Older women with both diabetes and naturally high oestrogen levels are 14 times more likely to develop dementia than women without diabetes, according to new research.
The study from the French National Institute of Health and Medical Research also found that women with high levels of oestrogen - but no diabetes - were at an increased risk of dementia, but at a much lower level than those with diabetes.
Researchers measured the level of blood oestrogen hormones in 5,644 post-menopausal women aged 65 years or older that didn't have dementia. Four years later, these women were assessed for dementia and common dementia risk factors including diabetes and high blood pressure. The study is published in the journal Neurology.
Comparing 132 women with dementia to 543 women without it, those with both very low and very high levels of natural oestrogen were twice as likely to develop the condition when compared to those with normal oestrogen levels. But in the 10 women with both diabetes and high oestrogen, this risk was amplified even further and was 14 times greater than for women with diabetes and normal hormone levels.
Dr Doug Brown, Director of Research and Development at Alzheimer's Society, says of the research findings:
'It is surprising to see that older women with both naturally high oestrogen levels and diabetes were so much more likely to develop dementia in this study. However, as this only applied to 10 women, we need to conduct much larger studies before reaching any conclusions.
'Although it's very difficult to do anything about lowering your oestrogen levels, we do know that people can take steps to reduce their chance of developing diabetes. Adopting a healthy diet and taking regular exercise might be the key to helping prevent both diabetes and dementia.'