Bewegen en minder ijzer tegen de ziekte van Alzheimer*
Uit twee studies blijkt wat u kunt doen als senior om de ziekte van Alzheimer tegen te gaan: dagelijks bewegen, zorgen voor meer
antioxidanten in de voeding en voor minder
ijzer in uw bloed. In de eerste studie, weliswaar met konijnen blijkt dat het terugbrengen van de hoeveelheid ijzer in uw bloed
het aantal abnormale afbraakproducten aan beta-amyloid als wel de hoeveelheden kluwen van het eiwit tau
duidelijk doet verminderen. Antioxidanten in de voeding kunnen verder de vrije radicalen
schade, mede een oorzaak van de ziekte, verminderen. Uit een tweede studie onder ruim zevenhonderd tachtigers blijkt dat zij die dagelijks het meest bewegen tot wel bijna 3x minder kans hebben op het krijgen van de
ziekte van Alzheimer.
Antioxidant May Disrupt Alzheimer's Disease Process
Alzheimer's disease (AD) is now the sixth leading cause of death among Americans, affecting nearly 1 in 8 people over the age of 65. There is currently no treatment that alters the course of this disease. However, an increasing amount of evidence suggests that changes in the way the body handles iron and other metals like copper and zinc may start years before the onset of AD symptoms. A new study shows that reducing iron levels in blood plasma may protect the brain from changes related to AD.
In the current study a group of investigators from led by Dr. Othman Ghribi, PhD, Associate Professor, Department of Pharmacology, Physiology, and Therapeutics, University of North Dakota School of Medicine and Health Sciences, rabbits were fed a high-cholesterol diet which caused them to accumulate plaques of a small protein called beta-amyloid
(Aẞ). These plaques are toxic to neurons and central to the development of Alzheimer's disease. The rabbits also developed changes in tau protein, which is part of the skeleton of neurons. When this protein becomes heavily phosphorylated, the ability of neurons to conduct electrical signals is disrupted. Following treatment with a drug called deferiprone (an iron chelator), the iron level in the rabbits' blood plasma was reduced and the levels of both beta-amyloid and phosphorylated tau in the brain were returned to normal levels.
Another degenerative process in AD involves the production of reactive oxygen species (ROS) that can damage neurons in the brain. Deferiprone is also thought to suppress this reactive oxygen damage caused by free iron in the bloodstream, however in this study there was no difference in reactive oxygen species in the treated group. It appears that iron in the AD brain is located in the wrong places -- in particular it accumulates to very high levels in the cores of beta-amyloid plaques and is very reactive in this setting.
According to Dr. Ghribi, "Our data show that treatment with the iron chelator deferiprone opposes several pathological events induced by a cholesterol-enriched diet…Deferiprone reduced the generation of Aẞ and lowered levels of tau phosphorylation." While there was no effect on ROS levels, he comments that "It is possible that a higher dose of deferiprone, or combination therapy of deferiprone together with an antioxidant to prevent ROS generation would more-fully protect against the deleterious effects of cholesterol-enriched diet that are relevant to AD pathology."
Noted expert on metals metabolism research on AD Ashley Bush, MD, PhD, Mental Health Research Institute, Melbourne, Australia, adds that "this research highlights the role of metal ions as key modulators for the toxic interactions of risk factors for Alzheimer's disease, in this case cholesterol. Drugs targeting these metal interactions hold promise as disease-modifying agents."
Alzheimer's Disease Risk May Be Reduced At Any Age By Daily Physical Activity
Daily physical activity may reduce the risk of Alzheimer's disease and cognitive decline, even in people over the age of 80, according to a new study by neurological researchers from Rush University Medical Center that will be published in the online issue of Neurology, the medical journal of the American Academy of
Neurology.
"The results of our study indicate that all physical activities including exercise as well as other activities such as cooking, washing the dishes, and cleaning are associated with a reduced risk of Alzheimer's disease," said Dr. Aron S. Buchman, lead author of the study and associate professor of neurological sciences at Rush. "These results provide support for efforts to encourage all types of physical activity even in very old adults who might not be able to participate in formal exercise, but can still benefit from a more active lifestyle."
"This is the first study to use an objective measurement of physical activity in addition to self-reporting," said Dr. Aron S. Buchman, lead author of the study and associate professor of neurological sciences at Rush. "This is important because people may not be able to remember the details correctly."
To measure total daily exercise and non-exercise physical activity, researchers from Rush asked 716 older individuals without dementia with an average age of 82 to wear a device called an actigraph, which monitors activity, on their non-dominant wrist continuously for 10 days.
All exercise and non-exercise physical activity was recorded. Study participants also were given annual cognitive tests during this ongoing study to measure memory and thinking abilities. Participants also self-reported their physical and social activities.
Study participants were individuals from the Rush Memory and Aging Project, an ongoing, longitudinal community study of common chronic conditions of old
age.
Over a mean of 3.5 years of follow-up, 71 participants developed Alzheimer's
disease.
The research found that people in the bottom 10 percent of daily physical activity were more than twice as likely (2.3 times) to develop Alzheimer's disease as people in the top 10 percent of daily
activity.
The study also showed that those individuals in the bottom 10 percent of intensity of physical activity were almost three times (2.8 times) as likely to develop Alzheimer's disease as people in the top percent of the intensity of physical activity.
"Since the actigraph was attached to the wrist, activities like cooking, washing the dishes, playing cards and even moving a wheelchair with a person's arms were beneficial," said Buchman. "These are low-cost, easily accessible and side-effect free activities people can do at any age, including very old age, to possibly prevent
Alzheimer's."
The number of Americans older than 65 years of age will double to 80 million by 2030.
"Our study shows that physical activity, which is an easily modifiable risk factor, is associated with cognitive decline and Alzheimer's disease. This has important public health consequences," said Buchman.
References:
Co-authors of the study from Rush are Patricia Boyle, PhD; Li Yu, PhD; Dr. Raj C. Shah; Robert S. Wilson, PhD; and Dr. David A. Bennett.
The National Institutes of Health, National Institute on Aging, the Illinois Department of Public Health and the Robert C. Borwell Endowment Fund helped fund the study.
Rush University Medical Center (Juni 2012)
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