Tag: cognitive decline

Categories : Diseases, Syndromes and Conditions Neurodegenerative DiseasesTags :

Shingles Increases Risk of Cognitive Decline in Later Life

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The risk was higher for men who were carriers of a gene linked to dementia

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A new study led by investigators from Brigham and Women’s Hospital found that an episode of shingles is associated with about a 20 percent higher long-term risk of subjective cognitive decline. The study’s findings provide additional support for getting the shingles vaccine to decrease risk of developing shingles, according to the researchers. Their results are published in Alzheimer’s Research & Therapy.

“Our findings show long-term implications of shingles and highlight the importance of public health efforts to prevent and promote uptake of the shingles vaccine,” said corresponding author Sharon Curhan, MD, of the Channing Division for Network Medicine at Brigham and Women’s Hospital. “Given the growing number of Americans at risk for this painful and often disabling disease and the availability of a very effective vaccine, shingles vaccination could provide a valuable opportunity to reduce the burden of shingles and possibly reduce the burden of subsequent cognitive decline.”

Shingles, medically known as “herpes zoster,” is a viral infection that often causes a painful rash. Shingles is caused by the varicella zoster virus (VZV), the same virus that causes chickenpox. After a person has chickenpox, the virus stays in their body for the rest of their life. Most of the time, our immune system keeps the virus at bay. Years and even decades later, the virus may reactivate as shingles.

Almost all individuals in the US age 50 years and older have been infected with VZV and are therefore at risk for shingles. There’s a growing body of evidence that herpes viruses, including VZV, can influence cognitive decline. Subjective cognitive decline is an individual’s self-perceived experience of worsening or more frequent confusion or memory loss. It is a form of cognitive impairment and is one of the earliest noticeable symptoms of Alzheimer’s disease and related dementias.

Previous studies of shingles and dementia have been conflicting. Some research indicates that shingles increases the risk of dementia, while others indicate there’s no association or a negative association. In recent studies, the shingles vaccine was associated with a reduced risk of dementia.

To learn more about the link between shingles and cognitive decline, Curhan and her team used data from three large, well-characterized studies of men and women over long periods: The Nurses’ Health Study, the Nurses’ Health Study 2, and the Health Professionals Follow-Up Study. The study included 149,327 participants who completed health status surveys every two years, including questions about shingles episodes and cognitive decline. They compared those who had shingles with those who didn’t.

Curhan designed the study with first author Tian-Shin Yeh, formerly of the Harvard TH Chan School of Public Health. The researchers found that a history of shingles was significantly and independently associated with a higher risk – approximately 20% higher – of subjective cognitive decline in both women and men. That risk was higher among men who were carriers of the gene APOE4, which is linked to cognitive impairment and dementia. That same association wasn’t present in the women.

Researchers don’t know the mechanisms that link the virus to cognitive health, but there are several possible ways it may contribute to cognitive decline. There is growing evidence linking VZV to vascular disease, called VZV vasculopathy, in which the virus causes damage to blood vessels in the brain or body. Curhan’s group previously found that shingles was associated with higher long-term risk of stroke or heart disease.

Other mechanisms that may explain how the virus may lead to cognitive decline include causing inflammation in the brain, directly damaging the nerve and brain cells, and the activation of other herpesviruses.

The limitations of this research include that it was an observational study, information was based on self-report, and included a mostly white, highly educated population. In future studies, the researchers hope to learn more about preventing shingles and its complications.

“We’re evaluating to see if we can identify risk factors that could be modified to help reduce people’s risk of developing shingles,” Curhan said. “We also want to study whether the shingles vaccine can help reduce the risk of adverse health outcomes from shingles, such as cardiovascular disease and cognitive decline.” 

Source: Brigham and Women’s Hospital

Categories : Mental HealthTags :

How Stress Saps Cognitive Reserves, Increasing Dementia Risk

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While mentally stimulating activities and life experiences can improve cognition in memory clinic patients, stress undermines this beneficial relationship. This is according to a new study published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.

Researchers in the late 1980s found that some individuals who showed no apparent symptoms of dementia during their lifetime had brain changes consistent with an advanced stage of Alzheimer’s disease. 

It has since been postulated that so-called cognitive reserve might account for this differential protective effect in individuals. 

Cognitively stimulating and enriching life experiences and behaviours such as higher educational attainment, complex jobs, continued physical and leisure activities, and healthy social interactions help build cognitive reserve. 

Increased risk of dementia

However, high or persistent stress levels are associated with reduced social interactions, impaired ability to engage in leisure and physical activities, and an increased risk of dementia.  

Researchers from Karolinska Institutet have now examined the association between cognitive reserve, cognition, and biomarkers for Alzheimer’s disease in 113 participants from the memory clinic at the Karolinska University Hospital, Huddinge, Sweden. 

They also examined how this association is modified by physiological stress (cortisol levels in saliva) and psychological (perceived) stress. 

Greater cognitive reserve was found to improve cognition, but interestingly, physiological stress appeared to weaken the association.  

“These results might have clinical implications as an expanding body of research suggests that mindfulness exercises and meditation may reduce cortisol levels and improve cognition,” says the study’s lead author Manasa Shanta Yerramalla, researcher at the Department of Neurobiology, Care Sciences and Society. “Different stress management strategies could be a good complement to existing lifestyle interventions in Alzheimer’s prevention.” 

The relatively small sample of participants reduces the possibility of drawing robust conclusions, but the results are generalisable to similar patient groups.  

Link between sleep and cognition 

Moreover, since stress disrupts sleep, which in turn disrupts cognition, the researchers controlled for sleeping medications; they did not, however, consider other aspects of sleep that might impair cognition. 

“We will continue to study the association between stress and sleeping disorders and how it affects the cognitive reserve in memory clinic patients,” says Dr Yerramalla. 

Source: Karolinska Institutet

Categories : Ageing ExerciseTags :

New Insights into How Exercise Slows Age-related Cognitive Decline

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New research published in Aging Cell provides insights into how exercise may help to prevent or slow cognitive decline during aging.

For the study, investigators assessed the expression of genes in individual cells in the brains of mice. The team found that exercise has a significant impact on gene expression in microglia, the immune cells of the central nervous system that support brain function. Specifically, the group found that exercise reverts the gene expression patterns of aged microglia to patterns seen in young microglia.

Treatments that depleted microglia revealed that these cells are required for the stimulatory effects of exercise on the formation of new neurons in the brain’s hippocampus, a region involved in memory, learning, and emotion.

The scientists also found that allowing mice access to a running wheel prevented and/or reduced the presence of T cells in the hippocampus during aging. These immune cells are not typically found in the brain during youth, but they increase with age.

“We were both surprised and excited about the extent to which physical activity rejuvenates and transforms the composition of immune cells within the brain, in particular the way in which it was able to reverse the negative impacts of aging,” said co–corresponding author Jana Vukovic, PhD, of The University of Queensland, in Australia. “It highlights the importance of normalising and facilitating access to tailored exercise programs. Our findings should help different industries to design interventions for elderly individuals who are looking to maintain or improve both their physical and mental capabilities.”

Source: Wiley

Categories : Ageing NeurologyTags :

Do More Mentally Challenging Jobs Protect against Cognitive Decline?

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The harder your brain works at your job, the less likely you may be to have memory and thinking problems later in life, according to a new study published in Neurology®, the medical journal of the American Academy of Neurology. This study does not prove that stimulating work prevents mild cognitive impairment. It only shows an association.

“We examined the demands of various jobs and found that cognitive stimulation at work during different stages in life – during your 30s, 40s, 50s and 60s – was linked to a reduced risk of mild cognitive impairment after the age of 70,” said study author Trine Holt Edwin, MD, PhD, of Oslo University Hospital in Norway.

“Our findings highlight the value of having a job that requires more complex thinking as a way to possibly maintain memory and thinking in old age.”

The study looked at 7000 people and 305 occupations in Norway. Researchers measured the degree of cognitive stimulation that participants experienced while on the job. They measured the degree of routine manual, routine cognitive, non-routine analytical, and non-routine interpersonal tasks, which are skill sets that different jobs demand.

Routine manual tasks demand speed, control over equipment, and often involve repetitive motions, typical of factory work. Routine cognitive tasks demand precision and accuracy of repetitive tasks, such as in bookkeeping and filing.

Non-routine analytical tasks involve analysing information, engaging in creative thinking and interpreting information for others. Non-routine interpersonal tasks include establishing and maintaining personal relationships, motivating others and coaching. Non-routine cognitive jobs include public relations and computer programming.

Researchers divided participants into four groups based on the degree of cognitive stimulation that they experienced in their jobs. The most common job for the group with the highest cognitive demands was teaching. The most common jobs for the group with the lowest cognitive demands were mail carriers and custodians.

After age 70, participants completed memory and thinking tests to assess whether they had mild cognitive impairment. Of those with the lowest cognitive demands, 42% were diagnosed with mild cognitive impairment, compared to 27% for those with the highest cognitive demands.

After adjustment for age, sex, education, income and lifestyle factors, the group with the lowest cognitive demands at work had a 66% higher risk of mild cognitive impairment compared to the group with the highest cognitive demands at work.

“These results indicate that both education and doing work that challenges your brain during your career play a crucial role in lowering the risk of cognitive impairment later in life,” Edwin said. “Further research is required to pinpoint the specific cognitively challenging occupational tasks that are most beneficial for maintaining thinking and memory skills.”

A limitation of the study was that even within identical job titles, individuals might perform different tasks and experience different cognitive demands.

Source: American Academy of Neurology

Categories : NeurologyTags :

Poor Sleep Quality in Midlife Linked to Cognitive Problems Later on

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People who have more disrupted sleep in their 30s and 40s may be more likely to have memory and thinking problems a decade later, according to new research published in Neurology. The study does not however prove that sleep quality causes cognitive decline, it only shows an association.

“Given that signs of Alzheimer’s disease start to accumulate in the brain several decades before symptoms begin, understanding the connection between sleep and cognition earlier in life is critical for understanding the role of sleep problems as a risk factor for the disease,” said study author Yue Leng, PhD, of the University of California, San Francisco.

“Our findings indicate that the quality rather than the quantity of sleep matters most for cognitive health in middle age.”

The study involved 526 people, average age of 40, who were followed for 11 years. Researchers looked at participants’ sleep duration and quality, and had them perform cognitive tests.

Participants wore a wrist activity monitor for three consecutive days on two occasions approximately one year apart to calculate their averages. Participants slept for an average of six hours.

Participants also reported bedtimes and wake times in a sleep diary and completed a sleep quality survey with scores ranging from zero to 21, with higher scores indicating poorer sleep quality. A total of 239 people, or 46%, reported poor sleep with a score greater than five. Participants also completed a series of memory and thinking tests.

Researchers also looked at sleep fragmentation, which measures repetitive short interruptions of sleep. They looked at both the percentage of time spent moving and the percentage of time spent not moving for one minute or less during sleep. Added together, participants had an average sleep fragmentation of 19%.

Researchers then divided participants into three groups based on their sleep fragmentation score. Of the 175 people with the most disrupted sleep, 44 had poor cognitive performance 10 years later, compared to 10 of the 176 people with the least disrupted sleep.

After adjusting for age, gender, race, and education, people who had the most disrupted sleep had more than twice the odds of having poor cognitive performance when compared to those with the least disrupted sleep.

There was no difference in cognitive performance at midlife for those in the middle group compared to the group with the least disrupted sleep.

“More research is needed to assess the link between sleep disturbances and cognition at different stages of life and to identify if critical life periods exist when sleep is more strongly associated with cognition,” Leng said.

“Future studies could open up new opportunities for the prevention of Alzheimer’s disease later in life.”

The amount of time people slept and their own reports of the quality of their sleep were not associated with cognition in middle age.

Source: American Academy of Neurology

Categories : NeurologyTags :

Night-time Fragrances Provide Cognitive Boost that Could Stave off Dementia

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When a fragrance wafted through the bedrooms of older adults for two hours every night for six months, memory recall skyrocketed. Participants in this study experienced a 226% increase in cognitive capacity compared to controls. The researchers say the finding transforms the long-known tie between smell and memory into an easy, non-invasive technique for strengthening memory and potentially deterring dementia. The findings, which appear to pass the ‘sniff test’, are published in the open-access journal Frontiers in Neuroscience.

The project was conducted University of California, Irvine neuroscientists, involving men and women aged 60 to 85 without memory impairment. All were given a diffuser and seven cartridges, each containing a single and different natural oil. People in the enriched group received full-strength cartridges. Control group participants were given the oils in tiny amounts. Participants put a different cartridge into their diffuser each evening prior to going to bed, and it activated for two hours as they slept.

People in the enriched group showed a 226% increase in cognitive performance compared to the control group, as measured by a word list test commonly used to evaluate memory. Imaging revealed better integrity in the brain pathway called the left uncinate fasciculus. This pathway, which connects the medial temporal lobe to the decision-making prefrontal cortex, becomes less robust with age. Participants also reported sleeping more soundly.

Scientists have long known that the loss of olfactory capacity, or ability to smell, can predict development of nearly 70 neurological and psychiatric diseases. These include Alzheimer’s and other dementias, Parkinson’s, schizophrenia and alcoholism. Evidence is emerging about a link between smell loss due to COVID and ensuing cognitive decrease. Researchers have previously found that exposing people with moderate dementia to up to 40 different odours twice a day over a period of time boosted their memories and language skills, eased depression and improved their olfactory capacities. The UCI team decided to try turning this knowledge into an easy and non-invasive dementia-fighting tool.

“The reality is that over the age of 60, the olfactory sense and cognition starts to fall off a cliff,” said Michael Leon, professor of neurobiology & behaviour and a CNLM fellow. “But it’s not realistic to think people with cognitive impairment could open, sniff and close 80 odorant bottles daily. This would be difficult even for those without dementia.”

The study’s first author, project scientist Cynthia Woo, said: “That’s why we reduced the number of scents to just seven, exposing participants to just one each time, rather than the multiple aromas used simultaneously in previous research projects. By making it possible for people to experience the odors while sleeping, we eliminated the need to set aside time for this during waking hours every day.”

The researchers say the results from their study bear out what scientists learned about the connection between smell and memory.

“The olfactory sense has the special privilege of being directly connected to the brain’s memory circuits,” said collaborating investigator Michael Yassa, professor and director of CNLM. “All the other senses are routed first through the thalamus. Everyone has experienced how powerful aromas are in evoking recollections, even from very long ago. However, unlike with vision changes that we treat with glasses and hearing aids for hearing impairment, there has been no intervention for the loss of smell.”

The team would next like to study the technique’s impact on people with diagnosed cognitive loss. The researchers also say they hope the finding will lead to more investigations into olfactory therapies for memory impairment. A product based on their study and designed for people to use at home is expected to come onto the market later this year.

Source: University of California – Irvine

Categories : AgeingTags :

Black Adults Experience Less Cognitive Decline after Retirement

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A study published in the Journal of the American Geriatrics Society found that immediately after retirement, white adults tended to experience a significant decline in cognitive function, whereas Black adults experienced minimal cognitive decline. White men showed the steepest post-retirement cognitive decline across sex/race combinations, whereas Black women showed the least decline.

White women performed better cognitively at retirement than other race/sex subgroups, and after retirement, their cognitive functioning declined at a rate that was slightly less than the average for this study. Results were adjusted for sociodemographics and physical and mental health indicators.

The study, which included 2226 US participants followed for up to 10 years, revealed greater post-retirement cognitive decline among individuals who attended college compared with those who did not.

“The results seem to point to the possibility that better job opportunities could lead to greater cognitive losses after retirement whereas exposure to lifelong structural inequalities may actually ease transition to retirement with respect to cognitive aging,” said lead author Ross Andel, PhD, of Arizona State University’s Edson College of Nursing and Health Innovation.

Source: Wiley

Categories : AgeingTags :

Muscle Adiposity may Indicate Cognitive Decline in Aging

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New research reveals that the level of muscle adiposity (fat content) may indicate a person’s likelihood of experiencing cognitive decline as they age. In the study published in the Journal of the American Geriatrics Society, a five-year increase in fat stored in the thigh muscle was a risk factor for cognitive decline.

This risk was independent of total weight, other fat deposits, and muscle characteristics (such as muscle strength or mass) and also independent of traditional dementia risk factors.

Investigators assessed muscle fat in 1634 adults 69–79 years of age at years 1 and 6 and evaluated their cognitive function at years 1, 3, 5, 8, and 10. Increases in muscle adiposity from year 1 to year 6 were associated with faster and more cognitive decline over time. The findings were similar for Black and White men and women.

“Our data suggest that muscle adiposity plays a unique role in cognitive decline, distinct from that of other types of fat or other muscle characteristics,” said corresponding author Caterina Rosano, MD, MPH, of the University of Pittsburgh’s School of Public Health. “If that is the case, then the next step is to understand how muscle fat and the brain ‘talk’ to each other, and whether reducing muscle adiposity can also reduce dementia risk.”

Source: Wiley

Categories : AgeingTags :

Low Sexual Satisfaction in Middle Age Linked to Cognitive Decline

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Low sexual satisfaction in middle age may serve as an early warning sign for future cognitive decline, according to a new study. The researchers, who tracked associations between erectile function, sexual satisfaction and cognition in hundreds of men aged 56 through 68, found that declines in sexual satisfaction and erectile function were correlated with future memory loss.

The study, published in Gerontologist, is the first to longitudinally track sexual satisfaction in tandem with sexual health and cognition, the researchers state, and its findings point to a potential novel risk factor for cognitive decline.

“What was unique about our approach is that we measured memory function and sexual function at each point in the longitudinal study, so we could look at how they changed together over time,” said Martin Sliwinski, professor of human development and family studies at Penn State and co-author on the study. “What we found connects to what scientists are beginning to understand about the link between life satisfaction and cognitive performance.”

The study explored the relationship between physical changes like the microvascular changes relevant for erectile function, and psychological changes, such as lower sexual satisfaction, to determine how the changes relate to cognition. They examined the shifts starting in middle age because it represents a transition period where declines in erectile function, cognition and sexual satisfaction begin to emerge.

Sliwinski added that while the team discovered a strong correlation between the three health factors, they can only speculate as to the cause.

“Scientists have found that if you have low satisfaction generally, you are at a higher risk for health problems like dementia, Alzheimer’s disease, cardiovascular disease and other stress-related issues that can lead to cognitive decline,” he said. “Improvements in sexual satisfaction may actually spark improvement in memory function. We tell people they should get more exercise and eat better foods. We’re showing that sexual satisfaction also has importance for our health and general quality of life.”

For the study, the researchers used survey data from 818 men who participated in the Vietnam Era Twin Study of Aging. Through neuropsychological tests, such as tests of memory and processing speed, they examined cognitive changes of participants over the 12-year span from age 56 to 68, adjusting for participants’ cognitive ability in young adulthood. Their erectile function and sexual satisfaction were measured alongside cognition, using the International Index of Erectile Function, a self-reported assessment for male sexual health. The researchers then built a statistical model to understand how the three variables changed as individuals aged.

“Research on sexual health has historically focused on quantifiable facets of sexuality like number of sexual partners or frequency of sexual activity,” said Riki Slayday, a doctoral candidate at Penn State and lead author on the study. “What we were interested in is the perception of that activity, how someone feels about their sex life, and how that influences cognitive function, because multiple people could be in the same situation physically but experience completely different levels of satisfaction.”

The study found that decreases in erectile function and sexual satisfaction were both associated with memory decline, which the researchers say points to a connection between psychological and physical health.

“When we mapped the relationship over time, we found increases or decreases in erectile function and sexual satisfaction were associated with concurrent increases or decreases in cognitive function,” Slayday said. “These associations survived adjustment for demographic and health factors, which tells us there is a clear connection between our sex lives and our cognition.”

Prior studies have found a link between microvascular changes and changes in erectile function over time. In fact, the active ingredient in Viagra (Sildenafil) was originally developed to treat cardiovascular problems, Sliwinski explained, so the connection between vascular health and erectile function is well understood. How erectile function connects to other aspects of health should be an area of focus for future research, he added.

Increasing the assessment and monitoring of erectile function as a vital sign of health may help identify those at risk of cognitive decline before their 70s, he said. The researchers note that the older adult population in the US is expected to double over the next 30 years, which means twice as many people will likely enter their 60s and experience declines in erectile function and sexual satisfaction.

“We already have a pill for treating erectile dysfunction. What we don’t have is an effective treatment for memory loss,” Sliwinski said. “Instead of the conversation being about treating ED, we should see that as a leading indicator for other health problems and also focus on improving sexual satisfaction and overall well-being, not just treating the symptom.”

Source: Penn State University

Categories : Ageing Neurodegenerative DiseasesTags :

Difficulty Falling Asleep Linked to Developing Dementia

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Old man
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Adding to the growing body of evidence on sleep disturbances and cognitive impairment, new research published in the American Journal of Preventive Medicine, finds significant links between three measures of sleep disturbance and the risk for developing dementia over a 10-year period. Difficulties falling asleep were linked to higher risk, but not falling asleep again after waking.

The results associate sleep-initiation insomnia (trouble falling asleep within 30 min) and sleep medication use with higher dementia risk. An additional, surprising finding was that people who reported having sleep-maintenance insomnia (trouble falling back to sleep after waking) were less likely to develop dementia over the course of the study.

“We expected sleep-initiation insomnia and sleep medication usage to increase dementia risk, but we were surprised to find sleep-maintenance insomnia decreased dementia risk,” explained lead investigator Roger Wong, PhD, MPH, MSW, an Assistant Professor in the Department of Public Health and Preventive Medicine, SUNY Upstate Medical University. “The motivation behind this research was prompted on a personal level. My father has been experiencing chronic sleep disturbances since the COVID pandemic began, and I was concerned how this would affect his cognition in the future. After reading the existing literature, I was surprised to see mixed findings on the sleep-dementia relationship, so I decided to investigate this topic.”

This research is novel because it is the first to examine how long-term sleep disturbance measures are associated with dementia risk using a nationally representative US older adult sample. Previous research has associated REM sleep behavior, sleep deprivation (less than five hours of sleep), and the use of short-acting benzodiazepines with cognitive decline. Their results for sleep-maintenance insomnia support other recent studies using smaller, separate data samples.

This study used 10 annual waves (2011–2020) of prospective data from the National Health and Aging Trends Study (NHATS), a longitudinal panel study that surveys a nationally representative sample of Medicare beneficiaries aged 65 years and older within the USA. This study included only people who were dementia-free at baseline in 2011.

While the mechanism for decreased dementia risk among those with sleep-maintenance insomnia is still unknown, the investigators theorise that greater engagement in activities that preserve or increase cognitive reserve may thereby decrease dementia risk.

Recent evidence indicates there is a higher prevalence of sleep disturbances among older adults than among other age groups. This could be attributed to a variety of factors including anxiety about the COVID pandemic or warmer nights as a consequence of climate change.

“Older adults are losing sleep over a wide variety of concerns. More research is needed to better understand its causes and manifestations and limit the long-term consequences,” added Dr Wong. “Our findings highlight the importance of considering sleep disturbance history when assessing the dementia risk profile for older adults. Future research is needed to examine other sleep disturbance measures using a national longitudinal sample, whether these sleep-dementia findings hold true for specific dementia subtypes, and how certain sociodemographic characteristics may interact with sleep disturbances to influence dementia risk.”

Source: Elsevier