Category: Dementia

Sleep disturbance is common in dementia, but the reason is unclear.

Getting less REM sleep — the phase in which we dream — is linked to dementia, a study finds.

During sleep the brain cycles between periods of deep sleep and then up towards shallower periods of sleep in which we tend to dream, whether we remember those dreams or not.

During REM sleep the eyes move rapidly from side-to-side (hence Rapid Eye Movement Sleep).

Brain activity also increases and our pulses quicken.

Dr Matthew P. Pase, the study’s first author, said:

“Sleep disturbances are common in dementia but little is known about the various stages of sleep and whether they play a role in dementia risk.

We set out to discover which stages of sleep may be linked to dementia and while we did not find a link with deep sleep, we did with REM sleep.”

The research involved 321 people, average age 67, who were followed for 12 years.

The results showed that people who eventually developed dementia spent less time in REM sleep than those that did not.

For each 1% decrease in REM sleep, the dementia risk increased 9%.

In this study, average REM sleep for those that did not develop dementia was 20%.

For those that did develop dementia it was 17%.

Dr Pase said:

“Our findings point to REM sleep as a predictor of dementia.

The next step will be to determine why lower REM sleep predicts a greater risk of dementia.

By clarifying the role of sleep in the onset of dementia, the hope is to eventually identify possible ways to intervene so that dementia can be delayed or even prevented.”

The other stages of sleep were not linked to dementia, the researchers found.

The study was published in the journal Neurology (Pase et al., 2017).

The types of fruit that can reduce cognitive aging and lower the risk of Alzheimer’s in midlife.

Daily consumption of strawberries or blueberries may lower the odds of dementia and Alzheimer’s disease in middle-aged men and women.

According to a study, both strawberries and blueberries contain effective antioxidants that help prevent the risk of late-life dementia.

Midlife adults can get the optimal health effect if consuming at least one cup of whole strawberries or blueberries per day.

Anti-aging antioxidants

A group of antioxidants called anthocyanins are responsible for the red, purple, or blue pigments of fruits and flowers.

Studies show that these antioxidants, due to their anti-inflammatory effect, can lower the risk of heart disease, type-2 diabetes and cancer.

Berries are rich in anthocyanins and several nutrients such as ellagic acid, that is known for its anti-aging effects, and improving memory and other cognitive skills.

Professor Robert Krikorian, the study’s first author, said:

“Both strawberries and blueberries contain antioxidants called anthocyanins, which have been implicated in a variety of berry health benefits such as metabolic and cognitive enhancements.

There is epidemiological data suggesting that people who consume strawberries or blueberries regularly have a slower rate of cognitive decline with aging.”

Slow cognitive decline

Around half of the American adult population with prediabetes are middle-aged.

This group are more vulnerable to memory loss and cognitive decline.

Past research has suggested that eating strawberries can boost cardiovascular health by improving insulin sensitivity and lowering blood glucose levels.

This study investigated whether strawberry consumption provides any health benefit in overweight middle-aged individuals with self-reported cognitive decline.

Professor Krikorian said:

“This study assessed whether strawberry consumption might improve cognitive performance and metabolic health in this population, and if so, whether there might be an association between cognitive enhancement and reduced metabolic disturbance.”

One cup of strawberries

The participants in this study received every day a sachet of strawberry powder, equal to one cup of whole strawberries, for 3 months.

During the study period, the participants took various tests to measure their cognitive abilities such as long-term memory, as well as their emotional state such as mood, anxiety, and depressive symptoms.

The strawberry-treated group experienced a significant reduction in memory interference.

Professor Krikorian said:

“Reduced memory interference refers to less confusion of semantically related terms on a word-list learning test.

This phenomenon generally is thought to reflect better executive control in terms of resisting intrusion of non-target words during the memory testing.”

Furthermore, the strawberry-treated participants also experienced less depressive symptoms.

Professor Krikorian said the positive effects can be due to:

“…enhanced executive ability that would provide better emotional control and coping and perhaps better problem-solving.”

Lowering brain inflammation

Other studies have found that higher consumption of strawberries improves metabolic measures such as lowering insulin levels.

Professor Krikorian pointed out:

“Those studies generally used higher dosages of strawberry powder than in our research, and this could have been a factor.”

It seems the improvement of cognitive function by eating strawberries could be due to decreased brain inflammation.

Professor Krikorian said:

“Executive abilities begin to decline in midlife and excess abdominal fat, as in insulin resistance and obesity, will tend to increase inflammation, including in the brain.

So, one might consider that our middle-aged, overweight, prediabetic sample had higher levels of inflammation that contributed to at least mild impairment of executive abilities.

Accordingly, the beneficial effects we observed might be related to moderation of inflammation in the strawberry group.”

Related

• One cup of cranberries a day reduces the risk of neurodegenerative disorders.
• Lingonberry juice lowers blood pressure in the long-term.
• Flavonoid-rich foods can reduce blood pressure levels.
• Blackcurrants are found to improve mood.

The study was published in the journal of Nutrients  (Krikorian et al., 2023).

It provides an extra layer of protection against dementias like Alzheimer’s disease.

Being married or in a close relationship almost halves the risk of developing dementia, research finds.

It is likely because those in close relationships have an extra layer of protection against depression.

Depression is a known risk factor for dementia.

Professor Eef Hogervorst, who led the study, explained it could also be down to a healthier lifestyle:

“It might be because other studies often found that married men on average have healthier lifestyles than single men – such as better diets, less alcohol, less smoking and more and earlier health services visits.

Another explanation could be that married couples will try to cope with dementia symptoms on their own for longer before health services are involved.”

The six-year study tracked 6,677 people aged between 52 and 90 to look at the connection between close relationships and Alzheimer’s disease.

It emerged that relationship quality was more important in protecting people against dementia than quantity of relationships.

Professor Hogervorst continued:

“Single people will need help to cope with their symptoms earlier.

Not being married almost doubled the risk for developing dementia.

On the other hand, having close relationships independently reduced the risk by 60%.

We did not find that social isolation per se increased risk but that feeling lonely did, by 44%.”

Along with being single, other risk factors for dementia included heart disease, hypertension, and depression.

Professor Hogervorst said:

“We know that depression and heart disease risk factors are risk factors for dementia.

And, loneliness had a similar strength of association as the heart disease risk factors.

This has been mentioned before for other morbidities where loneliness was said to be as bad for health as smoking.

We are social creatures and reduction of stress through social support may be more important than previously thought.”

Enhancing older people’s relationship quality could be one key to staving off dementia.

Professor Hogervorst said:

“Being lonely can be associated with depression and this has been associated with dementia.

As most people with dementia stay at home most of the time, we try to use technology to do activities which include others, such as modified forms of Facebook, cognitive stimulation therapy and exercises in virtual groups.”

The study was published in The Journals of Gerontology (Rafnsson et al., 2017).

At least 5 million Americans are living with Alzheimer’s.

Having moderate or severe anxiety in midlife is linked to dementia later on, research finds.

Anxiety is strongly linked to the personality trait of neuroticism, which includes sadness, irritability and self-consciousness.

The extra risk could be related to the stress caused by a mental health condition.

The stress response to anxiety could accelerate the aging process in the brain, increasing cognitive decline.

Depression has already been linked to a doubling of the risk in developing dementia.

Tackling anxiety and depression in midlife could be a way to reduce dementia risk, the study’s authors write:

“Non-pharmacological therapies, including talking therapies, mindfulness-based interventions, and meditation practices, that are known to reduce anxiety in midlife, could have a risk-reducing effect, although this is yet to be thoroughly researched.”

The study was a meta-analysis, a type of research that pools together the results of other studies.

The researchers found four large studies examining the link between dementia and anxiety that together included almost 30,000 people.

All four studies found that moderate to severe anxiety was linked to developing dementia later on.

The researchers write:

“Clinically significant anxiety in midlife was associated with an increased risk of dementia over an interval of at least 10 years.”

Dr Sara Imarisio, Head of Research at Alzheimer’s Research UK, said:

“Mental health conditions like anxiety and depression have been linked to dementia before and many overlapping symptoms make a dementia diagnosis difficult.

This review took a high-quality approach, combining findings from four existing studies exploring anxiety as a risk factor for dementia.

[…]

It’s important to remember that just because there is an association between the two factors does not necessarily mean that anxiety causes dementia.

Dementia is caused by a complex mix of risk factors including age and genetics and although this study looked at dementia in people more than ten years after being diagnosed with anxiety, we know the diseases leading to dementia can begin in the brain up to twenty years before any symptoms show.”

The study was published in the journal BMJ Open (Gimson et al., 2018).

The food that protects against cognitive decline.

Eating seafood once a week, or food that contains omega-3 fatty acids, may protect against age-related memory loss.

The study found that people who ate seafood less than once a week had a steeper mental decline with age.

Dr Martha Clare Morris, who led the study, said:

“This study helps show that while cognitive abilities naturally decline as part of the normal aging process, there is something that we can do to mitigate this process.”

For the research, 915 people were followed for around 5 years.

They all came from retirement communities and public housing in Illinois and their average age was over 80.

All had memory tests and reported how much seafood they ate.

This included foods like fish cakes, tuna sandwiches, shrimp and crab.

The results showed that people who ate more seafood had better semantic memory: this is something like general knowledge.

Consuming more seafood was also linked to stronger perceptual skills.

The study was published in the journal Neurology (van de Rest et al., 2016).

The study included almost 350 people whose sleep and cognitive function were tracked over around two decades.

Getting only 1 percent less deep sleep each year increases the risk of dementia by 27 percent.

Maintaining or enhancing deep sleep, research suggests, could help to reduce dementia risk.

During sleep the brain cycles between periods of deep sleep and then up towards shallower periods of sleep in which we tend to dream, whether we remember or not.

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

Dr Matthew Pase, study co-author, said:

“Slow-wave sleep, or deep sleep, supports the aging brain in many ways, and we know that sleep augments the clearance of metabolic waste from the brain, including facilitating the clearance of proteins that aggregate in Alzheimer’s disease.

However, to date we have been unsure of the role of slow-wave sleep in the development of dementia.

Our findings suggest that slow wave sleep loss may be a modifiable dementia risk factor.”

Reduced deep sleep

The study included almost 350 people whose sleep and cognitive function were tracked over around two decades.

With age people tended to get less deep sleep, but those whose deep sleep reduced more over the years were at increased risk of developing dementia.

Dr Pase said:

“We also examined whether genetic risk for Alzheimer’s Disease or brain volumes suggestive of early neurodegeneration were associated with a reduction in slow-wave sleep.

We found that a genetic risk factor for Alzheimer’s disease, but not brain volume, was associated with accelerated declines in slow wave sleep.”

Related

• Getting less REM sleep — the phase in which we dream — is linked to dementia.
• Spending less time in deep sleep is linked to loss of brain cells and dementia.
• People who sleep for too little or too long are at a higher risk of cognitive decline and dementia.

The study was published in the journal JAMA Neurology (Himali et al., 2023).

Evidence for a major cause of dementia confirmed.

People with a higher body-mass index are more likely to develop dementia, research finds.

Being classed as overweight rather than in the normal range increases the dementia risk by 16-33%.

For a person who is 170cm (5’7″), for example, carrying an extra 14.5kg (32lbs) over the ideal weight, will increase their dementia risk between 16 and 33%.

Being classed as obese (an additional 14.5kg) adds the same amount of dementia risk again, making a total of up to 66%.

The study analysed data from 1.3 million adults in the US and Europe.

Professor Mika Kivimäki, the study’s first author, said:

“The BMI-dementia association observed in longitudinal population studies, such as ours, is actually attributable to two processes.

One is an adverse effect of excess body fat on dementia risk.

The other is weight loss due to pre-clinical dementia.

For this reason, people who develop dementia may have a higher-than-average body mass index some 20 years before dementia onset, but close to overt dementia have a lower BMI than those who remain healthy.

The new study confirms both the adverse effect of obesity as well as weight loss caused by metabolic changes during the pre-dementia stage.”

Previous studies have given conflicting messages about the effect of obesity on dementia.

Some have suggested more weight may have a protective effect, others, like this one, the reverse.

The study was published in the journal Alzheimer’s & Dementia (Kivimäki et al., 2017).

Adhering to this diet could not only lower the risk of heart disease but also boost cognitive function.

Heart healthy diets designed to lower blood pressure can also improve memory and thinking in later life.

According to a study, middle-aged women who adopt a blood pressure lowering diet are 17 percent less likely to experience signs of cognitive decline such as memory loss, poor thinking and reasoning years later.

Adhering to a healthy eating style such as the Dietary Approaches to Stop Hypertension diet (DASH) not only lowers the risk of heart disease but also can boost cognitive function.

The study focused on women as over two-thirds of people with Alzheimer’s disease are female.

Alzheimer’s is the most common type of dementia, which gradually ruins memory and thinking skills.

It is estimated that nearly 7 million Americans age 65 and older are living with Alzheimer’s disease, and the figure is likely to double by 2060.

Professor Yu Chen, the study’s senior author, said:

“Subjective complaints about daily cognitive performance are early predictors of more serious neurocognitive disorders such as Alzheimer’s.

With more than 30 years follow-up, we found that the stronger the adherence to a DASH diet in midlife, the less likely women are to report cognitive issues much later in life.”

The DASH diet

The DASH diet plan involves eating lots of fruit, vegetables and whole grains and also includes fish, poultry, non-fat or low fat dairy, nuts, seeds, legumes, and vegetable oils.

It also encourages eating foods that are high in magnesium, calcium, and potassium but limits foods that are high in cholesterol, saturated fat, sugar, salt, and sodium.

The diet is mainly designed to combat high blood pressure and so the risk of heart disease but it also improves cognitive function.

Hypertension in middle-age is also a risk factor for vascular cognitive impairment, a condition that damages the brain’s blood vessels, leading to cognitive decline, Alzheimer’s disease and other types of dementia.

Start in midlife

The study enrolled 5,116 women with a 30-year follow up.

They assessed participants’ levels of cognitive impairment, which can potentially lead to dementia in later life.

Typical cognitive issues include forgetting recent events or conversations or failing to navigate familiar roads, or remember shopping lists.

The results showed that women who consumed the DASH diet were 17 percent less likely to have such cognitive problems.

Ms Yixiao Song, the study’s first author, said:

“Our data suggest that it is important to start a healthy diet in midlife to prevent cognitive impairment in older age.”

Dr Fen Wu, study co-author, said:

“Following the DASH diet may not only prevent high blood pressure, but also cognitive issues.”

Related

• Diets containing small amounts of animal products may lower blood pressure.
• Exercise plus following the DASH diet leads to a reduction in blood pressure and weight loss.
• Drinking a low-sodium vegetable juice can quadruple weight loss.
• Eating blueberries could help improve memory and cognitive function.

The study was published in the journal Alzheimer’s & Dementia (Song et al., 2023).