A research group from Australia reported at the 15th World Congress of Endocrinology and 14th Joint European Congress of Endocrinology in Florence that older diabetic and pre-diabetic older adults with increasing blood sugar have 2.3 times more brain volume reduction than normal older adults and pre-diabetic older adults with stable blood sugar, meaning that diabetes and elevated blood sugar cause the brain to shrink faster. That’s why older adults with diabetes are always complaining about poor memory, losing things, and not being able to adapt to a new society. The study – which followed 312 participants from SydneyMemory and AgeingStudy in Sydney – compared MRI scans at the beginning and end of a 2-year period. The participants were older community-dwelling Australians, aged 70 to 90 years (mean age 78 years, 54% male), without dementia. At the start of the study, 41% had pre-diabetes and 13% had type 2 diabetes. At the end of the study, participants were divided into 4 groups: 1) normoglycemic seniors with stable glucose levels (102); 2) prediabetic seniors with stable glucose (120); 3) seniors with worsening glucose levels (57); and 4) those with type 2 diabetes from the beginning (33). MRI scans showed that the normal group lost an average of 18.4 cm3 of brain volume over a 2-year period. In contrast, the stable pre-diabetic group lost 1.4 times more brain volume (26.6 cm3). The third group (worsening glucose level group) and the fourth group (type 2 diabetes group) lost 2.3 times more brain volume relative to the stable group (41.7 cm3 and 42.3 cm3, respectively). We need to understand why the changes in cognitive ability and brain volume occurred. Is it just because of higher blood glucose? Is it that the brain suffers from glucose toxicity, as if the peripheral nerves were damaged? To what extent do other factors associated with diabetes cause a reduction in brain size and function, such as inflammation or fat levels in the blood? We also need to understand how we can prevent or stop the negative effects of diabetes on the brain. In short, we should be a little more tolerant of older diabetics and take better care of them. After all, they are sick people and their brain functions are shrinking faster than the average older person.