RAISED blood sugar is linked to dementia even in people without diabetes, a study has shown.

Scientists found a close association between glucose levels and dementia risk in a group of 2000 older patients aged 65 and over.

Even in apparently healthy participants, a blood sugar level increase from 100 to 115 milligrams per decilitre (mg/dl) raised the risk of dementia by 18%.

In those with diabetes, whose blood sugar tends to be higher than average, the risk was higher. A diabetes patient with a glucose reading of 190 mg/dl was 40% more at risk than one with a level of 160 mg/dl.

Lead researcher Paul Crane, from the University of Washington in Seattle, US, said: "The most interesting finding was that every incrementally higher glucose level was associated with a higher risk of dementia in people who did not have diabetes. There was no threshold value for lower glucose values where risk levelled off."

Blood sugar levels depend on individual metabolism as well as what you eat, the scientists pointed out.

High blood pressure, heart problems, high cholesterol and diabetes are all thought to cause or increase damage to the vascular system and increase the risk of a patient developing vascular dementia. Diabetes has also been linked to Alzheimer's disease.

The latest findings appear in the New England Journal Of Medicine. More research is planned to uncover what underlies the link between blood sugar and dementia.