Posts Tagged "Alzheimer’s disease"

Up to two-thirds of Alzheimer’s cases worldwide may stem from any of nine conditions that often result from lifestyle choices, a broad research review suggests. The findings were published online Aug. 20 in the Journal of Neurology, Neurosurgery & Psychiatry.

Jin-Tai Yu, M.D., Ph.D., an associate specialist in neurology at the University of California, San Francisco, and colleagues reviewed the findings of 323 studies completed between 1968 and 2014. Collectively, the studies involved more than 5,000 patients and looked at 93 conditions with the potential to affect Alzheimer’s risk. The team set out to determine which factors appeared to offer some protection against developing Alzheimer’s.

The strongest evidence suggested that coffee, vitamins C and E, folate, nonsteroidal anti-inflammatory drugs, statins, antihypertensive medications, and estrogen supplementation all appeared to reduce Alzheimer’s risk. Patients battling several serious health conditions also seemed to see their risk fall, including those with arthritis, heart disease, metabolic syndrome, and/or cancer. Those who were light or moderate drinkers of alcohol similarly saw their Alzheimer’s risk dip, alongside current smokers (apart from those of Asian descent), those struggling with stress, and seniors with high body mass index.

By contrast, a complex statistical analysis enabled the research team to zero in on the nine factors that appeared to elevate Alzheimer’s risk among 66 percent of those who ultimately get the disease. Those include high body mass index in midlife; carotid artery disease; hypertension; depression; frailty; being poorly educated; having high levels of homocysteine; and (specifically among those of Asian descent) being a smoker and/or having type 2 diabetes. “The current evidence from our study showed that individuals would benefit from [addressing] the related potentially modifiable risk factors,” Yu told HealthDay. Yu is also senior editor of the Journal of Alzheimer’s Disease.

Source: MPR

Scientists have discovered a molecule that can interrupt an important stage in the development of Alzheimer’s disease. The molecule sticks to faulty proteins and stops them forming toxic clusters in the brain.

The UK and Swedish researchers suggest their finding will help the discovery of drugs that could halt Alzheimer’s disease progression.

They write about their discovery and its implications in the journal Nature Structural & Molecular Biology.

Lead author Dr. Samuel Cohen – a research fellow at St John’s College in Cambridge, UK – says with studies like theirs, we are beginning to reap the rewards of the extensive work that has been done to increase our understanding of the microscopic processes involved in the development of Alzheimer’s. He adds:

“Our study shows, for the first time, one of these critical processes being specifically inhibited, and reveals that by doing so we can prevent the toxic effects of protein aggregation that are associated with this terrible condition.”

Many functions in cells are carried out by carefully folded proteins. Folding is an energy-efficient way of ensuring distant parts of the protein molecule that need to interact are near each other. Some of these structures are complex and need the help of housekeeping molecules called “chaperones.”

A key step in the development of Alzheimer’s and other degenerative diseases is the accumulation or “nucleation” of misfolded proteins – known as amyloid fibrils – that do not disperse or dissolve away but form toxic clusters and help the disease spread in the brain.

The molecule that the international team has discovered is a chaperone called Brichos that sticks to threads of amyloid fibrils and stops them coming into contact with each other, thus breaking the toxic chain reaction.

Source: Medical News Today

People with moderate-to-severe vitamin D deficiencies are significantly more likely to develop Alzheimer’s disease or other forms of dementia than those who have an adequate supply of the vitamin in their body, a new study has found.

Researchers, led by David J. Llewellyn at the University of Exeter Medical School, found that adults who suffered from a moderate deficiency of vitamin D had a 53 percent higher risk of some form of dementia, while the risk increased 125 percent in those with severe deficiencies. People moderately deficient in vitamin D were 69 percent more likely to develop Alzheimer’s-caused dementia, while those severely deficient raised the risk to 122 percent.

The team discovered what appear to be clear threshold levels for brain health using standard medical measurements of concentration in the blood. The risk of dementia appears to rise for people with vitamin D blood levels below 25 nanomoles per liter, while vitamin D levels above 50 nanomoles appear to be good levels for brain health.

Llewellyn said that although the international team of researchers expected to find a link between vitamin D deficiency and dementia, the strong correlation between the two was surprising. He said further study was necessary to determine whether consuming oily fish or vitamin D supplements might prevent Alzheimer’s disease.

Alzheimer’s disease is the leading form of dementia, affecting more than 5 million people in the United States. That number is expected to reach 16 million by 2050 as the population ages.

Vitamin D, which helps the body use calcium, is created when skin is exposed to sunshine. Milk is often fortified with the vitamin, and it is also found in fatty fish and other foods.

Researchers in the Exeter study noted that laboratory experiments have shown that vitamin D may play a role in ridding cells of beta-amyloid plaques, an abnormality that distinguishes Alzheimer’s.

“It seems to be that vitamin D was actually helping to break down and take away those protein abnormalities,” Llewellyn said Wednesday in an interview.

The study, funded in part by the Alzheimer’s Association, appeared Wednesday in Neurology, the medical journal of the American Academy of Neurology.

Source: Washington Post

Sleep disturbances such as apnea may increase the risk of Alzheimer’s disease, while moderate exercise in middle age and mentally stimulating games, such as crossword puzzles, may prevent the onset of the dementia-causing disease, according to research to be presented Monday.

The findings — which are to be introduced during the six-day Alzheimer’s Association International Conference in Copenhagen — bolster previous studies that suggest sleep plays a critical role in the aging brain’s health, perhaps by allowing the body to cleanse itself of Alzheimer’s-related compounds during downtime. The studies also add to a growing body of literature that suggests keeping the brain busy keeps it healthy.

The battle against Alzheimer’s disease has become more urgent for the United States and other developing nations as their populations turn increasingly gray. The disease is the leading cause of dementia in older people and afflicts more than 5 million Americans. At its current pace, the number is expected to soar to 16 million people by 2050.

In 2012, the United States adopted a national plan to combat the disease and the Group of Eight nations last year adopted a goal of providing better treatment and prevention by 2025.

Erin Heintz, a spokeswoman for the Alzheimer’s Association, said U.S. government funding to combat the disease now stands at about $500 million a year. To reach its 2025 goal, th e United States should be spending $2 billion a year, she said.

The sleep study, conducted by University of California at San Francisco researchers on a large sample of veterans, found that those with diagnosed sleep disorders such as apnea or insomnia were 30 percent more likely to suffer dementia than veterans without such problems. Veterans who suffered from sleep problems and post-traumatic stress disorder (PTSD) had an 80 percent greater risk.

“I would say that this is another important study showing this link between sleep and subsequent diagnosis of dementia,” Kristine Yaffe, a psychiatry professor at UCSF who heads its Dementia Epidemiology Research Group, said in a telephone interview. She said her study’s findings benefited from having such a large sample of participants: Researchers used eight years of records on 200,000 veterans, most of whom were male and 55 or older.

It is well known that people afflicted with Alzheimer’s suffer from sleep disorders, Yaffe said, but further research is necessary to determine whether sleep disturbance heightens the risk of getting dementia or is a symptom.

In a separate study, researchers at the Wisconsin Alzheimer’s Institute and the Wisconsin Alzheimer’s Disease Research Center wanted to find out whether middle-aged people who engage in mentally stimulating activities might reduce their risk of cognitive impairment and dementia. Forty percent of the subject group carried the gene linked to Alzheimer’s and 74 percent had a parent with the illness, two factors known to increase the risk of getting the disease.

The researchers studied 329 participants — 69 percent of whom were women, whose mean age was about 60 — to find out how often the participants read books, visited museums, played games such as checkers or worked on puzzles.

The subjects also underwent a battery of tests, including MRI brain scans to measure the volume of those regions commonly afflicted by Alzheimer’s.

For purposes of the study, researchers focused on the group’s game-playing habits to see if the frequency of playing games was related to better brain and cognitive health.

Stephanie Schultz, lead author of the study, said that although more research is necessary to know for sure, the findings suggest that stimulating the brain with ordinary diversions such as crossword puzzles may help some people preserve brain tissue and cognitive functions that are vulnerable to dementia. Those who reported a higher frequency of playing games also had greater brain volume in regions affected by Alzheimer’s, such as the hippocampus.

“The more they play these types of games, the better it is for … brain health,” she said.

One reason could be that game-playing involves more complicated processes across multiple regions of the brain, compared with more passive forms of mental engagement, the researchers said.

“It’s very clear it’s a different quality of mental engagement when you’re playing games of skill than when you’re reading a book,” said Ozioma Okonkwo, an assistant professor of medicine at the University of Wisconsin School of Medicine and senior author of the study. “To win a card game, you have to judge, you have to plan, you have to do something, you have to remember what the last player played.”

Okonkwo said the results were exciting particularly because they held true for people with a family history of Alzheimer’s and a genetic disposition to the disease.

“These individuals already have two strikes against them,” he said.

Similarly, a three-year study of people with mild cognitive impairment by researchers at the Mayo Clinic Study of Aging suggests that moderate physical exercise in middle age could decrease the risk that their cognitive deficits progress to dementia. The study looked at the timing of regular exercise — undertaken either in midlife between the ages of 50 and 65, or later in life, from age 70 and up — and its relationship to the onset of dementia in a group of 280 elderly people. Their median age was 81.

Oddly, however, the association did not hold for people who engaged in light or vigorous exercise in middle age or for any level of physical activity later in life.

On a similarly counterintuitive note, another study suggested that high blood pressure among people at least 90 years old — “the oldest old” — may protect against cognitive impairment. Researchers at the University of California at Irvine said that although hypertension is believed to increase the risk of Alzheimer’s and dementia for middle-aged people, the risk may shift with time.

Their study, which examined 625 people who are 90 or older, found that people who were diagnosed with high blood pressure between the ages of 80 and 89 had a significantly lower risk of dementia. People with hypertension after the age of 90 had an even lower risk, the researchers said.

(Source: Washington Post)

Women are at a much higher risk for developing Alzheimer’s disease than men, and the condition poses an even greater risk for elderly women than breast cancer, a new report finds.

According to the latest Alzheimer’s Association 2014 Alzheimer’s Disease Facts and Figures report, women have a 1 in 6 estimated lifetime risk of developing the disease at age 65, while the risk for men is nearly 1 in 11. Additionally, women in their 60s are about twice as likely to develop Alzheimer’s as they are to develop breast cancer.
These differences in gender are further reflected by the fact that there are 2.5 times as many women than men providing 24-hour care for someone living with Alzheimer’s.
Acting as an “on-duty” caregiver for someone living with Alzheimer’s creates a strain that leads to feelings of isolation and depression, as well as the need to take a leave of absence or give up working entirely. While performing caregiving duties, 20 percent of women went from working full-time to working part-time, compared to 3 percent of men.

“[W]e know that women are the epicenter of Alzheimer’s disease, representing majority of both people with the disease and Alzheimer’s caregivers. Alzheimer’s Association Facts and Figures examines the impact of this unbalanced burden,” said Angela Geiger, chief strategy officer of the Alzheimer’s Association.
Alzheimer’s disease is currently the sixth leading cause of death in the United States and affects more than 5 million Americans – including 3.2 million women. Adding to that, 15.5 million caregivers provide 17.7 billion hours of unpaid care. Dementia caregiving resulted in an estimated $9.3 billion in increased health care costs for caregivers in 2013.

Given these statistics, the Alzheimer’s Association is calling for a greater investment in research of the disease.
“Well-deserved investments in breast cancer and other leading causes of death such as heart disease, stroke and HIV/AIDS have resulted in substantial decreases in death. Comparable investments are now needed to realize the same success with Alzheimer’s in preventing and treating the disease,” Geiger said.

The Alzheimer’s Association points out that there is still a lack of understanding about the disease – a form of dementia that causes problems with memory, thinking and behavior.

“Despite being the nation’s biggest health threat, Alzheimer’s disease is still largely misunderstood. Everyone with a brain — male or female, family history or not — is at risk for Alzheimer’s,” Geiger said. “Age is the greatest risk factor for Alzheimer’s, and America is aging. As a nation, we must band together to protect our greatest asset, our brains.”

Source: Fox News

Browning meat in the oven, grill or frying pan produces chemicals which may increase the risk of developing dementia, US researchers suggest. Advanced glycation end (AGE) products have been linked to diseases such as type-2 diabetes. Mice fed a high-AGEs diet had a build-up of dangerous proteins in the brain and impaired cognitive function.

Experts said the results were “compelling” but did not provide “definitive answers”. AGEs are formed when proteins or fats react with sugar. This can happen naturally and during the cooking process.

Researchers at the Icahn school of medicine at Mount Sinai, in New York, tested the effect of AGEs on mice and people. The animal experiments, published in Proceedings of the National Academy of Sciences, showed that a diet rich in AGEs affects the chemistry of the brain. It leads to a build-up of defective beta amyloid protein – a hallmark of Alzheimer’s disease. The mice eating a low-AGEs diet were able to prevent the production of damaged amyloid.

The mice performed less well in physical and thinking tasks after their AGEs-rich diet. A short-term analysis of people over 60 suggested a link between high levels of AGEs in the blood and cognitive decline.

The study concluded: “We report that age-related dementia may be causally linked to high levels of food advanced glycation end products. Importantly, reduction of food-derived AGEs is feasible and may provide an effective treatment strategy.”

Derek Hill, a professor of medical imaging sciences at University College London, commented: “The results are compelling. Because cures for Alzheimer’s disease remain a distant hope, efforts to prevent it are extremely important, but this study should be seen as encouraging further work, rather than as providing definitive answers.

“But it is grounds for optimism – this paper adds to the body of evidence suggesting that using preventative strategies might reduce the prevalence of Alzheimer’s disease and other dementias in society and that could have very positive impact on us all.”

Dr Simon Ridley, from the charity Alzheimer’s Research UK, said: “Diabetes has previously been linked to an increased risk of dementia, and this small study provides some new insight into some of the possible molecular processes that may link the two conditions.It’s important to note that the people in this study did not have dementia. This subject has so far not been well studied in people, and we don’t yet know whether the amount of AGEs in our diet might affect our risk of dementia.”

Source: BBC

A study conducted by scientists at the University of Rochester Medical Center shows that, during sleep, the brain flushes out cellular waste. Though the study was conducted on mouse brains, the lead researcher said that the plumbing system also exists in dogs and baboons, and it’s logical to think that the human brain also clears away toxic substances. This study may provide new clues to treat Alzheimer’s disease and other disorders, in which toxic substances build up.

When we sleep, our brains get rid of gunk that builds up while we’re awake. The finding may mean that for people with dementia and other mind disorders, “sleep would perhaps be even more important in slowing the progression of further damage,” Dr. Clete Kushida, medical director of the Stanford Sleep Medicine Center, said in an email. Kushida did not participate in the study, which appeared in the journal Science.

People who don’t get enough shut-eye have trouble learning and making decisions, and are slower to react. But despite decades of research, scientists can’t agree on the basic purpose of sleep. Reasons range from processing memory, saving energy to regulating the body.

The latest work, led by scientists at the University of Rochester Medical Center, adds fresh evidence to a long-standing view: When we close our eyes, our brains go on a cleaning spree. The team previously found a plumbing network in mouse brains that flushes out cellular waste. For the new study, the scientists injected the brains of mice with beta-amyloid, a substance that builds up in Alzheimer’s disease, and followed its movement. They determined that it was removed faster from the brains of sleeping mice than awake mice.

The team also noticed that brain cells tend to shrink during sleep, which widens the space between the cells. This allows waste to pass through that space more easily.Though the work involved mouse brains, lead researcher Dr. Maiken Nedergaard said this plumbing system also exists in dogs and baboons, and it’s logical to think that the human brain also clears away toxic substances. Nedergaard said the next step is to look for the process in human brains.

In an accompanying editorial, neuroscientist Suzana Herculano-Houzel of the Federal University of Rio de Janeiro said scientists have recently taken a heightened interest in the spaces between brain cells, where junk is flushed out.

It’s becoming clearer that “sleep is likely to be a brain state in which several important housekeeping functions take place,” she said in an email.

The study was funded by the National Institute of Neurological Disorders and Stroke. In a statement, program director Jim Koenig said the finding could lead to new approaches for treating a range of brain diseases.

Source: USA Today

The herpes virus that produces cold sores during times of stress now has been linked to cognitive impairment throughout life, according to a new University of Michigan study that for the first time shows an impact on children ages 12-16. Researchers at the U-M School of Public Health study examined the association between two latent herpes viruses—Herpes Simplex Virus Type 1 and cytomegalovirus (CMV)—and cognitive impairment among individuals across three age groups: 6-16, 20-59, and 60 and older. The researchers used data from the National Health and Nutrition Examination Survey. HSV-1 is the oral herpes virus. Previous research has linked it with neurological disorders associated with aging, including Alzheimer’s disease and dementia, but few studies have examined whether these pathogens may influence cognition beginning early in life. “This study is a first step in establishing an association between these viruses and cognition across a range of ages in the U.S. population,” said Allison Aiello, associate professor of epidemiology at the U-M School of Public Health.

Source: University of Michigan