Around 20 per cent of women over the age of 70 are affected by osteoporosis and calcium supplementation is widely recommended as a preventative measure against fracture.
New research from Edith Cowan University (ECU), Curtin University and the University of Western Australia has found no evidence that calcium monotherapy increases the long-term risk for dementia, helping to dispel previous concerns about its potential negative effects on brain health in older women.
This study, which leveraged outcomes from prior research that provided calcium supplements or a placebo to 1,460 older women over a five-year period, found that the supplement did not increase the long-term risk of dementia.
"Calcium supplements are often recommended to prevent or manage osteoporosis," said ECU PhD student Ms Negar Ghasemifard.
Around 20 per cent of women over the age of 70 are affected by osteoporosis and calcium supplementation is widely recommended as a preventative measure against fracture.
"Previous research has raised concerns around the impacts that calcium supplements could have on cognitive health, particularly dementia. Results from our study provides reassurance to patients and clinicians regarding the safety of calcium supplements in the context of dementia risk for older women," Ms Ghasemifard said.
ECU Senior Research Fellow Dr Marc Sim noted that when the analysis was adjusted for supplement compliance, a range of lifestyle factors, including dietary calcium intake and genetic risk, the results remained unchanged.
"Previous research suggesting potential links between calcium supplement use and the risk for dementia was purely observational in nature. Our research, in comparison, consisted of a post-hoc analysis from a 5-year double-blind, placebo controlled randomised clinical trial on calcium supplements to prevent fracture. Whilst our study is still epidemiology, its design does reduce the likelihood of unmeasured confounding"
"Some 730 older women were given calcium supplements over five years, and a further 730 were given placebo. This study design offers more accurate data on dosage and duration, and we had a long follow-up period of 14.5 years, which strengthens our results," Dr Sim said.
While these findings may alleviate concerns regarding calcium supplementation and all-cause dementia risk in older women, particularly after the age of 80 years, Professor Simon Laws, Director of ECU’s Centre for Precision Health, said further research was required.
"Whether this extrapolates to other demographics, such as men or even women commencing supplementation earlier in life, remains unknown. To confirm the current findings, particularly regarding brain health, and to address these population gaps, future clinical trials of calcium supplements, with or without vitamin D, would need to be undertaken. These should include specific and robust assessments of brain health as the primary outcome measures."
Curtin University's Professor Blossom Stephan, Director of the Dementia Centre of Excellence and a Dementia Australia Honorary Medical Advisor said the research highlighted a very important finding that provides reassurance to clinicians and patients about the long-term safety of calcium supplementation.
"Given calcium's critical role in multiple physiological functions, including bone health, these results provide reassurance that long-term calcium supplementation did not increase dementia risk in older women," she said.
