The overall evidence indicates that milk and milk products help to maintain bone mineral density and prevent bone loss in adults. Bone mineral density is considered the most important risk factor for fragility fractures. Protecting bone mass is fundamental to preventing osteoporosis, fragility fractures and disability in older and elderly adults.
- Milk products, including milk, yogurt and cheese, are associated with improved bone mineral density.
- Milk product consumption attenuates bone loss and is associated with a lower risk of osteoporosis.
- Dairy protein is associated with increased bone mineral density; plant protein is associated with decreased bone mineral density.
A 2019 systematic review and meta-analysis of randomized controlled trials, prospective cohort and case-control studies examined the effect of fermented milk products on bone health indicators in postmenopausal women and found:1
- Yogurt and cheese decreased bone resorption markers;
- Yogurt was associated with a 24% reduced risk of hip fractures;
- Cheese had either no association or a protective association with osteoporosis.
A 2015 meta-analysis of 15 randomized controlled trials (n=1,533) by Tai et al. examined whether increasing calcium from dietary sources affects bone mineral density in adults over 50 years of age.2
- Increasing calcium intake from dietary sources led to a small increase in bone mineral density at all sites except the forearm.
- Similar results were obtained when the analyses were restricted to calcium intake from dairy products only.
A 2013 meta-analysis of randomized controlled trials investigated the effects of milk consumption on bone mass and bone turnover markers. The analysis by Ma et al. consisted of 11 studies that included 2,397 participants (adults and children). The authors concluded that milk has a favorable impact on bone density and attenuates bone loss.3 Compared to the control group, those who consumed milk had an increase in bone mineral content, total body bone mineral density and a decrease in bone turnover markers associated with bone loss.
A 2019 systematic review and meta-analysis of prospective cohort and case-control studies on dairy foods and fracture risk by Matía-Martín et al. assessed dairy food consumption and changes in bone mineral density.4 The authors note that the available evidence suggests that lower dairy food consumption is linked with lower bone mineral density over time. Milk and dairy foods play a beneficial role in protecting bones throughout life. Positive associations were found between:
- Milk intake during infancy and adolescence and hip bone mineral density in women;
- Milk intake after 65 years of age and bone mineral density in the arm at the wrist.
In 2018, Biver et al. published findings from their longitudinal analysis of bone microstructure in older community-dwelling women. 5 This prospective cohort study followed 483 healthy postmenopausal women from the Geneva Retirees Cohort. At baseline, women who consumed fermented dairy products (i.e. yogurt, fresh cheese, quark, kefir) had larger bone size and those who consumed milk and fermented dairy products had a lower prevalence of osteoporosis. Over the course of about 3 years follow-up, this study found that:
- Fermented dairy product consumption was associated with less bone loss, independently of total energy, calcium and protein intakes;
- Women who consumed fermented dairy products also had lower levels of markers associated with bone loss.
In 2015, Langsetmo et al. published findings from the Canadian Multicentre Osteoporosis Study (CaMos). 6 This prospective cohort study assessed protein intake and relationships between different sources of protein and bone mineral density in 6,510 men and women. In adults 50 years and older followed over the course of a 5-year period, this study found that:
- Dairy protein was associated with increased bone mineral density;
- Plant protein was associated with decreased bone mineral density.
The totality of the evidence indicates that dairy consumption is beneficial for bone health in older and elderly adults.
Consumption of milk and milk products improves bone mineral density and decreases bone loss. Research indicates that a number of nutrients including calcium, vitamin D and the protein in dairy foods support bone health.
The preservation of bone mineral density plays an important role in preventing osteoporosis and reducing the risk of fragility fractures.
- Ong AM et al. Fermented milk products and bone health in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials, prospective cohorts, and case-control studies. Adv Nutr 2019;00:1-15.
- Tai V et al. Calcium intake and bone mineral density: systematic review and meta-analysis. BMJ 2015;351:h4183.
- Ma DF et al. Milk intake increases bone mineral content through inhibiting bone resorption: meta-analysis of randomized controlled trials. ESPEN J 2013;8:e1-e7.
- Matía-Martín P et al. 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. Adv nutr 2019;10:S120-S143.
- Biver E et al. Fermented dairy products consumption is associated with attenuated cortical bone loss independently of total calcium, protein, and energy intakes in healthy postmenopausal women. Osteoporos Int 2018;29(8):1771–82.
- Langsetmo L et al. Associations of protein intake and protein source with bone mineral density and fracture risk: A population-based cohort study. J Nutr Health Aging 2015;19:861-868.