Milk drinking and risk of hip fracture: the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS)

Milk provides energy and nutrients considered protective for bone. Meta-analyses of cohort studies have found no clear association between milk drinking and risk of hip fracture, and results of recent studies are contradictory. We studied the association between milk drinking and hip fracture in Norway, which has a population characterised by high fracture incidence and a high Ca intake. Baseline data from two population-based cohorts were used: the third wave of the Norwegian Counties Study (1985-1988) and the Five Counties Study (2000-2002). Diet and lifestyle variables were self-reported through questionnaires. Height and weight were measured. Hip fractures were identified by linkage to hospital data with follow-up through 2013. Of the 35 114 participants in the Norwegian Counties Study, 1865 suffered a hip fracture during 613 018 person-years of follow-up. In multivariable Cox regression, hazard ratios (HR) per daily glass of milk were 0 center dot 97 (95 % CI 0 center dot 92, 1 center dot 03) in men and 1 center dot 02 (95 % CI 0 center dot 96, 1 center dot 07) in women. Of 23 259 participants in the Five Counties Study, 1466 suffered a hip fracture during 252 996 person-years of follow-up. HR for hip fractures per daily glass of milk in multivariable Cox regression was 0 center dot 99 (95 % CI 0 center dot 92, 1 center dot 07) in men and 1 center dot 02 (95 % CI 0 center dot 97, 1 center dot 08) in women. In conclusion, there was no overall association between milk intake and risk of hip fracture in Norwegian men and women.