Table of ContentsView AllTable of ContentsThe Connection Between Alzheimer’s and DiabetesType 3 Diabetes SymptomsCausesDiagnosisTreatmentPrevention
Table of ContentsView All
View All
Table of Contents
The Connection Between Alzheimer’s and Diabetes
Type 3 Diabetes Symptoms
Causes
Diagnosis
Treatment
Prevention
A Diabetic Testing Her Blood Sugar/ ballyscanlon/Digital Vision/ Getty Images.
According to the American Diabetes Association (ADA), aside from advanced age having diabetes or prediabetes is the second biggest risk factor for Alzheimer’s disease. Although a small amount of research found an increased risk of dementia with type 1 diabetes, the vast majority of studies have concluded that this link between diabetes and Alzheimer’s is specific totype 2 diabetes.
However, classifying Alzheimer’s as type 3 diabetes is controversial, and many in the medical community are unwilling to recognize type 3 diabetes as a medical diagnosis until more research is done.
Note that type 3 diabetes is not the same as type 3c diabetes mellitus (also called T3cDM or pancreatogenic diabetes), a secondary condition that may arise as a result of other pancreatic diseases.
Studies show the risk of developing Alzheimer’s disease among people with diabetes is 65% higher than that of those without diabetes. With such a strong link, research has focused on explaining the connection between the two diseases.
Type 2 diabetes occurs when insulin becomes less sensitive to glucose (sugar) and therefore less efficient at removing it from the bloodstream, allowing it to build up rather than being taken into the cells to be used for energy.
In Alzheimer’s disease, it appears a similar problem ofinsulin resistanceoccurs, but rather than affecting the body as a whole, the effects are localized in the brain.
In studies of people’s brains after death, researchers have noted the brains of those who had Alzheimer’s disease but did not have type 1 or type 2 diabetes showed many of the same abnormalities as the brains of those with diabetes, including low levels of insulin in the brain. It was this finding that led to the theory that Alzheimer’s is a brain-specific type of diabetes—“type 3 diabetes.”
In diabetes, if a person’s blood sugars become too high or too low, the body sends obvious signs of the problem: behavior changes, confusion, seizures, etc. In Alzheimer’s disease, however, rather than those acute signals, the brain’s function and structure decline gradually over time.
When a group of researchers reviewed the collections of studies available on Alzheimer’s disease and brain function, they noted that a common finding in Alzheimer’s disease was the deterioration of the brain’s ability to use and metabolize glucose. They compared that decline with cognitive ability and noted that the decline in glucose processing coincided with, or even preceded, the cognitive declines ofmemory impairment,word-finding difficulty,behavior changes, and more.
Furthermore, scientists determined that as insulin functioning in the brain worsens, not only does cognitive ability decline, the size and structure of the brain also deteriorate—all of which normally occur as Alzheimer’s disease progresses.
The term “type 3 diabetes” is used, therefore, in two circumstances: to describe an actual type of diabetes that only affects the brain and to describe the progression of type 2 diabetes to Alzheimer’s disease.
The symptoms of type 3 diabetes are essentially the same as the symptoms of early dementia, which, according to the Alzheimer’s Association, include:
For decades, researchers have attempted to determine the specific cause of Alzheimer’s disease. Some research suggests that while diabetes likely exacerbates and contributes to the development of Alzheimer’s disease, it is probably not the sole cause of it.
What Is Alzheimer’s Disease?
Risk Factors
The primary risk factor for developing type 3 diabetes is having type 2 diabetes. The risk factors for developing type 2 diabetes include:
Causes and Risk Factors of Type 2 Diabetes
Althought there’s no dedicated test for type 3 diabetes, clinicians will typically look for signs of Alzheimer’s and signs of diabetes.
To diagnose Alzheimer’s, a doctor will:
If you have symptoms of type 2 diabetes, your physician may also request that you do a fasting or random glucose test and a hemoglobin A1C (Hb A1C) test to see how well your blood sugar is being controlled.
What Is an A1C Test?
If you have been diagnosed with both type 2 diabetes and Alzheimer’s, your physician may recommend a diabetes treatment protocol to help get your blood sugar levels under control.
Standard treatment for type 2 diabetes includes:
There is potential that diabetes medications such as metformin and glucagon-like peptides may be helpful in preventing the progression of Alzheimer’s.In animal and human studies, these medications have shown evidence of improving insulin sensitivity that may protect against the structural abnormalities that develop in Alzheimer’s disease, improve the brain’s ability to metabolize glucose, and demonstrate an improvement in cognitive functioning in some cases.
Type 2 Diabetes Medication and Treatment
Pharmaceutical treatment for Alzheimer’s has proven elusive.While there are several prescription medications designed to treat Alzheimer’s symptoms, their effectiveness remains in question.
Behavioral symptoms such as depression, common in early Alzheimer’s, are typically treated with selective serotonin reuptake inhibitors (SSRIs) such as Prozac (fluoxetine).
Alzheimer’s medications are generally trialed first for eight weeks, then reviewed to determine if there’s any benefit.
How Alzheimer’s Disease Is Treated
There’s a good deal of crossover between measures that can help to prevent both diabetes and Alzheimer’s, such as following ahealthy dietand increasing physical activity.
Toreduce the riskof developing Alzheimer’s disease specifically, follow these four pillars:
Numerous studies have revealed how lifestyle changes can improve glucose control in people with type 2 diabetes. In addition to the four pillars above, other measures that can help stave off diabetes include:
A Word From Verywell
If you have diabetes and are concerned about your risk of developing Alzheimer’s disease as a result, discuss your concerns with your physician. They may be able to fine tune your treatment and management strategies to help shore up your defense against Alzheimer’s.
12 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Arvanitakis Z, Wilson RS, Bienias JL, Evans DA, Bennett DA.Diabetes mellitus and risk of Alzheimer disease and decline in cognitive function.Arch Neurol. 2004;61(5):661-6. doi:10.1001/archneur.61.5.661Kandimalla R, Thirumala V, Reddy PH.Is Alzheimer’s disease a Type 3 Diabetes? A critical appraisal.Biochim Biophys Acta Mol Basis Dis. 2017;1863(5):1078-1089. doi:10.1016/j.bbadis.2016.08.018Calsolaro V, Edison P.Alterations in glucose metabolism in alzheimer’s disease.Recent Pat Endocr Metab Immune Drug Discov. 2016;10(1):31-39. doi:10.2174/1872214810666160615102809Alzheimer’s Association.10 early signs and symptoms of Alzheimer’s.Moheet A, Mangia S, Seaquist ER.Impact of diabetes on cognitive function and brain structure.Ann N Y Acad Sci. 2015;1353:60-71. doi:10.1111/nyas.12807Wilmot E, Idris I.Early onset type 2 diabetes: risk factors, clinical impact and management.Therapeutic Advances in Chronic Disease.2014;5(6):234–244. doi:10.1177/2040622314548679Alexander, M. Larson, EB. UpToDate:Patient education: Dementia (including Alzheimer disease) (Beyond the Basics).Femminella GD, Bencivenga L, Petraglia L, et al.Antidiabetic drugs in alzheimer’s disease: mechanisms of action and future perspectives.J Diabetes Res.2017;2017:7420796. doi:10.1155/2017/7420796Khalsa DS, Perry G.The four pillars of alzheimer’s prevention.Cerebrum. 2017;2017:cer-03-17.Hamman RF, Wing RR, Edelstein SL, et al.Effect of weight loss with lifestyle intervention on risk of diabetes.Diabetes Care. 2006;29(9):2102-2107. doi:10.2337/dc06-0560National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes.Knutson KL.Impact of sleep and sleep loss on glucose homeostasis and appetite regulation.Sleep Med Clin. 2007;2(2):187-197. doi:10.1016/j.jsmc.2007.03.004Additional ReadingAlzheimer’s Association.Diabetes and cognitive decline.Craft S, Baker L, Montine TJ, et al.Intranasal insulin therapy for Alzheimer disease and amnestic mild cognitive impairment.Arch Neurol.2012;69(1):29-38. doi:10.1001/archneurol.2011.233De la Monte S, Wands JR.Alzheimer’s disease is type 3 diabetes–evidence reviewed.J Diabetes Sci Technol. 2008 November; 2(6): 1101–1113. doi:10.1177/193229680800200619Kroner Z.The relationship between Alzheimer’s disease and diabetes: Type 3 diabetes?Altern Med Review. 2009 Dec;14(4):373-9.
12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Arvanitakis Z, Wilson RS, Bienias JL, Evans DA, Bennett DA.Diabetes mellitus and risk of Alzheimer disease and decline in cognitive function.Arch Neurol. 2004;61(5):661-6. doi:10.1001/archneur.61.5.661Kandimalla R, Thirumala V, Reddy PH.Is Alzheimer’s disease a Type 3 Diabetes? A critical appraisal.Biochim Biophys Acta Mol Basis Dis. 2017;1863(5):1078-1089. doi:10.1016/j.bbadis.2016.08.018Calsolaro V, Edison P.Alterations in glucose metabolism in alzheimer’s disease.Recent Pat Endocr Metab Immune Drug Discov. 2016;10(1):31-39. doi:10.2174/1872214810666160615102809Alzheimer’s Association.10 early signs and symptoms of Alzheimer’s.Moheet A, Mangia S, Seaquist ER.Impact of diabetes on cognitive function and brain structure.Ann N Y Acad Sci. 2015;1353:60-71. doi:10.1111/nyas.12807Wilmot E, Idris I.Early onset type 2 diabetes: risk factors, clinical impact and management.Therapeutic Advances in Chronic Disease.2014;5(6):234–244. doi:10.1177/2040622314548679Alexander, M. Larson, EB. UpToDate:Patient education: Dementia (including Alzheimer disease) (Beyond the Basics).Femminella GD, Bencivenga L, Petraglia L, et al.Antidiabetic drugs in alzheimer’s disease: mechanisms of action and future perspectives.J Diabetes Res.2017;2017:7420796. doi:10.1155/2017/7420796Khalsa DS, Perry G.The four pillars of alzheimer’s prevention.Cerebrum. 2017;2017:cer-03-17.Hamman RF, Wing RR, Edelstein SL, et al.Effect of weight loss with lifestyle intervention on risk of diabetes.Diabetes Care. 2006;29(9):2102-2107. doi:10.2337/dc06-0560National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes.Knutson KL.Impact of sleep and sleep loss on glucose homeostasis and appetite regulation.Sleep Med Clin. 2007;2(2):187-197. doi:10.1016/j.jsmc.2007.03.004Additional ReadingAlzheimer’s Association.Diabetes and cognitive decline.Craft S, Baker L, Montine TJ, et al.Intranasal insulin therapy for Alzheimer disease and amnestic mild cognitive impairment.Arch Neurol.2012;69(1):29-38. doi:10.1001/archneurol.2011.233De la Monte S, Wands JR.Alzheimer’s disease is type 3 diabetes–evidence reviewed.J Diabetes Sci Technol. 2008 November; 2(6): 1101–1113. doi:10.1177/193229680800200619Kroner Z.The relationship between Alzheimer’s disease and diabetes: Type 3 diabetes?Altern Med Review. 2009 Dec;14(4):373-9.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Arvanitakis Z, Wilson RS, Bienias JL, Evans DA, Bennett DA.Diabetes mellitus and risk of Alzheimer disease and decline in cognitive function.Arch Neurol. 2004;61(5):661-6. doi:10.1001/archneur.61.5.661Kandimalla R, Thirumala V, Reddy PH.Is Alzheimer’s disease a Type 3 Diabetes? A critical appraisal.Biochim Biophys Acta Mol Basis Dis. 2017;1863(5):1078-1089. doi:10.1016/j.bbadis.2016.08.018Calsolaro V, Edison P.Alterations in glucose metabolism in alzheimer’s disease.Recent Pat Endocr Metab Immune Drug Discov. 2016;10(1):31-39. doi:10.2174/1872214810666160615102809Alzheimer’s Association.10 early signs and symptoms of Alzheimer’s.Moheet A, Mangia S, Seaquist ER.Impact of diabetes on cognitive function and brain structure.Ann N Y Acad Sci. 2015;1353:60-71. doi:10.1111/nyas.12807Wilmot E, Idris I.Early onset type 2 diabetes: risk factors, clinical impact and management.Therapeutic Advances in Chronic Disease.2014;5(6):234–244. doi:10.1177/2040622314548679Alexander, M. Larson, EB. UpToDate:Patient education: Dementia (including Alzheimer disease) (Beyond the Basics).Femminella GD, Bencivenga L, Petraglia L, et al.Antidiabetic drugs in alzheimer’s disease: mechanisms of action and future perspectives.J Diabetes Res.2017;2017:7420796. doi:10.1155/2017/7420796Khalsa DS, Perry G.The four pillars of alzheimer’s prevention.Cerebrum. 2017;2017:cer-03-17.Hamman RF, Wing RR, Edelstein SL, et al.Effect of weight loss with lifestyle intervention on risk of diabetes.Diabetes Care. 2006;29(9):2102-2107. doi:10.2337/dc06-0560National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes.Knutson KL.Impact of sleep and sleep loss on glucose homeostasis and appetite regulation.Sleep Med Clin. 2007;2(2):187-197. doi:10.1016/j.jsmc.2007.03.004
Arvanitakis Z, Wilson RS, Bienias JL, Evans DA, Bennett DA.Diabetes mellitus and risk of Alzheimer disease and decline in cognitive function.Arch Neurol. 2004;61(5):661-6. doi:10.1001/archneur.61.5.661
Kandimalla R, Thirumala V, Reddy PH.Is Alzheimer’s disease a Type 3 Diabetes? A critical appraisal.Biochim Biophys Acta Mol Basis Dis. 2017;1863(5):1078-1089. doi:10.1016/j.bbadis.2016.08.018
Calsolaro V, Edison P.Alterations in glucose metabolism in alzheimer’s disease.Recent Pat Endocr Metab Immune Drug Discov. 2016;10(1):31-39. doi:10.2174/1872214810666160615102809
Alzheimer’s Association.10 early signs and symptoms of Alzheimer’s.
Moheet A, Mangia S, Seaquist ER.Impact of diabetes on cognitive function and brain structure.Ann N Y Acad Sci. 2015;1353:60-71. doi:10.1111/nyas.12807
Wilmot E, Idris I.Early onset type 2 diabetes: risk factors, clinical impact and management.Therapeutic Advances in Chronic Disease.2014;5(6):234–244. doi:10.1177/2040622314548679
Alexander, M. Larson, EB. UpToDate:Patient education: Dementia (including Alzheimer disease) (Beyond the Basics).
Femminella GD, Bencivenga L, Petraglia L, et al.Antidiabetic drugs in alzheimer’s disease: mechanisms of action and future perspectives.J Diabetes Res.2017;2017:7420796. doi:10.1155/2017/7420796
Khalsa DS, Perry G.The four pillars of alzheimer’s prevention.Cerebrum. 2017;2017:cer-03-17.
Hamman RF, Wing RR, Edelstein SL, et al.Effect of weight loss with lifestyle intervention on risk of diabetes.Diabetes Care. 2006;29(9):2102-2107. doi:10.2337/dc06-0560
National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes.
Knutson KL.Impact of sleep and sleep loss on glucose homeostasis and appetite regulation.Sleep Med Clin. 2007;2(2):187-197. doi:10.1016/j.jsmc.2007.03.004
Alzheimer’s Association.Diabetes and cognitive decline.Craft S, Baker L, Montine TJ, et al.Intranasal insulin therapy for Alzheimer disease and amnestic mild cognitive impairment.Arch Neurol.2012;69(1):29-38. doi:10.1001/archneurol.2011.233De la Monte S, Wands JR.Alzheimer’s disease is type 3 diabetes–evidence reviewed.J Diabetes Sci Technol. 2008 November; 2(6): 1101–1113. doi:10.1177/193229680800200619Kroner Z.The relationship between Alzheimer’s disease and diabetes: Type 3 diabetes?Altern Med Review. 2009 Dec;14(4):373-9.
Alzheimer’s Association.Diabetes and cognitive decline.
Craft S, Baker L, Montine TJ, et al.Intranasal insulin therapy for Alzheimer disease and amnestic mild cognitive impairment.Arch Neurol.2012;69(1):29-38. doi:10.1001/archneurol.2011.233
De la Monte S, Wands JR.Alzheimer’s disease is type 3 diabetes–evidence reviewed.J Diabetes Sci Technol. 2008 November; 2(6): 1101–1113. doi:10.1177/193229680800200619
Kroner Z.The relationship between Alzheimer’s disease and diabetes: Type 3 diabetes?Altern Med Review. 2009 Dec;14(4):373-9.
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