A new study found that middle-aged adults with type 2 diabetes are twice at risk to developing dementia as it shrinks the brain and important parts of it responsible for short-term and long-term memory.

Researchers from the Mayo Clinic, led by Rosebud O. Roberts, M.D., found that midlife onset of diabetes shrink the brain and affect the cognitive functions of it, thus leading to dementia later in their lives.

They recruited 1,437 participants with an average age of 80. The participants were evaluated by a nurse and were submitted to neuropsychological testing to check if they have normal cognitive functions, mild cognitive impairments, or have dementia. They also underwent MRI scanning, white matter hyperintensity volume, hippocampal volume, and whole brain volume to check for brain damage and determine the size of their brain and some parts of it.

Lastly, their medical records were reviewed to see if they had been diagnosed with type 2 diabetes and when it occurred.

After reviewing the results and records, they found that those who were diagnosed with diabetes between ages 40 to 64 had brains 2.9 percent smaller than those without diabetes. Their hippocampi were also smaller by four percent compared to those without diabetes.

They also found that participants who had diabetes during their midlife were 85 percent at risk of micro-strokes in the brain and twice as likely to have memory problems.

"When your hippocampus begins to shrink, you begin to lose your long-term memory and your ability to remember recent events," said Roberts, who also is a member of the American Academy of Neurology, to Healthday.

Also, "if you have type 2 diabetes, you have an increased risk of brain damage," Roberts added. "But if you control your diabetes well, it should reduce the damage that is being caused in your brain."

Further details of this study can be read in March 19 issue of Neurology.