People who suffer from diabetes need to worry much more about their blood sugar level and what they eat. A concerning new study is revealing that those with diabetes have a higher risk of developing Alzheimer’s disease. The findings suggest that maintaining good control over diabetes or preventing it altogether could be crucial in reducing the risk of Alzheimer’s.
The study, which will be presented at the Discover BMB meeting in San Antonio, adds to the growing body of evidence linking Type 2 diabetes and Alzheimer’s disease, with some scientists even referring to Alzheimer’s as “Type 3 diabetes.”
“We think that diabetes and Alzheimer’s disease are strongly linked, and by taking preventative or amelioration measures for diabetes, we can prevent or at least significantly slow down the progression of the symptoms of dementia in Alzheimer’s disease,” says study lead author Narendra Kumar, an associate professor at Texas A&M University in College Station, in a media release.
Diabetes and Alzheimer’s are two of the most rapidly growing health concerns worldwide. Diabetes, which affects an estimated one in 10 American adults, alters the body’s ability to convert food into energy. Alzheimer’s, on the other hand, is a form of dementia that causes a progressive decline in memory and thinking skills and ranks among the top 10 leading causes of death in the United States.
To understand how diet could influence the development of Alzheimer’s in people with diabetes, researchers focused on a specific protein in the gut called Jak3. They discovered that a high-fat diet suppresses the expression of this protein, and mice lacking Jak3 experienced a cascade of inflammation that started in the intestine, moved through the liver, and ultimately reached the brain. As a result, the mice exhibited signs of Alzheimer’s-like symptoms, including an overexpression of mouse beta-amyloid and hyperphosphorylated tau, as well as evidence of cognitive impairment.
“Liver being the metabolizer for everything we eat, we think that the path from gut to the brain goes through liver,” explains Kumar.
Kumar’s lab has been studying the functions of Jak3 for a long time, and they now know that the impact of food on the changes in Jak3 expression leads to a condition called leaky gut. This, in turn, results in low-grade chronic inflammation, diabetes, decreased ability of the brain to clear its toxic substances, and dementia-like symptoms seen in Alzheimer’s.
Leaky gut, also known as increased intestinal permeability, occurs when the tight junctions between the cells lining the intestinal wall become compromised, allowing bacteria, toxins, and partially digested food particles to “leak” into the bloodstream. This can trigger an immune response and lead to chronic inflammation throughout the body, which has been linked to various health problems, including diabetes and Alzheimer’s.
The findings of this study offer hope for those at risk of developing Alzheimer’s due to diabetes. Kumar emphasizes that it may be possible to halt this inflammatory pathway by adopting a healthy diet and getting blood sugar under control as early as possible. This is particularly important for the estimated 98 million U.S. adults with prediabetes, a condition characterized by higher-than-normal blood sugar levels that are not yet high enough to be diagnosed as diabetes.
By making lifestyle changes to reverse prediabetes and prevent the progression to Type 2 diabetes, individuals could potentially reduce their risk of developing Alzheimer’s.
