title: Prospective study of dietary Non Enzymatic Antioxidant Capacity on the risk of hip fracture in the elderly.
abstract: Dietary antioxidants may play an important role in the prevention of bone loss and associated fractures by reducing levels of oxidative stress. We prospectively investigated the association between dietary Non Enzymatic Antioxidant Capacity (NEAC) and the risk of hip fracture and whether this effect was modified by smoking.
  
  
  
  In the Swedish National March Cohort 13,409 men and women over the age of 55 who had not experienced cancer, cardiovascular disease or hip fracture, were followed through record-linkages from 1997 through 2010. NEAC was assessed by a validated food frequency questionnaire collected at baseline. We categorized the distribution of NEAC into sex-specific quartiles and used multivariable adjusted Cox proportional hazards regression models to estimate hazard ratios (HRs) with 95% confidence intervals (95% CI).
  
  
  
  During a mean follow-up time of 12.4years, we identified 491 incident cases of first hip fracture. Subjects in the highest quartile of dietary NEAC had a 39% lower risk of incident hip fracture compared to those in the lowest quartile (HR: 0.61; 95% CI: 0.44-0.85). The association was non-linear (p for non-linearity: 0.004) with a potential threshold between the first and the second quartile and no further risk reduction at higher levels of dietary NEAC. Due to a low smoking prevalence in our study population, we had limited power to detect effect modification between dietary NEAC and smoking on a multiplicative or additive scale.
  
  
  
  Higher dietary NEAC intake is associated with lower risk of hip fracture in the elderly.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, 171 77 Stockholm, Sweden. Electronic address: e.hantikainen@campus.unimib.it.
authors.forename: Essi
authors.initials: E
authors.lastname: Hantikainen
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, 171 77 Stockholm, Sweden. Electronic address: alessandra.grotta@ki.se.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Grotta
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, 171 77 Stockholm, Sweden. Electronic address: weimin.ye@ki.se.
authors.forename: Weimin
authors.initials: W
authors.lastname: Ye
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, 171 77 Stockholm, Sweden; Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA. Electronic address: hadami@hsph.harvard.edu.
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Room: E8527, Baltimore, MD 21205, USA. Electronic address: p.surkan@jhsph.edu.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Surkan
authors.affiliation: Functional Food and Metabolic Stress Prevention Laboratory, Center of Nutrition, Council for Agricultural Research and Economics, Via Ardeatina 546, 00100 Rome, Italy. Electronic address: mauro.serafini@entecra.it.
authors.forename: Mauro
authors.initials: M
authors.lastname: Serafini
authors.affiliation: Department of Surgical Sciences, Section of Orthopedics, Uppsala Clinical Research Center, Akademiska sjukhuset ing. 61 6 tr, 751 85 Uppsala, Sweden. Electronic address: karl.michaelsson@surgsci.uu.se.
authors.forename: Karl
authors.initials: K
authors.lastname: Michaëlsson
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, 171 77 Stockholm, Sweden; Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Edificio U7, Via Bicocca degli Arcimboldi 8, 20126 Milan, Italy. Electronic address: rino.bellocco@unimib.it.
authors.forename: Rino
authors.initials: R
authors.lastname: Bellocco
authors.affiliation: Clinical Epidemiology Unit, T2, Department of Medicine, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Department of Medicine, Karolinska University Hospital, Huddinge, C2:84, SE-141 86 Stockholm, Sweden. Electronic address: ylva.trolle@ki.se.
authors.forename: Ylva
authors.initials: Y
authors.lastname: Trolle Lagerros
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D016001:Confidence Intervals; D004032:Diet; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology*; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D000975:Antioxidants
keywords: Diet; Hip fracture; Oxidative stress; Smoking; Total Antioxidant Capacity