As women age, they have to be sure to get enough calcium or their bones could suffer. Many doctors will prescribe calcium supplements to women at elevated risk for osteoporosis; risk factors can include a slight build or a close relative with the condition. But more calcium isn’t always better, it turns out: For women who have a history of stroke or trouble with blood flow to the brain, more calcium could raise their risk of dementia.
The five-year study, which was published by the American Academy of Neurology, tracked 700 women between the ages of 70 and 92 who had no signs of dementia. The researchers, led by Silke Kern, MD, PhD, at the University of Gothenburg in Sweden, initially found that women who were taking calcium supplements were twice as likely to develop dementia. But when Dr. Kern drilled down into the numbers, she discovered that only women who had a history of cerebrovascular disease—an aneurysm, for example, or a stroke—experienced an increased risk. Dr. Kern also discovered the risk was much higher for this group—they were seven times more likely to develop dementia if they also were on calcium supplements.
Going a step further, Dr. Kern next looked at the influence of calcium supplements on dementia risk in women who had signs of cerebrovascular damage in their brains—white matter lesions. (Some mild strokes and other types of cerebrovascular disease can go undiagnosed.) Women with white matter lesions and who took calcium supplements had three times the risk of dementia compared to women with the lesions who didn’t take the bone-supporting supplements. Watch for these signs of a stroke that women are likely to ignore.
The good news? Women with no history of cerebrovascular disease had no increased dementia risk from calcium pills. Dr. Kern was also quick to point out to Science Daily that the study only established a link between the supplements, cerebrovascular disease, and dementia risk; it doesn’t prove that taking calcium can actually cause dementia. But if you have a history of blood flow issues or stroke, you may want to discuss these findings with your doctor. She also notes that getting calcium from food doesn’t seem to be linked to any risk increase. You can also eat a diet that minimizes your risk of stroke: These are the foods that help protect you.