Category: Dementia

The non-prescription drugs which new study links to dementia risk.

Commonly used antidepressants and hayfever drugs, among others, have been linked to an increased risk of developing dementia, a new study finds.

The drugs are often taken by older people, as Professor Shelly Gray, the study’s first author, explained:

 “Older adults should be aware that many medications — including some available without a prescription, such as over-the-counter sleep aids — have strong anticholinergic effects.

And they should tell their health care providers about all their over-the-counter use.

But of course, no one should stop taking any therapy without consulting their health care provider.

Health care providers should regularly review their older patients’ drug regimens — including over-the-counter medications — to look for chances to use fewer anticholinergic medications at lower doses.”

Four commonly used drugs which have strong anticholinergic effects are:

1. Doxepin (Sinequan) – an older antidepressant.
2. Chlorpheniramine (Chlor-Trimeton) – an antihistamine used to treat hayfever.
3. Diphenhydramine (Benadryl) – another antihistamine often used to treat hayfever and sometimes used to aid sleep.
4. Oxybutynin (Ditropan) – for bladder control.

The study, which is published in JAMA Internal Medicine, tracked 3,434 people over the age of 65 who had no signs of dementia (Gray et al., 2015).

They were followed up over 7 years, during which time 797 developed dementia.

The results showed that the more of these drugs people took, the greater their risk of developing dementia.

One-fifth of the drugs had been bought over-the-counter without prescription.

The authors suggest that taking any of these drugs would put people at greater risk if taken for three years or more at these doses:

• 10 mg/day of doxepin,
• 4 mg/day of chlorpheniramine,
• or 5 mg/day of oxybutynin.

The first three can be substituted for other drugs which do not carry the dementia risk, the third cannot.

Unfortunately, the study also suggests that the damage caused by taking these medications may be irreversible.

Professor Gray said:

“If providers need to prescribe a medication with anticholinergic effects because it is the best therapy for their patient, they should use the lowest effective dose, monitor the therapy regularly to ensure it’s working, and stop the therapy if it’s ineffective.”

Image credit: JLA

Breakthrough in detecting brain toxins linked to common brain disease.

A new type of brain scan which can detect the toxins which cause Alzheimer’s disease has been developed by scientists at Northwestern University.

The test, which uses nanotechnology, identifies the early signs of dementia and could be used to both monitor and combat the disease.

The areas of the brain which contain the amyloid beta toxins are seen on the brain scan as large dark patches.

The new test is a breakthrough because previously it was only possible to detect the amyloid plaques — once these have developed it is probably too late for any effective therapy.

The researchers ran the test on both live animals and on brain tissue from people who had Alzheimer’s and those who did not.

Professor William L. Klein, who led the study, said:

“We have a new brain imaging method that can detect the toxin that leads to Alzheimer’s disease.

Using MRI, we can see the toxins attached to neurons in the brain.

We expect to use this tool to detect this disease early and to help identify drugs that can effectively eliminate the toxin and improve health.”

The research, which is published in the journal Nature Nanotechnology, uses a magnetic nanostructure which can be seen by an MRI machine (Viola et al., 2014).

This magnetic nanostructure is attached to an antibody that seeks out the amyloid beta brain toxins.

Together the two parts of the tracer are able to track down and make the toxins detectable by the MRI (below).

In the research the tracer was administered to mice through their noses, since this is one of the shortest routes into the brain.

Kirsten L. Viola, the study’s first author, said:

“While preliminary, the data suggests the probe could be used not only as a diagnostic tool but also as a therapeutic.”

Professor Vinayak P. Dravid, another of the study’s authors and a materials scientist, said:

“Non-invasive imaging by MRI of amyloid beta oligomers is a giant step forward towards diagnosis of this debilitating disease in its earliest form.

This MRI method could be used to determine how well a new drug is working.

If a drug is effective, you would expect the amyloid beta signal to go down.”

Image credit: Viola et al., Nature Nanotechnology, 2014.

Missing out on this kind of sleep can lead to poor memory and dementia.

Spending less time in slow-wave or deep sleep is linked to the loss of brain cells that can lead to dementia, a new study finds.

Slow-wave sleep, which occurs mostly in the first three hours of the night, is when the brain processes thoughts and memories.

The study also found that people with lower levels of oxygen in their blood — typical those with sleep apnea or emphysema — were more likely to have brain abnormalities that lead to dementia.

To reach these conclusions, published in the journal Neurology, the researchers carried out sleep tests on 167 men with an average age of 84 (Gelber et al., 2014).

All the men in the study were followed up until death, when brain cell loss and any abnormalities associated with Alzheimer’s disease were assessed.

Men who spent the shortest time in slow-wave sleep were more than twice as likely to have brain cell loss as those who had the most slow-wave sleep.

Similarly, men whose blood-oxygen levels were the lowest were seven times more likely to have abnormalities in their brain that are associated with dementia.

The results also showed that those who got the most slow-wave or deep sleep performed better on tests of both thinking and memory.

Dr. Rebecca P. Gelber, who led the study, said:

“These findings suggest that low blood oxygen levels and reduced slow wave sleep may contribute to the processes that lead to cognitive decline and dementia.

More research is needed to determine how slow wave sleep may play a restorative role in brain function and whether preventing low blood oxygen levels may reduce the risk of dementia.”

Image credit: Alex

A brain network which links dementia and schizophrenia has been discovered.

A specific brain network which is vulnerable to dementia and schizophrenia has been newly identified.

The study, which is published in the journal Proceedings of the National Academy of Sciences, focused on the structure of the brain’s grey matter, the nerve cells which store and process information (Douaud et al., 2014).

The neuroscientists found that a wide-ranging network in the brain developed late in adolescence and also started to degenerate early with aging.

Dr. Gwenaëlle Douaud, the study’s first author, explained:


”Our results show that the same specific parts of the brain not only develop more slowly, but also degenerate faster than other parts.

These complex regions, which combine information coming from various senses, seem to be more vulnerable than the rest of the brain to both schizophrenia and Alzheimer’s, even though these two diseases have different origins and appear at very different, almost opposite, times of life.”

To reach these conclusions, researchers scanned the brains of 484 people who were between 8 and 85-years-old.

They wanted to see how the brain’s structure naturally changes with age.

What they saw was that there is a network of regions in the brain which tend to develop together and which also degenerate together in later life.

The network reaches through many important parts of the brain, connecting areas involved in higher-order thinking.

The findings fit with a theory first put forward in the 1880s about how dementia develops.

The ‘retrogenesis’ theory states that in Alzheimer’s disease, the brain degenerates in the reverse order to how it originally developed.

In the early stages of dementia, a person’s mental faculties can regress to around those of an 11-year-old, then, over the next four or five years, regresses still further back to the level of a 4- or 5-year-old.

Professor Hugh Perry, of the Medical Research Council, said:

“Early doctors called schizophrenia ‘premature dementia’ but until now we had no clear evidence that the same parts of the brain might be associated with two such different diseases.

This large-scale and detailed study provides an important, and previously missing, link between development, ageing and disease processes in the brain.

It raises important issues about possible genetic and environmental factors that may occur in early life and then have lifelong consequences.

The more we can find out about these very difficult disorders, the closer we will come to helping sufferers and their families.”

Image credit: US Air Force

Brain aging and dementia dramatically slowed by special diet, new study finds.

Neuroscientists have shown that a calorie-restricted diet almost stops gene expressions related to aging and dementia.

Dr. Stephen D. Ginsberg, who presented the new study’s results at the Society for Neuroscience annual meeting, said:

“Our study shows how calorie restriction practically arrests gene expression levels involved in the aging phenotype — how some genes determine the behavior of mice, people, and other mammals as they get old.”

Mice in the study were fed 30% fewer calories, which likely reduced some of the aspects of aging which can lead to diseases like Alzheimer’s.

The life-preserving effect of calorie restriction in animals has been known for some time, but the same effect is not proven in humans.

This study is the first to examine how a calorie restricted diet affects the expression of over 10,000 genes.

Female mice were chosen for this study because, like female humans, they are more susceptible to dementia than males.

The effect of the restricted diet was tested by examining the hippocampal region of the brain, which is one of the first to be affected by Alzheimer’s.

The hippocampus is central to learning and memory, and damage to this area with aging is one of the main causes of the symptoms of Alzheimer’s disease.

The results showed that the calorie restricted diet almost stopped the natural rise and fall of almost 900 different genes related to memory and aging.

Exactly how this huge range of changes provides a protective effect against the effects of aging is not yet known.

While the results do not point to a “fountain of youth,” Dr. Ginsberg said it does:

“…add evidence for the role of diet in delaying the effects of aging and age-related disease.”

• Read on: 10 Ways to Prevent Alzheimer’s Disease