Category: Dementia

Older adults should be routinely screened for this change.

Losing your sense of smell is an early sign of dementia and poor health.

Older people with a poor sense of smell have a 50 percent increased chance of dying within 10 years, new research finds.

Losing your sense of smell is an important early sign of dementia and Parkinson’s.

A loss of the sense of smell is linked to a doubling in dementia risk.

The reason is that the part of the brain that deals with smell (the olfactory bulb) is one of the first to be affected by dementia.

However, this new study finds that a poor sense of smell is a broader warning sign.

Professor Honglei Chen, study co-author, said:

“Poor sense of smell becomes more common as people age, and there’s a link to a higher risk for death.

Our study is the first to look at the potential reasons why it predicts a higher mortality.”

The conclusions come from a study of almost 2,300 people aged 71 to 82 who were followed over 13 years.

All were given smell tests of 12 common odours.

The results showed that adults with a poor, as opposed to good, sense of smell had a 46 percent higher chance of dying over 10 years.

Dementia and Parkinson’s disease, though, did not explain all the additional risk, said Professor Chen:

“We don’t have a reason for more than 70% of the increased risk.

We need to find out what happened to these individuals.”

Professor Chen thinks older adults should be routinely screened for their sense of smell:

“It tells us that in older adults, impaired sense of smell has broader implications of health beyond what we have already known.

Incorporating a sense of smell screening in routine doctor visits might be a good idea at some point.

It’s always prudent to talk to a physician about your health concerns.”

The study was published in the Annals of Internal Medicine (Liu et al., 2019).

Be aware of this unusual sign of dementia.

Hearing loss is linked to a higher risk of dementia, new research concludes.

Older people with severe hearing loss are at a 54% greater risk of experiencing cognitive decline.

The study included 10,107 men — average age 62 — who were followed over eight years.

All were asked standard questions about their thinking and reasoning skills every four years.

The results showed that those with mild hearing loss were at a 30% higher risk of cognitive decline, while moderate hearing loss was linked to a 43% higher risk.

Dr Sharon Curhan, the study’s first author, said:

“Dementia is a substantial public health challenge that continues to grow.

There is no cure, and effective treatments to prevent progression or reverse the course of dementia are lacking.

Our findings show that hearing loss is associated with new onset of subjective cognitive concerns which may be indicative of early stage changes in cognition.

These findings may help identify individuals at greater risk of cognitive decline.”

The researchers checked if hearing aids made any difference, but their findings were inconclusive, suggesting their influence is modest at best.

Dr Curhan said:

“Whether there is a temporal association between hearing loss and cognitive decline and whether this relation is causal remains unclear.

We plan to conduct further longitudinal studies of the relation of hearing loss and cognition in women and in younger populations, which will be informative.”

The study was published in the journal Alzheimer’s & Dementia (Curhan et al., 2019).

Mouse study reverses memory loss in mice with Alzheimer’s.

Memory loss caused by Alzheimer’s disease has been reversed in mice, reports a new study.

Alzheimer’s disease — the most common form of dementia –results from both genetic and environmental factors, and is currently untreatable.

Scientists have discovered, though, that the disease interferes with electrical signalling in part of the brain responsible for memory.

Using techniques based on epigenetics, the researchers were able to reverse the memory loss.

Epigenetics involves how instructions contained in DNA are expressed in cells.

Professor Zhen Yan, the study’s first author, said:

“We have not only identified the epigenetic factors that contribute to the memory loss, we also found ways to temporarily reverse them in an animal model of AD.”

The scientists found that Alzheimer’s caused neurons in the frontal cortex to gradually lose glutamate receptors.

By inhibiting an enzyme, they were able to restore memory in mice.

Professor Yan said:

“When we gave the Alzheimer’s animals this enzyme inhibitor, we saw the rescue of cognitive function confirmed through evaluations of recognition memory, spatial memory and working memory.

We were quite surprised to see such dramatic cognitive improvement.

At the same time, we saw the recovery of glutamate receptor expression and function in the frontal cortex.”

While the drug only worked on the mice for one week, it is hoped the method can be refined to make it more powerful.

Epigenetics is powerful because it can target the effects of more than one gene, said Professor Yan:

“An epigenetic approach can correct a network of genes, which will collectively restore cells to their normal state and restore the complex brain function.

We have provided evidence showing that abnormal epigenetic regulation of glutamate receptor expression and function did contribute to cognitive decline in Alzheimer’s disease.

If many of the dysregulated genes in AD are normalized by targeting specific epigenetic enzymes, it will be possible to restore cognitive function and behavior.”

The study was published in the journal Brain (Yan et al., 2019).