Calcium pills ‘raise dementia risk for women stroke victims’

CALCIUM supplements could dramatically raise the risk of dementia in women who suffer a stroke, according to a study.

Scientists found that women who have had strokes were seven times more likely to develop dementia if they were taking calcium, which thousands use to combat brittle bones caused by osteoporosis after the menopause.

Those who had not had strokes but whose brains showed signs of damage – known as cerebrovascular disease – on scans were also three times more likely to have dementia than those not taking the supplements.

There was no association between calcium supplements and dementia in women with no evidence of cerebrovascular disease.

Lead scientist Dr Silke Kern, from the University of Gothenburg in Sweden, said: ‘Osteoporosis is a common problem in the elderly. Because calcium deficiency contributes to osteoporosis, daily calcium intake of 1000 to 1200mg is recommended (for those with the condition). Getting this recommended amount through diet alone can be difficult, so calcium supplements are widely used. Recently, however, the use of supplements and their effect on health has been questioned.’

She pointed out that the observational study did not show that dementia was triggered by calcium supplements.

For the research, published in the journal Neurology, scientists analysed 700 women aged between 70 and 92, who were all free from dementia at the start. Of the total, 98 were taking calcium supplements and 54 had already experienced a stroke.

The women’s memory and thinking skills were tested and their progress was followed for five years. Brain scans were also carried out on 447 of the participants. During the course of the study, 54 more women had strokes and 59 developed dementia. Among the women who had CT scans, 71 per cent had lesions on the white matter of their brains, which is a marker for cerebrovascular disease.

Researchers found that, overall, women who took calcium supplements were twice as likely to develop dementia as those who did not. On deeper analysis they realised the increased risk was limited to women with a history of cerebrovascular disease, especially stroke.

Dr Kern stressed that the study was small and more work was needed to confirm the findings.

Previous research has suggested that calcium supplements affect the body differently to calcium from food – such as milk, cheese and green leafy vegetables – and may be linked to a higher risk of artery disease.

Dr Doug Brown, of the Alzheimer’s Society charity, said: ‘While this research does not show a direct link between calcium supplements and increased dementia risk, it does warrant further investigation. People should not worry about eating and drinking calcium as part of a normal, healthy balanced diet.’

‘Supplements are widely used’