Men May Be More Susceptible to Mild Cognitive Impairment than Women

MCI is often considered a precursor to dementia and Alzheimer's disease, although that view remains controversial.

Men may be more vulnerable than women to developing mild cognitive impairment (MCI) as they age, according to new research from the Mayo Clinic.

MCI — defined as a decline in thinking and memory skills that's more pronounced than that typically associated with aging — is often considered a precursor to dementia and Alzheimer's disease, although that view remains controversial.

The finding that more older men than older women develop MCI was "very surprising" because women are generally believed to have higher rates of dementia, said Dr. Rosebud Roberts, an epidemiologist at Mayo and the lead author of the study, in a phone interview Thursday.

The finding suggests, she added, that the progression from MCI to dementia may be different for each gender.

Confirmation of previous finding:

If this study's results seem like déjà vu to you, it's because Mayo researchers reported in 2010 that the prevalence of MCI was higher in men than in women. But that finding reflected only a snapshot of what was happening in a population at a single moment. The current study followed healthy people for several years and observed how many developed MCI.

"This is a more robust type of study, a more definitive study," said Roberts.
For the study, Roberts and her colleagues followed 1,450 residents of Minnesota's Olmstead County. The participants, aged 70 to 89 at the study's onset, were given neurological tests and evaluations every 15 months for an average of about three years. All were free of signs of cognitive decline at the start of the study.

By the study's end, 296 had developed MCI — and the rate of those cases was significantly higher among men (72 per 1,000 people) than among women (57 per 1,000).
The study found that individuals who were unmarried or who had not attended college were also more likely to develop MCI, but the more-men-then-women finding is the one that has researchers perplexed.

As Dr. Kenneth Rockwood, a professor of geriatric medicine at Dalhouse University in Nova Scotia, notes in an editorial accompanying the Mayo study, "it is unclear how to square more men in the at-risk state not translating into more men with dementia."

After all, studies have generally not found men to have the higher risk of dementia. In Olmstead County, said Roberts, the dementia risk is the same for men and women, but other research, particularly from Europe, suggests the risk is higher in women.

"We are now trying to find out what happens when men and women develop MCI," Roberts said. "One of our hypotheses is that women could possibly progress faster to dementia once they develop MCI, whereas men might stay in the MCI phase for longer. We are currently studying this."
"If women progress faster," she added, "then even if men are staying at the same rate, we might find that there is no sex difference in dementia or we may find women may have a higher incidence of dementia. That's the next story that remains to be told."

A valid predictor?

Of course, the Mayo study is built on the assumption that MCI is a valid predictor of dementia. But not everybody accepts that idea, as I reported when the 2010 Mayo study was published.
"[MCI] is an example of labeling what is a continuum of brain aging that we all go through," Dr. Peter J. Whitehouse, a neurologist and founder of the Memory and Cognition Center at Case Western Reserve University and one of MCI's leading skeptics, said.

No one can say with any certainty, he added back then, which people with MCI will go on to develop dementia and which ones won't.

As Roberts herself acknowledged, only about 10 percent of people with MCI go on to develop full-blown dementia. That compares to about 1 percent of people without MCI, she said.
That means, of course, that 90 percent of people with MCI will never develop dementia.
There's also the problem of reversion. In the current Mayo study, for example, one-third of the people diagnosed with MCI (or 12 percent per year) were later diagnosed at least once during the study as not having the condition.

In his editorial, Rockwood speculates that the positive reversal of symptoms seen in the Mayo study may indicate that "cognitive aging represents not just relentless decline — the brain as innocent bystander — but the outcomes of a struggle between insults and repair mechanisms."
Or could the reversion simply indicate, as Whitehouse claims, that MCI is so ill-defined that it is meaningless as a quantifier of dementia risk?

A need for prevention

One thing that everybody involved in dementia research can agree on is the need for more prevention, which includes reducing the incidence of the usual suspects: obesity, type 2 diabetes and high blood pressure.

"If we could reduce the burden of these diseases in the population, we hope we can reduce the risk of MCI and dementia," said Roberts.

The Mayo Clinic study appears in the Jan. 25 issue of the journal Neurology.

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Program Boosts Cognition in Older Adults

More Evidence for the Cognitive Training Revolution

A program designed to boost cognition in older adults also increased their openness to new experiences, researchers report, demonstrating for the first time that a non-drug intervention in older adults can change a personality trait once thought to be fixed throughout the lifespan.

Personality psychologists describe openness as one of five major personality traits. Studies suggest that the other four traits (agreeableness, conscientiousness, neuroticism and extraversion) operate independently of a person's cognitive abilities. But openness - being flexible and creative, embracing new ideas and taking on challenging intellectual or cultural pursuits - does appear to be correlated with cognitive abilities.

The new study, published in the journal Psychology and Aging, gave older adults a series of pattern-recognition and problem-solving tasks and puzzles that they could perform at home. Participants ranged in age from 60 to 94 years and worked at their own pace, getting more challenging tasks each week when they came to the lab to return materials.

"We wanted participants to feel challenged but not overwhelmed," said University of Illinois educational psychology and Beckman Institute professor Elizabeth Stine-Morrow, who led the research. "While we didn't explicitly test this, we suspect that the training program - adapted in difficulty in sync with skill development - was important in leading to increased openness. Growing confidence in their reasoning abilities possibly enabled greater enjoyment of intellectually challenging and creative endeavors."

Researchers tested the cognitive abilities and personality traits of 183 participants and a control group of 131 older adults a few weeks before and after the intervention

Read More of This Article

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Exergames May Offer Cognitive Benefits

Exergaming may offer older people cognitive benefits

Exergames — exercise combined with virtual reality — might give a cognitive boost to older people more than regular workouts, researchers have found.

A study published in the February issue of the American Journal of Preventive Medicine focused on 79 men and women ages 58 to 99 who did three months of regular exercise on a stationary bicycle or three months of exergaming on cybercycles.

The cybercycles had a virtual reality display that let riders take part in 3-D tours and compete against a ghost rider avatar. Riders in both groups did the same frequency, intensity and amount of exercise.

Study participants were given cognitive tests at the beginning of the study, at one month and at three months. Those tests measured brain functions such as attention, planning, problem solving and working memory. Their blood also was tested for changes in brain-derived neurotrophic growth factor, which encourages the health and growth of nerve cells.

After three months, those who exercised on the cybercycles did better on cognitive tests than those who worked out on stationary cycles. They also had a 23 per cent reduction in the risk of developing mild cognitive impairment compared to the stationary cyclists. Those in the cyber group saw a bigger rise in brain-derived neurotrophic growth factor than the regular exercise group.

“Navigating a 3-D landscape, anticipating turns, and competing with others require additional focus, expanded divided attention, and enhanced decision-making,” said lead author Cay Anderson-Hanley in a news release. Anderson-Hanley, in the department of psychology at Union College in Schenectady, N.Y., added: “These activities depend in part on executive function, which was significantly affected.”

The study authors wrote that the added mental exercise required to operate the cybercycles could be the reason for more cognitive benefits. They added that more research is needed to understand what the factors really are, as well as if cycling outdoors can offer the same benefits as virtual rides.



Huffington Post on Brain Aging and Cognitive Enhancement

From Today's News on Brain-Training, a few gems. Nintendo Brain Age was found to improve cognitive performance in a group of healthy adults. When added to those game developers showing efficacy, a whole new age is opening in the success of these tools to really make a difference. Cognitive Labs has been involved in fomenting this nascent industry since the 2000's midpoint, for the interested reader and game-player who wants useful tools that can really speed up the brain.

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Lack of Iron Early in Life May Affect Brain

Iron is a popular topic in health news. Doctors prescribe it for medical reasons, and it's available over the counter as a dietary supplement. And while it's known that too little iron can result in cognitive problems, it's also known that too much promotes neurodegenerative diseases.

Now, researchers at UCLA have found that in addition to causing cognitive problems, a lack of iron early in life can affect the brain's physical structure as well.

UCLA neurology professor Paul Thompson and his colleagues measured levels of transferrin, a protein that transports iron throughout the body and brain, in adolescents and discovered that these transferrin levels were related to detectable differences in both the brain's macro-structure and micro-structure when the adolescents reached young adulthood.

The researchers also identified a common set of genes that influences both transferrin levels and brain structure. The discovery may shed light on the neural mechanisms by which iron affects cognition, neurodevelopment and neurodegeneration, they said.

Their findings appear in the current online edition of the journal Proceedings of the National Academy of Sciences.

Iron and the proteins that transport it are critically important for brain function. Iron deficiency is the most common nutritional deficiency worldwide, causing poor cognitive achievement in school-aged children. Yet later in life, iron overload is associated with damage to the brain, and abnormally high iron concentrations have been found in the brains of patients with Alzheimer's, Parkinson's and Huntington diseases.

Since both a deficiency and an excess of iron can negatively impact brain function, the body's regulation of iron transport to the brain is crucial. When iron levels are low, the liver produces more transferrin for increased iron transport. The researchers wanted to know whether brain structure in healthy adults was also dependent on transferrin levels.

"We found that healthy brain wiring in adults depended on having good iron levels in your teenage years," said Thompson, a member of UCLA's Laboratory of Neuro Imaging. "This connection was a lot stronger than we expected, especially as we were looking at people who were young and healthy - none of them would be considered iron-deficient.

"We also found a connection with a gene that explains why this is so. The gene itself seems to affect brain wiring, which was a big surprise," he said.

To assess brain volume and integrity, Thompson's team collected brain MRI scans on 615 healthy young-adult twins and siblings, who had an average age of 23. Of these subjects, 574 were also scanned with a type of MRI called a "diffusion scan," which maps the brain's myelin connections and their strength, or integrity. Myelin is the fatty sheath that coats the brain's nerve axons, allowing for efficient conduction of nerve impulses, and iron plays a key role in myelin production.

Eight to 12 years before the current imaging study, researchers measured the subjects' blood transferrin levels. They hoped to determine whether iron availability in the developmentally crucial period of adolescence impacted the organization of the brain later in life.

"Adolescence is a period of high vulnerability to brain insults, and the brain is still very actively developing," Thompson said.

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Why Isn't Human Intelligence Evolving Faster?

Thomas Hills is an associate professor of psychology at Warwick University. Along with Ralph Hertwig from Basel University he recently published a paper entitled "Why Aren't We Smarter Already: Evolutionary Trade-Offs and Cognitive Enhancement".

Why did you embark on this project?

I study the evolution of cognition. There is a growing interest in drug-enhancements for cognitive abilities, such as Ritalin and modafinil. Drugs like these are being used in many different places, like the military and education. So the question is, if these abilities are so great, why don't people already them? Typically, in evolutionary theory, if you want to ask why a fish doesn't swim faster, or why a bird can't see farther, the answer is there are trade-offs. The natural question is: what are the trade-offs for cognition and intelligence?

So you're asking why we haven't evolved to be more intelligent?

Exactly. And the evolutionary answer is that the costs are too high.

Doesn't education increase our intelligence?

Sure. We aren't suggesting that you can't read a book and get smarter; you can. We know from countless studies that if you give kids access to more resources, and you give them a better learning environment, they'll become smarter individuals. Our focus is on the increase in intelligence over evolutionary time, and, specifically, cognitive skills like memory and focus. More memory and focus are not necessarily better. You may not want to be so focused that you don't hear someone yelling "Look out!", or have such a perfect memory that you can instantly relive the pain you've felt at any point in your lifetime.

So, what are the downsides of highly developed cognitive skills?

There are two kinds, and we classify them as "within-domain" and "between-domain" trade-offs. Within-domain refers to cases, for example, where too little or too much focus creates a disadvantage. For instance, if you are pursuing someone you want to marry, and it's not working out, you need to know when to give up. If you are pursuing a particular objective that takes time to accomplish, then you have to know when to carry on.

A between-domain trade-off is what happens in the situation where you get individuals who appear to be exceptional in one domain and simultaneously show deficits in other domains. A classic example is the idiot savant. For example, a person might be able to count hundreds of matches that have been dropped on the floor but can't hold a conversation. Research has shown that you can turn off particular areas of the brain and turn people into these kinds of savants. Now the question is: do you want the skills of the savant?

Even in adult learning, studies by Eleanor Maguire on London taxi-drivers' enhanced spatial awareness noted that it comes with poorer performance in other areas. So they become smarter in one place while losing abilities in other domains. Brains seem to make interesting trade-offs.

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Cerebrospinal Fluid Levels May Indicate Alzheimer's Onset

Searching for a better screen for early Alzheimer's disease, researchers think they have found a marker of change in the brain that precedes the onset of the disease by five to 10 years.

The indicator of trouble to come, they say, is a shift in the levels of specific components of the cerebrospinal fluid (CSF) in the brain and spinal cord. Among patients already diagnosed with mild cognitive impairment, a drop in such levels appears to be a sign of Alzheimer's years before symptoms develop.

The discovery, published in the January issue of Archives of General Psychiatry, could potentially aid in the use of disease-modifying therapies, which are designed to work best if applied when a patient is still in the early stages of disease.

"These markers can identify individuals at high risk for future [Alzheimer's disease] at least five to 10 years before conversion to dementia," study author Dr. Peder Buchhave, of Lund University and Skane University in Sweden, noted in a journal news release. "Hopefully, new therapies that can retard or even halt progression of the disease will soon be available. Together with an early and accurate diagnosis, such therapies could be initiated before neuronal degeneration is too widespread and patients are already demented."
The study results stem from more than nine years of follow-up to prior research that had involved 137 patients diagnosed with mild cognitive impairment, a mental state that often precedes dementia.

Over the course of the study, nearly 54 percent of the patients went on to develop Alzheimer's, while another 16 percent were ultimately diagnosed with different forms of dementia.
Specifically, among those who developed Alzheimer's, the researchers found that key aspects of their cerebrospinal fluid dropped off in the years before. In addition, other fluid properties actually went up.

The study team said that they believe that about nine out of every 10 patients with mild cognitive impairment who experience such fluid shifts will eventually go on to develop Alzheimer's disease.
Commenting on the study, one expert in the United States said that the new research "provides confirmation of the general concept that CSF can predict the progression of mild memory loss to mild dementia."

Dr. Sam Gandy, associate director of the Mount Sinai Alzheimer's Disease Research Center at Mount Sinai School of Medicine in New York City, added that the results of the European study largely echo those of a trial reported by researchers at the U.S. National Institutes of Health in 2010.
He noted that methods of early detection might prove valuable for research into the treatment of Alzheimer's disease.

"Most new Alzheimer's drugs are aimed at reducing amyloid [protein plaque] accumulation, and the general consensus is that these drugs will only work at early or presymptomatic stages of disease," said Gandy, who is also Mount Sinai Chair in Alzheimer's Disease Research. "The new paper strengthens the likelihood that CSF biomarkers can be useful for identifying that population of subjects with early or presymptomatic disease in order to recruit them into trials."

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Study: Bingo Enhances Cognitive Performance in Alzheimers Subjects

Bingo, a popular activity in nursing homes, senior centers and assisted-living facilities, has benefits that extend well beyond socializing. Researchers found high-contrast, large bingo cards boost thinking and playing skills for people with cognitive difficulties and visual perception problems produced by Alzheimer's disease (AD) and Parkinson's disease (PD).

"The general finding of improved performance across healthy and afflicted groups suggests the value of visual support as an easy-to-apply intervention to enhance cognitive performance," researchers from Case Western Reserve University, Boston University and Bridgewater State University wrote.

The findings were reported in the article, "Bingo! Externally supported performance intervention for deficit visual search in normal aging, Parkinson's disease, and Alzheimer's disease," in the journal Aging, Neuropsychology, and Cognition.

As people age, they begin to lose sensitivity to perceive contrasts. It is exacerbated in people with dementia, according to Grover C. Gilmore, a psychologist and dean of the Mandel School of Applied Social Sciences at Case Western Reserve University.

Bingo is often used in nursing homes and senior centers as a social activity, and being socially engaged helps keep the mind healthy.

But little is known about how visual perception problems-common in aging players-affect the way these people think and play, said Gilmore, who has done extensive testing in his Perception Lab at Case Western Reserve.

Researchers tested cards of different sizes, contrasts and visual complexities to find out how visual perception problems impact cognitive functions among the study's participants: 19 younger adults, 14 individuals with probable AD, 13 AD-matched healthy adults, 17 non-demented individuals with Parkinson's disease and 20 PD-matched healthy adults.

When study participants played bingo on computer-generated cards that were manipulated for brightness, size and contrast, the researchers could compare the performance among the different age and health groups.

With some contrast and size changes to the card, researchers reported improvement in performances. For those with mild dementia, they could perform at levels of their healthy peers. Little change was reported for people with more severe dementia.

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