Older adults who take calcium to protect their bones can rest easier. New research from Edith Cowan University, Curtin University and the University of Western Australia found no evidence that calcium supplements increase the long-term risk of dementia, a finding that helps dispel earlier concerns about their potential effects on brain health.
Calcium is widely recommended to prevent osteoporosis, especially in women over 70, but some past studies hinted at possible cognitive risks. The new research, published in The Lancet, drew on data from a five-year clinical trial that followed 1,460 women for more than 14 years. The study found no increase in dementia risk among women who took calcium supplements, even after accounting for diet, lifestyle and genetics.
“Calcium supplements are often recommended to prevent or manage osteoporosis,” said Negar Ghasemifard, a PhD student at Edith Cowan University. “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.”
Senior researcher Dr. Marc Sim noted that earlier findings linking calcium and dementia were based on observational data.
“Previous research suggesting potential links between calcium supplement use and the risk for dementia was purely observational in nature,” he said. “Our research, in comparison, consisted of a post-hoc analysis from a five-year double-blind, placebo controlled randomized clinical trial on calcium supplements to prevent fracture.”
That design, he added, makes the results far more reliable: “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.”
While these findings apply specifically to older women, the researchers said more studies are needed to see whether they hold true for other groups. Professor Simon Laws, director of ECU’s Centre for Precision Health, explained that “whether this extrapolates to other demographics, such as men or even women commencing supplementation earlier in life, remains unknown.”
For now, experts say the results should reassure older women who rely on calcium to protect their bones. Professor Blossom Stephan, Dementia Australia honorary medical advisor, said the findings highlight “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.
This research was supported by the National Health and Medical Research Council of Australia.