People With Alzheimer’s Can’t Clear Plaque

Scientists have long been studying beta-amyloid, the sticky protein that builds up in the brains of those with Alzheimer’s disease. Everyone makes beta-amyloid, but in those with Alzheimer’s disease, the protein accumulates to toxic levels, eventually forming clumps in the brain called plaque that may play a part in damaging brain cells critical for thinking and memory.

But does this buildup of plaque occur in Alzheimer’s patients because they make too much beta-amyloid? Or are they unable to clear the sticky protein that naturally forms, the way healthy people do?

Researchers now have a better answer to these questions. It appears that those with Alzheimer’s make perfectly normal amounts of beta-amyloid. The problem is that they are unable to clear it from their brains.

“Clearance is impaired in Alzheimer’s disease,” said Dr. Randall Bateman, assistant professor of neurology at Washington University School of Medicine in St. Louis, who led the study that appeared in the journal Science. The findings could have important implications for diagnosis and treatment of Alzheimer’s, as researchers work to find treatments that can speed clearing of beta-amyloid from the brain.

In the study, researchers compared a group of 12 men and women with early Alzheimer’s disease with 12 healthy peers. Both groups produced beta-amyloid at the same average rate; the protein, at very low levels, seems to play an important role in keeping brain cells from becoming overexcited and firing abnormally. But compared to the healthy controls, those with early Alzheimer’s were 30 percent less able to clear the protein that accumulated in the brain.

The scientists estimate that over 10 years, enough beta-amyloid would accumulate in the brain to form the telltale plaques that damage brain areas crucial for thinking and memory.

“These findings may help point us toward better diagnostic tests and effective therapies. The next question is what is causing the decreased clearance rate,” Dr. Bateman said. “These findings support the idea that impaired beta-amyloid clearance is fundamentally linked to Alzheimer’s disease.”

Pathologists have long recognized beta-amyloid as a component of the plaques that riddle the brains of those with Alzheimer’s. One way the brain clears beta-amyloid is to move it into the spinal fluid, where it is broken down and disposed of. Understanding how this occurs could lead to new drugs and treatments that speed the process, before damage to the brain becomes extensive.

In those with Alzheimer’s, however, this process is impaired. Levels of beta-amyloid rise as the protein gets “stuck” in the brain, meaning that less of the substance moves into the spinal fluid. That’s one reason why studies have found that lower levels of beta-amyloid in the spinal fluid may be an early indicator of Alzheimer’s disease.

Many believe that accumulation of abnormal levels of beta-amyloid in the brain initiates a cascade of events leading to the death of brain cells and ultimately to dementia. In the rare, early-onset forms of Alzheimer’s that are linked to genetic mutations, there is a marked increase in beta-amyloid production. In the more common, late-onset form of Alzheimer’s, the mechanisms leading to increased beta-amyloid levels are not well understood.

Prior studies suggest several possible explanations for the slower clearance of beta-amyloid in late-onset Alzheimer’s. One possibility is that as beta-amyloid accumulates, it acts as a sink for more of the protein, trapping it within the brain. The researchers believe that sorting out these mechanisms is likely to help speed the development of new drugs for the disease.

“Abnormal protein deposits within the brain are a hallmark not only of Alzheimer’s disease, but of many neurological disorders. With knowledge about how these proteins accumulate, we may be able to slow that process and reduce the damage to the brain,” said Roderick Corriveau, Ph.D., a program director at the National Institute of Neurological Disorders and Stroke.

Fisher Scientists Discover New Ways to Rid Cells of Alzheimer Protein, click here for full article.

By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.

Source:

Kwasi G. Mawuenyega, Wendy Sigurdson, Vitaliy Ovod, et al: “Decreased Clearance of CNS Beta-Amyloid in Alzheimer’s Disease.” Science, published online December 9, 2010.

Read More

‘Good’ Cholesterol May Lower Your Alzheimer’s Risk

High levels of high-density lipoprotein, or HDL, the so-called “good” cholesterol, appear to protect against Alzheimer’s disease, according to a new report. The findings come from a study of older adults living in New York City who were followed for about four years.

Previous studies have shown that high levels of HDL seem to protect against heart attacks and strokes. Hence the name “good” cholesterol. The new findings, publishing in the Archives of Neurology, from the American Medical Association, suggest HDL has protective effects, not just for the heart, but for the brain as well.

In the study, researchers at Columbia University’s Taub Institute for Research on Alzheimer’s and the Aging Brain studied 1,130 seniors living in northern Manhattan. None had Alzheimer’s at the start of the study. All were given blood tests to assess their cholesterol levels, including levels of HDL.

During the follow-up period, 101 of the participants developed Alzheimer’s; their average age was 83. Men and women who had the highest HDL levels, measuring 55 milligrams per deciliter of blood or higher, developed 60 percent fewer cases of Alzheimer’s disease than those with the lowest HDL levels, of 38 milligrams or less. The protective effect persisted even after the researchers considered such Alzheimer’s risk factors as age, education levels and genes that predispose to the disease.

Professional medical guidelines recommend that men raise HDL levels that are under 40 milligrams per deciliter, and that women increase HDL numbers under 50 milligrams. An HDL of 60 milligrams or higher is considered optimal.

Regular exercise, and especially aerobic activities like walking, dancing or running, are thought to boost levels of “good” HDL cholesterol. Other studies have shown that regular exercise may likewise reduce the risk of developing Alzheimer’s later in life. Exercise also improves cardiovascular function, including blood flow to the brain. In addition, a heart-healthy Mediterranean diet, rich in fish, nuts and healthy oils like olive oil, is also recommended to keep the brain healthy into old age.

By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.

Source:

Christiane Reitz; Ming-Xin Tang; Nicole Schupf; Jennifer J. Manly; Richard Mayeux; José A. Luchsinger: “Association of Higher Levels of High-Density Lipoprotein Cholesterol in Elderly Individuals and Lower Risk of Late-Onset Alzheimer Disease.” Archives of Neurology, Vol. 67 (No. 12), pages 1491-1497.

Read More

What to Expect When You’re Caregiving

Anyone who has cared for a loved one with Alzheimer’s knows just how stressful and unpredictable the experience can be. Yet most people who care for a family member with the disease have little preparation or experience when they begin their caregiving journey. A new interactive tool from Caring.com, a Web site dedicated to caregiving concerns, aims to ease the process by providing support and advice geared towards the progressive downward course of Alzheimer’s and other types of dementia.

The free program, called Steps & Stages, is an interactive guide that dispenses caregiver guidance customized to the particular stage of Alzheimer’s they are facing. “Caring.com’s Steps & Stages provides clear actions steps tailored to your loved one’s stage of Alzheimer’s,” notes Betsey Odell, Vice President of The Fisher Center for Alzheimer’s Research Foundation. “The action steps guide family caregivers right now, without having to wait days or weeks to get helpful advice.”

At the Web site, at http://www.caring.com/steps-stages/alzheimers, the caregiver first enters the patient’s name, age and family relationship. He or she then checks off a series of boxes about specific symptoms, such as repeating questions or stories, forgetting to fill prescriptions, an inability to remember who just visited, confusing long-ago memories with recent events, and identifying friends and family members.

The program also asks follow-up questions about how often memory lapses and other problems occur, and how well a loved one can handle personal care, like dressing or washing. Mood issues like anger and aggression, a common problem as Alzheimer’s progresses, are also addressed.

The tool then ranks patients according to their stage of illness, be it early, moderate or severe. Each of these stages is, in turn, divided into early, mid and late sub-stages.

A caregiver guide provides specific tips on “What to do” about specific problems, like managing personal care, repeating questions, forgetting appointments or emotional outbursts. Tips on prescription medication errors, for example, include suggestions like setting up automatic refills, arranging for home delivery, using day-of-the-week dispensers, making pill-taking part of the daily routine, and bringing in all medications to doctor’s appointments for a regular “brown bag” review.

Caregivers also have the option of receiving a free e-mail newsletter about what to expect, measures to take, and tips on coping and caring for someone with Alzheimer’s. The tool also includes a community feature called Stage Groups, where caregivers dealing with similar problems can talk to one another and share tips and support.

As new symptoms of Alzheimer’s arise, caregivers can update their Care Guide, and the information and advice changes dynamically. The program was modeled on another popular Web site the creators had developed, BabyCenter.com, which is geared toward new parents.

Research conducted by Caring.com shows that nearly 50 percent of families caring for a loved one with Alzheimer’s do not know what stage of the illness their family member is in. This uncertainty makes it very difficult to make important decisions on a daily basis and properly care for a mother, father or other close friend or relative with Alzheimer’s. For most of the more than 1,100 caregivers the company surveyed, a diagnosis of Alzheimer’s came a year or more after memory loss and other symptoms first appeared.

“Caring.com’s Steps & Stages is geared toward my mom’s stage of Alzheimer’s, so I can get information specific to what I’m experiencing,” said one of the site’s users, Martha Huggart from Raymond, Mississippi. “The tips are very helpful, both in helping me know how to take care of my mom and in reminding me to take care of myself,” she added.

Medical advisors on the site include Leslie Kernisan, M.D., MPH, a practicing geriatrician and clinical instructor at the University of California, San Francisco, geriatrics division, and Ken Robbins, M.D., a geriatric psychiatrist and clinical professor of psychiatry at the University of Wisconsin in Madison. Other experts who provided review include Lisa Gwyther, MSW, associate professor in psychiatry at Duke University Medical Center and coauthor of “The Alzheimer’s Action Plan: A Family Guide.”

The Steps & Stages tool is available on Caring.com at http://www.caring.com/steps-stages/alzheimers, along with the Stage Assessment, Custom Care Guide and weekly e-mail newsletter signup. Additional community and content features are planned in the coming months.

By Alzinfo.org, The Alzheimer’s Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.

Read More

Counseling and Support Benefits Alzheimer’s Caregivers Worldwide
A first-of-its-kind international trial of caregivers has shown that counseling and support services can benefit those who are caring for a loved one with Alzheimer’s disease when that person is also taking a medication for the disease.
Read More

Writing May Ease the Stress of Caring for Alzheimer’s
Expressing thoughts and feelings may help caregivers to make sense of a difficult situation.
Read More