Research paper
The effects of a two‐year randomized, controlled trial of whey protein supplementation on bone structure, IGF‐1, and urinary calcium excretion in older postmenopausal women
Study answer
What this study found
Overall, 30 g/day whey protein increased serum IGF-1 but did not improve or worsen bone mass or strength over 2 years in this protein-replete population. Serum IGF-1 was higher in the protein group at year 1 by 7.3% ± 2.5% (p = .004) and at year 2 by 8.0% ± 3.3% (p = .016). There were no group-by-time interactions for hip bone variables or femoral neck engineering strength, and no between-group differences in changes in bone density or strength. Twenty-four-hour urinary calcium excretion increased over time in both groups at 1 year, and at 2 years it was 13.4% ± 7.3% higher than placebo in…
- Study & population
- Randomized controlled trial in healthy, ambulant postmenopausal women aged 70-80 years from metropolitan Perth, Western Australia.
- Intervention
- The active intervention was a daily 250-mL oral skim milk-based whey protein drink, reconstituted from powder to provide 30 g protein, 600 mg calcium, and 3.2 kJ/mL.
- Key limitation
- Findings come from healthy older women with relatively high baseline protein intake, limiting generalizability to protein-deficient or other populations.
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Open PDFOriginal abstract
The effects of dietary protein on bone structure and metabolism have been controversial, with evidence for and against beneficial effects. Because no long‐term randomized, controlled studies have been performed, a two‐year study of protein supplement…