Hip fractures constitute a major and growing public health problem among older adults worldwide. Hip fractures are associated with considerable disability and reduced survival and, although they represent less than 20% of all osteoporotic fractures, they account for the majority of fracture-related health care expenditure and mortality in men and women over the age of fifty¹. Among environmental factors amenable to change, diet may play an important role in hip fracture prevention.

Fruit and vegetable intake and hip fracture risk

High fruit and vegetable (F&V) intake has been associated with increased bone mineral density, decreased bone loss and reduced bone turnover, as well as, reduced incidence of hip fractures and fractures in other sites^2-4. These associations are based on observational studies, mostly not prospective in design, conducted among communitydwelling elderly populations and post-menopausal women. In order to explore further the role of F&V intake in hip fracture risk, we have tested the hypothesis that high intake of F&V may be associated with reduced incidence of hip fracture in a large sample of older men and women from Europe and the United States (US) who were followed-up prospectively until the diagnosis of hip fracture.

Study design

The Consortium on Health and Ageing: Network of Cohorts in Europe and the United States (CHANCES) provided a unique opportunity to investigate the specific hypothesis using harmonized, defined within the consortium, data⁵. CHANCES is a collaborative, large scale, integrating project funded by the European Commission within the Seventh Framework Programme and coordinated by Hellenic Health Foundation in Greece (http://www.chancesfp7.eu). A total of 142,018 individuals (among which 116,509 women), aged ≥60 years old, from five prospective cohorts with relevant data participating in CHANCES: European Prospective Investigation into cancer and Nutrition (EPIC)-Elderly Greece and EPIC-Elderly Umea from Sweden, the Swedish Mammography Cohort (SMC) and the Cohort Of Swedish Men (COSM) studies and the Nurses’ Health Study (NHS) from US were included in the study. F&V intake was assessed by validated, cohort-specific, foodfrequency questionnaires. During follow-up a total of 5,552 incident hip fractures were recorded. Hip fractures were further ascertained through national patient registers or telephone interviews/questionnaires. For the purpose of this analysis F&V intake was expressed in servings/day.
The size of the serving was set to 80 grams in the Greek and Swedish cohorts, whereas in NHS, servings ranged in grams according to the specific F&V. Adjusted hazard ratios (HR) derived by Cox proportionalhazards regression were estimated for each cohort and subsequently pooled using random-effects meta-analysis.

Low F&V intake is associated with increased hip fracture incidence in comparison to moderate intakes

We found that individuals with low daily intake of F&V equivalent to one or less servings had a 39% higher risk of hip fracture in comparison to individuals with moderate daily intakes ranging from more than three to five servings [pooled adjusted HR:1.39, 95% Confidence Intervals (CIs): 1.20, 1.58]. Intakes of more than five servings/day were not associated with lower hip fracture risk. With respect to daily intake of vegetables alone, intake of one serving or less was associated with a 12% higher hip fracture risk in comparison to intake of more than one to three servings/day (pooled adjusted HR:1.12, 95% CIs: 1.03 to 1.21), whereas intake of similar servings of fruit was not associated with hip fracture risk. These findings derived after controlling for important potential confounders such as physical activity, body mass index, alcohol and energy intake, smoking and parameters of socio-economic status, were consistent across the cohorts and were more evident among women.
Several underlying biological mechanisms have been proposed in order to explain the potential beneficial effects of F&V in hip fracture prevention. Components abundant in these foods with antioxidant (e.g vitamins A, C, E, K, carotenoids) and anti-inflammatory properties (e.g. flavonoids) seem to be involved in the bone remodeling sequence or in body’s inflammatory response. Both oxidative stress and inflammation have been implicated in the pathogenesis of bone loss^6-8. Furthermore, the beneficial effects of F&V on health in general, seem to be attributed to the synergies of their bioactive components and their interaction with whole foods, as well as to the specific amounts consumed and not to the intake of individual nutrients as shown in clinical trials evaluating the health effects of specific dietary supplements⁹.

Conclusions
Based on the findings of this study daily consumption of moderate amounts of F&V may prevent hip fractures in older adults. Also, older adults that consume one or less servings of F&V per day may benefit from raising their intakes to moderate amounts in order to reduce their hip fracture risk.

*This work, derived from the CHANCES project, was supported by the FP7 framework programme of DG-RESEARCH in the European Commission [Grant number:
HEALTH-F3-2010-242244].

Based on: Benetou V, Orfanos P, Feskanich D, Michaëlsson K, Pettersson-Kymmer U, Eriksson S, Grodstein F, Wolk A, Bellavia A, Ahmed LA, Boffeta P, Trichopoulou A (2016). Fruit and Vegetable Intake and Hip Fracture Incidence in Older Men and Women: The CHANCES Project. J Bone Miner Res, 31(9):1743-52.