Calcium Supplements Increase Dementia Risk in Older Women Who Had Stroke

Highlights

• Osteoporosis is a common condition in older women that occurs due to the loss of bone mineral density
• Women are prescribed calcium supplements to maintain their bone health
• But a study claims that calcium supplements may increase dementia risk in older women who had a stroke

Calcium supplements may be linked to increased risk of dementia in older women who have a history of stroke or have other signs of cerebrovascular disease, suggests a new study. Stroke is a cerebrovascular disease that hinders the flow of blood to the brain and increases the risk of developing dementia.

Role of Calcium

Calcium is an essential micronutrient which is needed for optimal bone health. The body does not produce calcium, so the body relies on the diet to meet the calcium requirement. Heart, muscles, and nerves also need calcium to function efficiently. Calcium is also known to play a key role in protecting against cancer, diabetes, and high blood pressure.

The recommended levels of calcium are not met, the bone mineral density may reduce. Women over the age of 50 years are more likely to suffer from osteoporosis when their diet lacks calcium. Osteoporosis means "porous bone" which is a bone disease. This condition usually occurs when the body loses the bone density. The bone becomes weak and can easily break from a fall. Globally, 200 million women suffer from osteoporosis. About 8.9 million fractures are caused due to osteoporosis every year.

Calcium Supplements and Risk of Dementia

The recommended dietary allowance of calcium for women over the age of 50 is 1000 to 1,200mg per day. Post-menopausal women are prescribed calcium supplements to lower their risk of developing osteoporosis. But the safety and efficacy of calcium supplements are being called into question. So researchers from the University of Gothenburg in Sweden conducted a study on the use of supplements and their effect on health.

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Seven hundred dementia-free women between the ages of 70 and 92 participated in the study. The participants were followed for five years. A variety of tests were taken at the beginning and at the end of the study. Tests on memory and thinking skills were also taken. CT scan was performed on 447 participants at the beginning of the study.

The researchers looked at the use of calcium supplements in the participants to analyzed if they developed dementia during the course of the study. About 98 participants were taking calcium supplements at the start of the study. Fifty-four women had experienced a stroke before the study. During the course of study, 54 more women had strokes, and 59 women developed dementia.

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About 71% of the women who underwent CT scans had lesions in their brains’ white matter, which is a marker for the cerebrovascular disease.

The Findings of the Study

• Women who were taking calcium supplements were twice as likely to develop dementia than women who did not take supplements.
• Further analysis of the data showed that the increased dementia risk was only among women with the cerebrovascular disease.
• The risk of developing dementia was seven times higher in women with a history of stroke who had taken calcium supplements than those who did not take the supplements.
• Women who had lesions in their brain’s white matter and also took supplements were three times likely to develop dementia than women who had lesions but did not take supplements.
• Women without a history of stroke or without white matter lesions had no risk of dementia when taking calcium supplements.

Out of the 98 women who had taken calcium supplements, 14 developed dementia. Six out of 15 women with a history of stroke who took the supplements developed dementia compared to 12 out of 93 women with a history of stroke who did not take supplements.

Eighteen out of 83 women without a history of stroke who took supplements developed dementia compared to 33 out of 509 women who did not take supplements.

"It is important to note that our study is observational, so we cannot assume that calcium supplements cause dementia," said study author Silke Kern, MD, PhD with the University of Gothenburg in Sweden.

The limitation of the study is that it was small and results cannot be generalized to the overall population. Further studies may be needed to confirm the findings. The research is published in Neurology, the medical journal of the American Academy of Neurology.

Other Risks of Calcium Supplements

Earlier studies have shown that calcium supplements may increase the possibility of heart disease. However, more research is needed to prove the effect of calcium supplements and risk of heart disease. Calcium supplements have also been linked to prostate cancer risk. But a recent study showed no risk of prostate cancer associated with high intake of dietary calcium or supplemental calcium intake. However, it is important to avoid excessive intake of calcium and consult with a general physician or a dietitian to determine the recommended intake of calcium.

Calcium and Diet

Calcium from diet appears to be safe and protective against cerebrovascular disease.

Calcium is found in a variety of foods such as

• Dairy products - milk, yogurt, cheese
• Fish - sardines, salmon, black cod
• Soy products - tofu
• Vegetables - kale, broccoli, brussels sprouts, celery
• Fortified cereal

References:

1. Facts and Statistics - (https://www.iofbonehealth.org/facts-statistics)
2. Calcium and calcium supplements: Achieving the right balance - (http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/calcium-supplements/art-20047097?pg=1)
3. Calcium and Bone Health - (http://www.helpguide.org/articles/healthy-eating/calcium-and-your-bones.htm)

Source-Medindia