The food we eat is broken down in the digestive system into smaller components where it is absorbed into the bloodstream and then transported to cells to be used for energy. Carbohydrates from sources such as bread, vegetables and sweets are broken down into smaller compounds known as glucose. Glucose is transported into cells, including brain cells, with the help of a hormone called insulin. Researchers believe that the loss of glucose regulation typical in type 2 diabetes may increase the risk of Alzheimer’s disease.
What is Type 2 Diabetes (T2D)?
In T2D, insulin cannot work properly and as a result can no longer allow glucose entry into the cells. As a result, glucose remains in the blood at high concentrations, and will react with and damage blood vessels and organs such as the kidneys and eyes over time. High blood glucose levels also contribute to inflammation in the body. It is for this reason T2D is a risk factor for heart disease, kidney failure, and blindness.
Some signs of diabetes include frequent thirst and urination, unintended weight loss and poor wound healing. Since humans can’t feel high glucose levels they way they can feel back pain or a stomach ache, individuals may overlook these signs and remain undiagnosed for years. Aside from increasing the risk of heart, kidney and vision problems, uncontrolled diabetes may also increase the risk of Alzheimer’s disease.
What is Alzheimer’s disease (AD)?
AD is a form of dementia characterized by a decline in intellectual functioning. Advanced AD results in an inability to recognize loved ones or to perform activities of daily living such as eating and bathing. AD progresses quickly and is ultimately fatal.
The exact cause of AD is unknown but may be related to a variety of changes associated with aging. A diagnosis for AD requires the elimination of other conditions such as Parkinson’s disease, depression and vitamin deficiency which can contribute to symptoms. When AD is suspected, tools such as memory and cognitive tests may be used to confirm a diagnosis.
What is the Connection between T2D and AD?
T2D has long been recognized as a risk factor for AD since individuals with AD are more likely to have T2D than not. New research suggests that high blood glucose levels may contribute to the condition by damaging blood vessels in the brain and promoting inflammation.
The brain is a complex organ in which ‘information signals’ travel from one brain cell, or neuron, to another and from one area of the brain to another to help us perceive the world, store memories and form language. A healthy brain has a high number of neurons that have a high level of connection to other neurons.
Neurons rely heavily on glucose for energy (unlike other cells that can survive longer on fat and protein sources of energy) and may starve and die in cases of uncontrolled T2D. Additionally, insulin has been recognized as an important growth factor in the brain which promotes neuron growth and connectivity, meaning that an inability to respond to insulin may result in a loss of brain function and an increased risk for AD.
Minimizing the Risk
There are a variety of steps that can be taken to reduce the risk of T2D and AD:
- Exercise your body and mind. This can be as simple as parking further at the grocery store, taking the stairs instead of the elevator, doing crossword puzzles and maintaining an interesting social life.
- Eat well. A low-fat diet rich in vegetables, lean meat and whole grains can reduce the risk of both T2D and AD.
- See a doctor! A simple blood test can help determine if you have healthy blood glucose levels and if you are at risk of T2D.
Even if you have been diagnosed with T2D, these measures will help you control the condition.