Fruit and vegetable intake and risk of hip fracture: a cohort study of Swedish men and women

Abstract

Dietary guidelines recommend a daily intake of 5 servings of fruits and vegetables. Whether such intakes are associated with a lower risk of hip fracture is at present unclear. The aim of the present study was to investigate the dose-response association between habitual fruit and vegetable intake and hip fracture in a cohort study based on 40,644 men from the Cohort of Swedish Men (COSM) and 34,947 women from the Swedish Mammography Cohort (SMC) (total n = 75,591), free from cardiovascular disease and cancer, who answered lifestyle questionnaires in 1997 (age 45 to 83 years). Intake of fruits and vegetables (servings/day) was assessed by food frequency questionnaire and incident hip fractures were retrieved from the Swedish Patient Register (1998 to 2010). The mean follow-up time was 14.2 years. One-third of the participants reported an intake of fruits and vegetables of >5 servings/day, one-third reported >3 to ≤5 servings/day, 28% reported >1 to ≤3 servings/day, and 6% reported ≤1 serving/day. During 1,037,645 person-years we observed 3644 hip fractures (2266 or 62% in women). The dose-response association was found to be strongly nonlinear (p < 0.001). Men and women with zero consumption had 88% higher rate of hip fracture compared with those consuming 5 servings/day; adjusted hazard ratio (HR) was 1.88 (95% CI, 1.53 to 2.32). The rate was gradually lower with higher intakes; adjusted HR for 1 versus 5 servings/day was 1.35 (95% CI, 1.21 to 1.58). However, more than 5 servings/day did not confer additionally lower HRs (adjusted HR for 8 versus 5 servings/day was 0.96; 95% CI, 0.90 to 1.03). Similar results were observed when men and women were analyzed separately. We conclude that there is a dose-response association between fruit and vegetable intake and hip fracture such that an intake below the recommended five servings/day confers higher rates of hip fracture. Intakes above this recommendation do not seem to further lower the risk.

Keywords: EPIDEMIOLOGY; FRUITS AND VEGETABLES; HIP FRACTURE; NUTRITION; OSTEOPOROSIS.