components individually, only wholegrain bread and apples/pears were significantly inversely associated with all-cause mortality. We observed no effect-modification by smoking status, BMI or age at baseline. The present study encourages adherence to a healthy Nordic food index, and warrants further investigation of the strong association with non-cancer, non-cardiovascular and non-injury/suicide deaths.