Dementia: Ask a neuroscientist
This Dementia Action Week, QBI neuroscientists answered some of the common questions about dementia. Here are the 5 most frequently asked questions.
Q: What is the difference between dementia and Alzheimer's?
A: Dementia refers to numerous brain disorders that impair learning, memory, thinking, and day-to-day activities. Alzheimer's disease is the most common form, accounting for ~60-80% of cases. Other types include frontotemporal dementia, vascular dementia, and Lewy body dementia.
Q: How does dementia affect the brain?
A: In people living with dementia, neurons in the brain become disconnected from each other and degenerate. This leads to symptoms due to progressive loss of the normal communication between the nerves that connect different parts of the brain.
Q: Is there a link between stroke and dementia?
A: Yes, stroke is a major cause of vascular dementia. The disruption of blood flow to the brain, typical of a stroke, damages and eventually kills brain cells. This leads to a progressive loss of function, and eventually dementia.
Q: What causes dementia?
A: Essentially, dementia is caused by damage or death of the nerve cells in our brain. Howevere, it is believed that the early loss of synaptic connections (the sites where nerve cells communicate with one another) is a major hallmark strongly associated with cognitive decline that precedes neuronal death. We know that the build-up of toxic proteins, genetic predisposition, inflammation, oxidative stress, and ageing contributes to the loss of synapses and cognitive deficits. However, the mechanisms by which these factors negatively affect the healthy functioning of synapses are not well understood.
Q: Are people who drink red wine and eat dark chocolate less likely to get dementia?
A: Several studies have shown that flavanol, which is found in dark chocolate, reduces the accumulation of amyloid beta plaques, a hallmark of Alzheimer’s disease (AD), via various mechanisms, including the enhancement of autophagy and antioxidants. Another study has shown that cocoa-enriched diets improved spatial memory in a mouse model of AD. So, there is some truth there, although eating chocolate with high fat and sugar contents may offset these potential benefits.
Regarding red wine, one of the components, called resveratrol (polyphenol), may also have a beneficial effect in slowing the progressing of the pathology in a mouse model of AD. Lower levels of amyloid plaques and a reduction in neuroinflammation have been foundl.
Overall, eating chocolate and drinking red wine may be beneficial. The secret is in the choice and quantities.