Tuesday, November 13, 2012

Avoiding Dementia Part I

A dear friend, only 85 years old, healthy and physically and mentally active (golf, tennis, bridge) has developed serious signs of mental decline. This has alarmed me sufficiently to review what recent research says about this:

Regular Physical Activity Reduces Risk of Dementia in Older People

In a new study published in the American Heart Association journal Stroke, older, non-disabled people who regularly engaged in physical activity reduced their risk of vascular-related dementia by 40 percent and cognitive impairment of any etiology by 60 percent.

The protective effect of regular physical activity remained regardless of age, education, changes in the brain's white matter and even previous history of stroke or diabetes, researchers said.

The findings are based on a prospective multinational European study that included yearly comprehensive cognitive assessments for three years. The results are part of increasing evidence that regular physical activity promotes brain health, researchers said.

"We strongly suggest physical activity of moderate intensity at least 30 minutes three times a week to prevent cognitive impairment," said Ana Verdelho, M.D., lead author of the study and a neuroscience researcher at the University of Lisbon, Santa Maria Hospital in Portugal. "This is particularly important for people with vascular risk factors such as hypertension, stroke or diabetes."

The analysis included 639 people in their 60s and 70s; 55 percent were women and almost 64 percent said they were active at least 30 minutes a day three times a week. The activity included gym classes, walking and biking.

The American Heart Association recommends at least 150 minutes of moderate exercise every week or 75 minutes of vigorous exercise for optimal health.

Researchers performed magnetic resonance imaging (MRI) tests at the beginning and end of the study to gauge white matter changes in the brain, an indicator of possible cognitive decline.

"Damage of the cerebral white matter is implicated in cognitive problems including depression, walking difficulties and urinary complaints," Verdelho said. "White matter changes are very common in older people and mainly associated with vascular risk factors like hypertension and stroke."

Throughout the study, researchers asked participants in phone interviews and clinical visits about depression, quality of life and performing everyday activities.

At the end of the follow-up, 90 patients had dementia, including 54 with vascular dementia in which impaired blood flow to the brain causes cognitive decline, and 34 patients met criteria for Alzheimer's disease. Another 147 patients developed cognitive impairment, but not dementia.

Aspirin may slow the decline in mental capacity among elderly patients


A daily dose of acetylsalicylic acid equivalent to a fourth of an aspirin may slow the decline in intellectual capacity among elderly individuals with high cardiovascular risk. This is shown in a study by Sahlgrenska Academy, University of Gothenburg, Sweden.

Researchers at Sahlgrenska Academy, University of Gothenburg, over a five year period studied how intellectual capacity changes among 681 elderly women (70 to 92 years) with heightened risk of suffering from a heart attack, vascular spasm or stroke.

Of the 681 women, 129 received a low daily dose of acetylsalicylic acid, equivalent to a fourth of an aspirin, to prevent heart disease. The Gothenburg study shows that acetylsalicylic acid also slowed decline in brain capacity among the elderly women.

In the study, published in British Medical Journal Open, the women underwent various tests to measure their physical health and intellectual capacity, such as language and memory tests.

"At the end of the five year examination period mental capacity had declined among all the women and the portion that suffered from dementia was equally large in the entire group. However, the decline in brain capacity was significantly less and occurred at a slower pace among the women who received acetylsalicylic acid," says Silke Kern, researcher at Sahlgrenska Academy.

Vitamin C and beta-carotene might protect against dementia

Cocoa may enhance brain function

Eating cocoa flavanols daily may improve mild cognitive impairment, according to new research in the American Heart Association's journal Hypertension.

Each year, more than six percent of people aged 70 years or older develop mild cognitive impairment, a condition involving memory loss that can progress to dementia and Alzheimer's disease.

Flavanols can be found in tea, grapes, red wine, apples and cocoa products and have been associated with a decreased risk of dementia. They may act on the brain structure and function directly by protecting neurons from injury, improving metabolism and their interaction with the molecular structure responsible for memory researchers said. Indirectly, flavanols may help by improving brain blood flow.

Researchers found

: • Scores significantly improved in the ability to relate visual stimuli to motor responses, working memory, task-switching and verbal memory for those drinking the high and intermediate flavanol drinks.
• Participants drinking daily higher levels of flavanol drinks had significantly higher overall cognitive scores than those participants drinking lower-levels.


High blood caffeine levels linked to avoidance of Alzheimer's disease

Those cups of coffee that you drink every day to keep alert appear to have an extra perk – especially if you're an older adult. A recent study monitoring the memory and thinking processes of people older than 65 found that all those with higher blood caffeine levels avoided the onset of Alzheimer's disease in the two-to-four years of study follow-up. Moreover, coffee appeared to be the major or only source of caffeine for these individuals.

Researchers from the University of South Florida (www.usf.edu) and the University of Miami (www.miami.edu)say the case control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset. Their findings will appear in the online version of an article to be published June 5 in the Journal of Alzheimer's Disease, published by IOS Press (http://health.usf.edu/nocms/publicaffairs/now/pdfs/JAD111781.pdf). The collaborative study involved 124 people, ages 65 to 88, in Tampa and Miami.

"These intriguing results suggest that older adults with mild memory impairment who drink moderate levels of coffee -- about 3 cups a day -- will not convert to Alzheimer's disease -- or at least will experience a substantial delay before converting to Alzheimer's," said study lead author Dr. Chuanhai Cao, a neuroscientist at the USF College of Pharmacy (http://health.usf.edu/nocms/pharmacy/) and the USF Health Byrd Alzheimer's Institute (http://health.usf.edu/nocms/byrd/). "The results from this study, along with our earlier studies in Alzheimer's mice, are very consistent in indicating that moderate daily caffeine/coffee intake throughout adulthood should appreciably protect against Alzheimer's disease later in life."

The study shows this protection probably occurs even in older people with early signs of the disease, called mild cognitive impairment, or MCI. Patients with MCI already experience some short-term memory loss and initial Alzheimer's pathology in their brains. Each year, about 15 percent of MCI patients progress to full-blown Alzheimer's disease. The researchers focused on study participants with MCI, because many were destined to develop Alzheimer's within a few years.

Blood caffeine levels at the study's onset were substantially lower (51 percent less) in participants diagnosed with MCI who progressed to dementia during the two-to-four year follow-up than in those whose mild cognitive impairment remained stable over the same period.

No one with MCI who later developed Alzheimer's had initial blood caffeine levels above a critical level of 1200 ng/ml – equivalent to drinking several cups of coffee a few hours before the blood sample was drawn. In contrast, many with stable MCI had blood caffeine levels higher than this critical level.

"We found that 100 percent of the MCI patients with plasma caffeine levels above the critical level experienced no conversion to Alzheimer's disease during the two-to-four year follow-up period," said study co-author Dr. Gary Arendash.

The researchers believe higher blood caffeine levels indicate habitually higher caffeine intake, most probably through coffee. Caffeinated coffee appeared to be the main, if not exclusive, source of caffeine in the memory-protected MCI patients, because they had the same profile of blood immune markers as Alzheimer's mice given caffeinated coffee. Alzheimer's mice given caffeine alone or decaffeinated coffee had a very different immune marker profile.

Since 2006, USF's Dr. Cao and Dr. Arendash have published several studies investigating the effects of caffeine/coffee administered to Alzheimer's mice. Most recently, they reported that caffeine interacts with a yet unidentified component of coffee to boost blood levels of a critical growth factor that seems to fight off the Alzheimer's disease process.

"We are not saying that moderate coffee consumption will completely protect people from Alzheimer's disease," Dr. Cao cautioned. "However, we firmly believe that moderate coffee consumption can appreciably reduce your risk of Alzheimer's or delay its onset."

Alzheimer's pathology is a process in which plaques and tangles accumulate in the brain, killing nerve cells, destroying neural connections, and ultimately leading to progressive and irreversible memory loss. Since the neurodegenerative disease starts one or two decades before cognitive decline becomes apparent, the study authors point out, any intervention to cut the risk of Alzheimer's should ideally begin that far in advance of symptoms.

"Moderate daily consumption of caffeinated coffee appears to be the best dietary option for long-term protection against Alzheimer's memory loss," Dr. Arendash said. "Coffee is inexpensive, readily available, easily gets into the brain, and has few side-effects for most of us. Moreover, our studies show that caffeine and coffee appear to directly attack the Alzheimer's disease process."

In addition to Alzheimer's disease, moderate caffeine/coffee intake appears to reduce the risk of several other diseases of aging, including Parkinson's disease, stroke, Type II diabetes, and breast cancer. However, supporting studies for these benefits have all been observational (uncontrolled), and controlled clinical trials are needed to definitively demonstrate therapeutic value.

A study tracking the health and coffee consumption of more than 400,000 older adults for 13 years, and published earlier this year in the New England Journal of Medicine, found that coffee drinkers reduced their risk of dying from heart disease, lung disease, pneumonia, stroke, diabetes, infections, and even injuries and accidents.

With new Alzheimer's diagnostic guidelines encompassing the full continuum of the disease, approximately 10 million Americans now fall within one of three developmental stages of Alzheimer's disease -- Alzheimer's disease brain pathology only, MCI, or diagnosed Alzheimer's disease. That number is expected to climb even higher as the baby-boomer generation continues to enter older age, unless an effective and proven preventive measure is identified.

"If we could conduct a large cohort study to look into the mechanisms of how and why coffee and caffeine can delay or prevent Alzheimer's disease, it might result in billions of dollars in savings each year in addition to improved quality of life," Dr. Cao said.

Light-to-moderate alcohol consumption, in comparison with abstinence, was associated with approximately 35-45% lower risk of cognitive decline or dementia


Alzheimer's disease (AD) and other types of dementia are most common in the very elderly, and are associated with huge health costs. With a rapidly ageing population throughout the world, factors that affect the risk of cognitive decline and dementia are of great importance. A review paper by Kim JW et al published in Psychiatry Investig 2012;9:8-16 on the association between alcohol consumption and cognition in the elderly provides an excellent summary of the potential ways in which alcohol may affect cognitive function and the risk of dementia, both adversely and favourably as alcohol may have both a neuro toxic and neuro protective effect, depending on the dose and drinking pattern. Longitudinal and brain imaging studies in the elderly show that excessive alcohol consumption may increase the risk of cognitive dysfunction and dementia, but regular low to moderate alcohol intake may protect against cognitive decline and dementia and provide cardiovascular benefits.

Studies published from 1971 to 2011 related to alcohol and cognition in the elderly were reviewed using a PubMed search. At present, there are no proven agents to prevent cognitive decline or dementia, although a number of prospective epidemiologic studies have shown a lower risk of such conditions among light to moderate drinkers in comparison with non-drinkers. Other studies have found that beneficial effects are seen only among certain sub-groups of subjects. A recent meta-analysis by Peters et al of subjects over the age of 65 in longitudinal studies concluded that light-to-moderate alcohol consumption, in comparison with abstinence, was associated with approximately 35-45% lower risk of cognitive decline or dementia.

This paper provides a summary of what is known about the mechanisms by which alcohol consumption, especially heavy drinking, can be neurotoxic, and how light-to-moderate drinking may help protect against cognitive decline and dementia. The authors state that their intent is to determine if there is an "optimal pattern of drinking" that may protect the elderly against such conditions.

At present, the mechanisms by which the moderate intake of wine and other alcoholic beverages reduces the risk of cardiovascular diseases are much better defined than they are for cognition. Forum members agree with the authors that further research is needed to evaluate a potential role that alcohol may play in reducing the risk of dementia.

Forum members also agree that, at present, the specific mechanisms of such putative protection are not well defined, and it would be premature to recommend light-to-moderate drinking for reducing the risk of dementia. On the other hand, current biomedical data supports the concept that regular, moderate intake of ethanol is not simply less dangerous for cognitive function, but is positively protective. This is the same conclusion reached by epidemiologic studies."



With fat: What's good or bad for the heart, may be the same for the brain


It has been known for years that eating too many foods containing "bad" fats, such as saturated fats or trans fats, isn't healthy for your heart. However, according to new research from Brigham and Women's Hospital (BWH), one "bad" fat—saturated fat—was found to be associated with worse overall cognitive function and memory in women over time. By contrast, a "good" fat—mono-unsaturated fat was associated with better overall cognitive function and memory.

This study is published online by Annals of Neurology, a journal of the American Neurological Association and Child Neurology Society, on May 18, 2012.

The research team analyzed data from the Women's Health Study—originally a cohort of nearly 40,000 women, 45 years and older. The researchers focused on data from a subset of 6,000 women, all over the age of 65. The women participated in three cognitive function tests, which were spaced out every two years for an average testing span of four years. These women filled out very detailed food frequency surveys at the start of the Women's Health Study, prior to the cognitive testing.

"When looking at changes in cognitive function, what we found is that the total amount of fat intake did not really matter, but the type of fat did," explained Olivia Okereke, MD, MS, BWH Department of Psychiatry.

Women who consumed the highest amounts of saturated fat, which can come from animal fats such as red meat and butter, compared to those who consumed the lowest amounts, had worse overall cognition and memory over the four years of testing. Women who ate the most of the monounsaturated fats, which can be found in olive oil, had better patterns of cognitive scores over time.

"Our findings have significant public health implications," said Okereke. "Substituting in the good fat in place of the bad fat is a fairly simple dietary modification that could help prevent decline in memory."

Okereke notes that strategies to prevent cognitive decline in older people are particularly important. Even subtle declines in cognitive functioning can lead to higher risk of developing more serious problems, like dementia and Alzheimer disease.

Eating Fish, Chicken, Nuts May Lower Risk of Alzheimer's Disease


A new study suggests that eating foods that contain omega-3 fatty acids, such as fish, chicken, salad dressing and nuts, may be associated with lower blood levels of a protein related to Alzheimer's disease and memory problems.

Resistance-training, can alter the trajectory of cognitive decline


Cognitive decline is a pressing global health care issue. Worldwide, one case of dementia is detected every seven seconds. Mild cognitive impairment is a well recognized risk factor for dementia, and represents a critical window of opportunity for intervening and altering the trajectory of cognitive decline in seniors.

A new study by researchers at the Centre for Hip Health and Mobility at Vancouver Coastal Health and the University of British Columbia shows that implementing a seniors' exercise program, specifically one using resistance-training, can alter the trajectory of decline. Perhaps most importantly, the program improved the executive cognitive process of selective attention and conflict resolution as well as associative memory, which are robust predictors of conversion from mild cognitive impairment to dementia.

The research led by Teresa Liu-Ambrose, principal investigator with the Centre for Hip Health and Mobility and the Brain Research Centre at VCH and UBC, and co-investigators from the Department of Psychology and Division of Geriatric Medicine at UBC, and Department of Psychology, University of Iowa, was published today in the Archives of Internal Medicine.

Over the course of six months, the study team followed 86 senior women with probable mild cognitive impairment. The randomized controlled trial is the first to compare the efficacy of both resistance and aerobic training to improve executive cognitive functions - such as attention, memory, problem solving and decision making - necessary for independent living. The trial also assessed the effect of both types of exercise on associative memory performance and corresponding functional brain plasticity.

Both types of exercise were performed twice weekly for six months. Participants were measured with a series of cognitive tests and brain plasticity was assessed using functional MRI. The results showed resistance-training significantly improved executive cognitive functions, associative memory performance, and functional brain plasticity. In contrast to previous studies in healthy older adults, aerobic training did not demonstrate any significant effect for cognitive and brain plasticity.

"There is much debate as to whether cognitive function can be improved once there is noticeable impairment," says Liu-Ambrose, "What our results show is that resistance training can indeed improve both your cognitive performance and your brain function. What is key is that it will improve two processes that are highly sensitive to the effects of aging and neurodegeneration: executive function and associative memory -- often impaired in early stages of Alzheimer's disease."

This work builds on the same researcher team's Brain Power Study, published in the January 2010 issue of Archives of Internal Medicine and July 2011 issue of Neurobiology of Aging, which demonstrated that 12 months of once-weekly or twice-weekly progressive strength training improved executive cognitive function and functional brain plasticity in healthy women aged 65- to 75- years- old and provided lasting benefits.

Coinciding with the study, the team has developed and launched an informative YouTube video http://www.youtube.com/watch?v=vG6sJm2d4oc of the resistance training exercises used in the study.

"Exercise is attractive as an prevention strategy for dementia as it is universally accessible and cost-effective," says Liu-Ambrose, who is who is also an assistant professor, in the Department of Physical Therapy at UBC and a Michael Smith Foundation for Health Research and CIHR New Investigator scholar. "By developing this YouTube video we can help translate our findings directly to the senior population and fitness instructors who are working with them."

No comments: