Scientists may have moved one step closer to a cure for Alzheimer’s after discovering subtle signals in the brains of people most susceptible to the disease.
It has long been believed that this memory-destroying disease is caused by a build-up of the proteins amyloid and tau in the brain.
Although most aging brains contain some amount of these proteins, a significant amount can form plaques and tangles, which are thought to be the cause of dementia symptoms.
But now Canadian researchers have discovered an intriguing change in the brain that can occur long before the plaques show up on scans, but it is likely that they will develop.
The team from McGill University in Montreal found that people with reduced electrical activity in specific brain areas are more likely to develop plaques that cause dementia.
While most aging brains have some levels of both proteins, significant amounts of them can form plaques and tangles — and this is believed to be the cause of dementia symptoms.
Alzheimer’s disease is the most common cause of dementia. The disease can cause anxiety, confusion and loss of short-term memory.
In the study, scientists analyzed two separate brain scans of more than 100 volunteers, all with a family history of Alzheimer’s.
The first method tracked the location of proteins in the brain, while the second recorded brain activity in these areas.
They found that those with higher amyloid levels showed a hyperactive brain, or higher-frequency brain activity.
In comparison, people with both amyloid and tau plaques in their brains showed signs of hypoactivity, where brain activity slows.
Cognitive testing also showed that volunteers with higher levels of both proteins were more likely to suffer from memory loss and a shorter attention span.
Writing in the diary Nature NeuroscienceAccording to the scientists, their findings suggest that higher levels of these proteins may lead to altered brain activity, which can be detected before cognitive symptoms emerge.
Researchers now hope to rescan the same 104 participants to see whether the buildup of these two proteins further slows brain activity.
They also want to find out whether this is a reliable prediction of cognitive decline.
Jonathan Gallego Rudolf, a neuroimaging expert and lead author of the study, said: ‘Our study provides direct evidence in humans for the hypothesized shift in neurophysiological activity, from neural hyper- to hypoactivity, and its association with longitudinal cognitive decline.
‘These results are consistent with findings from animal and computer models.
‘They also contribute to increasing our understanding of the pathological mechanisms underlying the preclinical stage of Alzheimer’s disease.’
In the UK, an estimated 944,000 people have dementia, while in the US the figure is estimated at 7 million.
Alzheimer’s affects about six out of ten people with dementia.
Memory problems, problems with thinking and reasoning, and language problems are common early symptoms of the condition, which worsen over time.
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The number of dementia cases is expected to increase dramatically in the coming years, and a low-cost screening method is essential to address this challenge.
An analysis by Alzheimer’s Research UK found that 74,261 people will die from dementia in 2022, compared to 69,178 the year before, making it the biggest cause of death in the country.
This is according to new research published yesterday that shows that a diet rich in flavonoids – plant substances found in foods such as tea, red wine, berries and dark chocolate – can significantly reduce the risk of the incurable disease.
Scientists believe they have a protective effect on brain cells and help block the formation of beta-amyloid plaque.
Researchers from Queen’s University Belfast analysed six years of dietary data from more than 120,000 British adults aged 40 to 70.
They found that consuming six additional servings of flavonoid-rich foods per day, particularly berries, tea and red wine, was associated with a 28 percent lower risk of dementia.