Effects of Milk and Dairy Products on the Prevention of Osteoporosis and Osteoporotic Fractures in Europeans and Non-Hispanic Whites from North America: A Systematic Review and Updated Meta-Analysis

Abstract

Nutrition plays an important role in bone health. The aim of our study was to update the evidence regarding dairy intake, osteoporotic fracture (OF) risk, and prospective bone mass density (BMD) evolution assessed by dual-energy X-ray absorptiometry in Europeans and non-Hispanic whites from North America. A systematic search was conducted in MEDLINE, EMBASE, and Scopus for papers published from 1 January, 2000 to 30 April, 2018. The eligibility criteria were as follows: healthy adults; measurable dairy exposure; hip, vertebral, wrist or OF as outcomes; and cohort or case-control studies. Two independent investigators conducted the search and the data extraction. A pooled analysis was conducted with random-effects models. Publication bias and meta-regression were considered. Ten cohort studies relating to OF risk were selected for meta-analysis. Three papers reporting BMD changes associated with dairy intake could not be aggregated in the meta-analysis. The pooled HRs of the highest compared with the lowest levels of dairy intake were 0.95 (95% CI: 0.87, 1.03; I 2 = 82.9%; P-heterogeneity < 0.001) for OF at any site; 0.87 (95% CI: 0.75, 1.01; I 2 = 86.7%; P-heterogeneity < 0.001) for hip fractures; and 0.82 (95% CI: 0.68, 0.99; I 2 = 0.0%; P-heterogeneity = 0.512) for vertebral fractures. Concerning BMD, the selected studies described a 1.7-3% lower hip BMD in young and postmenopausal women with poor intake of milk in their youth, a positive relationship between baseline milk ingestion and the percentage of trochanter BMD change in elderly people, and a positive correlation between milk consumption and BMD change at the radius in women aged >65 y. In conclusion, in the studied population, the highest consumption of dairy products did not show a clear association with the total OF or hip fracture risks; however, a diminished risk of vertebral fracture could be described. The results regarding BMD change were heterogeneous and did not allow for a definitive conclusion. Adv Nutr 2019;10:S120-S143.

Comparison of methodological quality between the 2007 and 2019 Canadian dietary guidelines

“…However, the removal of the previous 2007 dairy food group in the new guidelines remains unclear, even though osteoporosis was one of the health outcomes included in the evidence review for the 2019 guidelines (8) . From the literature, we have seen consistent findings in the effect of dairy products on bone growth in children (20,21) and on lowering the risk of osteoporosis and fractures in older adults (22) . Future work is needed to understand the impact of the removal of dairy recommendations on bone health across different age groups.…”

Milk Consumption for the Prevention of Fragility Fractures

“…The potential bias by the corporate funding of trials or even speaker fees or travel grants should not be neglected [ 141 , 142 , 143 ]. Of 22 review articles (in English, found in PubMed by the search term “review AND (milk OR dairy) AND (osteoporosis OR fracture)” and limited to those papers with milk, dairy, or other dairy products in the titles published in 2016–2020) published in the past years, 13 papers [ 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 ] were written by at least one author with links to the dairy industry or dairy associations, whereas the authors of nine papers [ 4 , 9 , 10 , 157 , 158 , 159 , 160 , 161 , 162 ] did not report any such conflicts of interest. Although not explored, the proportion of opinion papers, comments, and letters to the editors with conflicts of interest is likely to be higher.…”

Impact of whole dairy matrix on musculoskeletal health and aging–current knowledge and research gaps

“…Two case-control studies including infants (10-20 months old), children, adolescents, and young adults (up to 20 years) found impaired bone strength and higher fracture risk among those not consuming dairy products [72,73]. However, evidence for a positive association between dairy food consumption and fracture risk reduction is inconsistent, possibly due to methodological differences in study design [74,75]. Issues include lack of consistency in which dairy foods are included in analyses, number, timing, and quality of dietary assessments, and validation of fractures.…”

“…In the Danish National Diet and Nutrition Survey, the differences in nutrient intake, though not as large, are still present [80]. This may contribute to why results from observational studies using different time points of dietary assessment have inconsistent results [74,81].…”

“…Meta-analyses of observational studies potentially carry the risk of bias due to the assumption of serving sizes being equal, though they also differ substantially between countries [56]. This is the case in a newly published meta-analysis where the effects of cheese and yoghurt consumption from a Swedish and a US population are included in the same analyses, although consumption of cheese is twice as high and yoghurt is more than 40 times higher in the Swedish compared to the US population [74,75,81]. The same observational study reports increased fracture risk and a 2% increased mortality with a higher milk intake, but fails to draw attention to a reduction of 10% in risk of fracture with increased cheese and fermented dairy intake [75].…”