Diabetes may increase your risk of Alzheimer’s. But blood sugar control, exercise and a healthy diet may help.
There’s a lot of research suggesting a connection between diabetes and Alzheimer’s — though those connections aren’t yet fully understood. Not all studies confirm the connection, but many do suggest that people with diabetes, especially type 2 diabetes, are at higher risk of eventually developing Alzheimer’s dementia or other dementias.
Research is still unclear on whether taking steps to prevent or control diabetes may help reduce your risk of cognitive decline.
New research finds how early you develop diabetes, might determine your risk for developing dementia.
Understanding the connection
Diabetes can cause several complications, such as damage to your blood vessels. Diabetes is considered a risk factor for vascular dementia. This type of dementia occurs due to brain damage that is often caused by reduced or blocked blood flow to your brain.
Many people with diabetes have brain changes that are hallmarks of both Alzheimer’s disease and vascular dementia. Some researchers think that each condition fuels the damage caused by the other.
Ongoing research is aimed at trying to better understand the link between Alzheimer’s and diabetes. That link may occur as a result of the complex ways that type 2 diabetes affects the ability of the brain and other body tissues to use sugar (glucose) and respond to insulin.
Diabetes may also increase the risk of developing mild cognitive impairment (MCI), a condition in which people experience more thinking (cognitive) and memory problems than are usually present in normal aging. Some research indicates that diabetes may increase the risk of MCI worsening to dementia. Mild cognitive impairment may precede or accompany Alzheimer’s disease and other types of dementia.
As researchers examine the connections between diabetes and Alzheimer’s, they’re also studying potential ways to prevent or treat both diseases. But a recent trial of intranasal insulin showed no cognitive benefit.
Reducing your risk
Working with your health care team to prevent diabetes or manage your diabetes has been shown to be an effective strategy to avoid or reduce complications. Diabetes prevention or effective diabetes management may also help prevent Alzheimer’s disease and other dementias.
Preventing diabetes or managing it successfully may help you avoid other complications, such as:
- Heart disease
- Eye damage
- Kidney disease
- Nerve damage, which may cause pain in your feet or hands (diabetic neuropathy)
- Digestive problems (gastroparesis)
- Bone and joint problems
Steps to prevent or manage diabetes and avoid potential complications include:
- Follow your health care team’s recommendations about the most appropriate plan for monitoring your blood glucose, cholesterol level and blood pressure.
- Eat healthy foods, including fruits, vegetables, whole grains, lean meats, and low-fat milk and cheese.
- If you’re overweight, eat a healthy diet and exercise to lose weight. Obesity can lead to diabetes and other health problems.
- Don’t smoke.
- Aim to exercise for at least 30 minutes every day.
- Examine your feet daily for sores.
- Take any prescribed medications on schedule.
Evidence suggests that diet and activity changes that lead to weight loss are especially effective in reducing diabetes risk.
Even small steps can make a big difference. In a major clinical research study, participants with blood sugar levels slightly above normal (prediabetes) cut their risk of developing type 2 diabetes by more than 50 percent through exercise (30 minutes five days a week) and as little as a 5 to 7 percent loss in body weight. That weight loss translates to 10 to 14 pounds (4.5 to 6.4 kilograms) for a 200-pound (about 91-kilogram) person.
There are many reasons to avoid high blood sugar. Unmanaged blood sugar can lead to increased risk for heart disease, nerve damage, and diabetes. Despite the general awareness on the effects of diabetes, many are still unaware of their impact to the brain. Studies have shown that diabetes can not only increase the risk of dementia, but also hasten its development.
The Importance of Understanding the Link
Both diabetes and dementia have been on the rise recently. Approximately “one in three Canadians is living with diabetes or prediabetes. The majority of those with a diagnosis have Type 2 diabetes, where insulin produced in the body is unable to control blood sugar levels.
Diabetes can lead to cardiovascular disease. Therefore, an increased risk to cardiovascular diseases can directly increase the risk for dementia.
Much of the scientific research “on the diabetes-dementia link involves Type 2 diabetes, which studies show roughly doubles dementia risk and may cause it to develop a few years earlier.”
The Journal of the American Medical Association the age of onset of diabetes affects the risk of developing dementia. Of the 10,095 participants the trend indicated that the younger a person was at the onset of Type 2 diabetes the higher the risk of dementia.
How Does Diabetes Impact the Brain?
Scientists are still exploring the diabetes-dementia link. What is known are the effects that blood sugar levels can impact brain health.
Diabetes heightens the risk of cardiovascular problems “which may damage blood vessels in the brain.” This can also lead to strokes which can, in turn, result in dementia.
The treatment of diabetes can also lead to hypoglycemia. Hypoglycemic is a lower-than-normal blood glucose level. This can damage the hippocampus, the “memory center of the brain.”
Inflammation in the body caused by diabetes can also be a cause of damage to brain cells.
Scientists are also looking at a more direct causal link. They are investigating whether insulin resistance helps create the plaques of beta-amyloid protein which accumulate in the brains of those with Alzheimer’s.
Hope and Solution
Over the past 2 and a half decade, we have witnessed first-hand the devastating effects that a dementia diagnosis can have on families. It’s our hope to see this one day become a downward trend.
Should you need support today as you journey through the day-to-day issues of caring for someone living with symptoms of dementia, please don’t hesitate to reach out.
Is Alzheimer’s Type 3 diabetes?
It’s an accepted fact that people with Type 2 diabetes have a higher risk of Alzheimer’s disease. One reason may be reduced blood flow to the brain because of damaged blood vessels, Dr. Bu explains. “And, therefore, the supply of essential nutrients to the brain is also impaired.”
Dr. Bu has found genetics may also be to blame. A variant of the so-called Alzheimer’s gene, APOE4, seems to interfere with brain cells’ ability to use insulin, which may eventually cause the cells to starve and die. Unofficially, it’s called Type 3 diabetes. “What it refers [to] is that their brain’s insulin utilization or signaling is not functioning. Their risk of developing Alzheimer’s disease is about 10 to 15 times higher.”
Researchers wondered if it is diabetes of the brain, could insulin delivered in an intranasal mist help patients? The results of a phase 2 clinical trial have raised hope. “The outcome is very positive. The patient’s cognitive decline is slowed, if not improved.” The multi center research study will now expand into a broader phase 3 trial, with the backing of the National Institutes of Health.
More on the connection between Diabetes and Dementia
- Dilemma of the 3D’s- Dementia, Diabetes and Depression, from Sanford Blood Center
- 35-minute Pod Cast, 3-Ds, Depression, Diabetes and Dementia, from University of Washington, Continuing Nursing Education
- Heart Disease, Diabetes and Dementia: What are the Connections, presentation by Dr. Bruce Reed of University of California, Davis
- A Plague of Prosperity, presentation at Bringham Young University
- The Alzheimer’s Project: The Connection between Insulin and Alzheimer’s (HBO), Suzanne Craft, Ph.D, University of Washington, School of Medicine (2009)
- Vieira MN, et al. Connecting Alzheimer’s disease to diabetes: underlying mechanisms and potential therapeutic targets. Neuropharmacology. 2018;136:160.
- Rosales-Corral S, et al. Diabetes and Alzheimer disease, two overlapping pathologies with the same background: Oxidative stress. Oxidative Medicine and Cellular Longevity. 2015;2015:985845.
- Infante-Garcia C, et al. Long-term central pathology and cognitive impairment are exacerbated in a mixed model of Alzheimer’s disease and type 2 diabetes. Psychoneuroendocrinology. 2016;65:15.
- Larson EB, et al. Risk factors for cognitive decline and dementia. https://www.uptodate.com/contents/search. Accessed Feb. 27, 2019.
- National diabetes statistics report, 2017. Centers for Disease Control and Prevention. https://www.cdc.gov/features/diabetes-statistic-report/index.html. Accessed March 4, 2019.
- Biessels GJ, et al. Cognitive decline and dementia in diabetes mellitus: Mechanisms and clinical implications. Nature Reviews Endocrinology. 2018;14:591.
- 4 steps to manage your diabetes for life. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/diabetes/overview/managing-diabetes/4-steps. Accessed March 4, 2019.
- Dementia: Hope through research. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Dementia-Hope-Through-Research. Accessed Feb. 28, 2019.
- Østergaard SD, et al. Associations between potentially modifiable risk factors and Alzheimer disease: A Mendelian randomization study. PLOS Medicine. 2015;12:e1001841.
- Willette AA, et al. Association of insulin resistance with cerebral glucose uptake in late middle-aged adults at risk for Alzheimer disease. JAMA Neurology. 2015;72:1013.
- Ferreira LS, et al. Insulin resistance in Alzheimer’s disease. Frontiers in Neuroscience. 2018;12:830.
- De Felice FG, et al. Brain metabolic stress and neuroinflammation at the basis of cognitive impairment in Alzheimer’s disease. Frontiers in Aging Neuroscience. 2015;7:94.
- Keene CD, et al. Epidemiology, pathology, and pathogenesis of Alzheimer disease. https://www.uptodate.com/contents/search. Accessed Feb. 27, 2019.
- Wright, CB. Etiology, clinical manifestations, and diagnosis of vascular dementia. https://www.uptodate.com/contents/search. Accessed Feb. 28, 2019.
- Graff-Radford J (expert opinion). Mayo Clinic, Rochester, Minn. March 9, 2019.
- McDade EM, et al. Mild cognitive impairment: Prognosis and treatment. https://www.uptodate.com/contents/search. Accessed March 4, 2019.
- McDade EM, et al. Mild cognitive impairment: Epidemiology, pathology, and clinical assessment. https://www.uptodate.com/contents/search. Accessed March 4, 2019.
- Ferri FF. Diabetes mellitus. In: Ferri’s Clinical Advisor 2019. Philadelphia, Pa.: Elsevier; 2019. https://www.clinicalkey.com. Accessed March 4, 2019.
- Papadakis MA, et al., eds. Diabetes mellitus & hypoglycemia. In: Current Medical Diagnosis & Treatment 2019. 58th ed. New York, N.Y.: McGraw-Hill Education; 2019. https://accessmedicine.mhmedical.com. Accessed March 4, 2019.
- McCulloch DK, et al. Prevention of type 2 diabetes mellitus. https://www.uptodate.com/contents/search. Accessed March 4, 2019.
- Diabetes prevention program (DPP). National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/about-niddk/research-areas/diabetes/diabetes-prevention-program-dpp. Accessed March 4, 2019.