The Relationship Between Diabetes and Dementia

How can a chronic condition originating from the pancreas double your risk of developing Alzheimer’s or dementia?

According to the Centers for Disease Control and Prevention, more than 30 million Americans are currently living with diabetes. It occurs when cells in the pancreas are unable to produce enough insulin — a hormone that tells the body to import the sugar circulating in the blood into the body. Because sugar is the main source of fuel for the brain, diabetes symptoms can cause fatigue and cognitive impairment.


When the brain doesn’t get enough energy, it alters its metabolism and leads to cellular damage. These factors may make it more likely that someone with diabetes develops Alzheimer’s disease, or another form of dementia. Additionally, there are many shared risk factors between these two diseases that further explain their close relationship.


Here’s what diabetes and dementia have in common


One of the largest known genetic risk factors for developing Alzheimer’s in certain populations, ApoE4, is also a major risk factor for developing diabetes. This gene encodes a protein that carries cholesterol, increasing blood pressure. While this protein is too large to enter the brain, it is produced by cells called astrocytes and may trigger the release of amyloid plaques.


Next, high levels of blood sugar which can contribute to the onset of diabetes are also a risk factor for the development of Alzheimer’s and other forms of dementia.



A 2013 study published in the New England Journal of Medicine found that any abnormal elevations in blood sugar — even in people without diabetes — increased the risk of developing dementia.


In addition, medications that bring blood glucose under control like metformin are also linked to a reduction in Alzheimer’s risk in people who already have diabetes.


Black Americans are at an elevated risk of developing diabetes and Alzheimer’s. Since the majority of medical research has been conducted on white individuals, studies are seeking to diversify their participants to better understand this risk factor. Meanwhile, poor socioeconomic status which is more common in African American communities is linked to diabetes risk.

Prevention strategies that work for both diseases


With so many shared risk factors between the two diseases, there is some good news. Many of the same strategies used to prevent diabetes also reduce the risk of developing Alzheimer’s or other forms of dementia.


A healthy Mediterranean-style diet leads to reductions in cholesterol and blood sugar. Importantly in the case of Alzheimer’s, it also means less cognitive impairment. This diet provides a great variety in terms of taste, consisting of:

  • Fruits, vegetables, and legumes

  • Nuts and seeds

  • Whole grains

  • Fish, seafood and olive oil

Regular exercise also reduces the risk of developing dementia and helps prevent diabetes. During exercise, there is a reduction in blood sugar levels as the body mobilizes it to fuel the muscles. Exercise also may increase the brain’s metabolic rate, staving off cellular damage.


A combination of healthy eating and exercise can jointly fight against diabetes and Alzheimer’s. As scientists look to better understand the relationship between these two diseases, they come closer to finding new treatments for both.





To learn about clinical trials of new medications that aim to modify the pathology of Alzheimer's disease, call Charter Research at 407-337-1000 (Orlando) or 352-775-1000 (The Villages).

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