COLLEGE PARK, Md. – A study of older adults at increased risk for Alzheimer's disease shows that moderate physical activity may protect brain health and stave off shrinkage of the hippocampus – the brain region responsible for memory and spatial orientation that is attacked first in Alzheimer's disease. Dr. J. Carson Smith, a kinesiology researcher in the University of Maryland School of Public Health who conducted the study, says that while all of us will lose some brain volume as we age, those with an increased genetic risk for Alzheimer's disease typically show greater hippocampal atrophy over time. The findings are published in the open-access journal Frontiers in Aging Neuroscience.
"The good news is that being physically active may offer protection from the neurodegeneration associated with genetic risk for Alzheimer's disease," Dr. Smith suggests. "We found that physical activity has the potential to preserve the volume of the hippocampus in those with increased risk for Alzheimer's disease, which means we can possibly delay cognitive decline and the onset of dementia symptoms in these individuals. Physical activity interventions may be especially potent and important for this group."
Dr. Smith and colleagues, including Dr. Stephen Rao from the Cleveland Clinic, tracked four groups of healthy older adults ages 65-89, who had normal cognitive abilities, over an 18-month period and measured the volume of their hippocampus (using structural magnetic resonance imaging, or MRI) at the beginning and end of that time period. The groups were classified both for low or high Alzheimer's risk (based on the absence or presence of the apolipoprotein E epsilon 4 allele) and for low or high physical activity levels.
Of all four groups studied, only those at high genetic risk for Alzheimer's who did not exercise experienced a decrease in hippocampal volume (3 percent) over the 18-month period. All other groups, including those at high risk for Alzheimer's but who were physically active, maintained the volume of their hippocampus.
"This is the first study to look at how physical activity may impact the loss of hippocampal volume in people at genetic risk for Alzheimer's disease," says Dr. Kirk Erickson, an associate professor of psychology at the University of Pittsburgh. "There are no other treatments shown to preserve hippocampal volume in those that may develop Alzheimer's disease. This study has tremendous implications for how we may intervene, prior to the development of any dementia symptoms, in older adults who are at increased genetic risk for Alzheimer's disease."
Individuals were classified as high risk for Alzheimer's if a DNA test identified the presence of a genetic marker – having one or both of the apolipoprotein E-epsilon 4 allele (APOE-e4 allele) on chromosome 19 – which increases the risk of developing the disease. Physical activity levels were measured using a standardized survey, with low activity being two or fewer days/week of low intensity activity, and high activity being three or more days/week of moderate to vigorous activity.
"We know that the majority of people who carry the E4 allele will show substantial cognitive decline with age and may develop Alzheimer's disease, but many will not. So, there is reason to believe that there are other genetic and lifestyle factors at work," Dr. Smith says. "Our study provides additional evidence that exercise plays a protective role against cognitive decline and suggests the need for future research to investigate how physical activity may interact with genetics and decrease Alzheimer's risk."
Dr. Smith has previously shown that a walking exercise intervention for patients with mild cognitive decline improved cognitive function by improving the efficiency of brain activity associated with memory. He is planning to conduct a prescribed exercise intervention in a population of healthy older adults with genetic and other risk factors for Alzheimer's disease and to measure the impact on hippocampal volume and brain function.
Milwaukee's Journal Sentinel covers our Alzheimer's study in their July 25th issue. In Men's Health Magazine, Dr. J Carson Smith, the head of our study, talks about reducing your risk of Alzheimer's through exercise.
We are still recruiting people to be involved in our study! If you're interested, fill out our form on our Join Our Studies page or give us a call using the number on our Contact Us page.
New research published in the Proceedings of the National Academy of Sciences shows that adults who exercise at least 40 minutes a week have a larger volume of neurons in the hippocampus. The hippocampus is a structure which is heavily involved in memory. Read more about this study over at NPR.
Another study published by PNAS shows that older adults who exercised at moderate intensity over a year gained volume in their hippocampuses. Read more about this study over at Science Daily.
Participants included individuals who carry a high-risk gene
Physical activity promotes changes in the brain that may protect high-risk individuals against cognitive decline, including development of Alzheimer's disease, according to a new study done at the University of Wisconsin-Milwaukee (UWM).
J. Carson Smith, an assistant professor of health sciences, included in the study both people who carry a high-risk gene for Alzheimer's disease, and other healthy older adults without the gene.
"Our study suggests that if you are at genetic risk for Alzheimer's disease, the benefits of exercise to your brain function might be even greater than for those who do not have that genetic risk," says Smith.
While evidence already shows that physical activity is associated with maintenance of cognitive function across a life span, most of this research has been done with healthy people, without any consideration of their level of risk for Alzheimer's, says Smith.
A team of researchers compared brain activation during memory processing in four separate groups of healthy 65- to 85-years-olds. The level of risk was defined by whether an individual carried the apolipoprotein E-epsilon4 (APOE–ϵ4) allele. Physical activity status was defined by how much and how often the participants reported physical activity (PA). The study divided subjects into Low Risk/Low PA, Low Risk/High PA, High Risk/Low PA and High Risk/High PA.
Functional magnetic resonance imaging (fMRI) was used to measure brain activation of participants while they performed a mental task involving discriminating among famous people. This test is very useful, says Smith, because it engages a wide network called the semantic memory system, with activation occurring in 15 different functional regions of the brain.
"When a person thinks about people – for example, Frank Sinatra or Lady Gaga – that involves several lobes of the brain," explains Smith.
In the study groups of those carrying the gene, individuals who exercised showed greater brain activity in memory-related regions than those who were sedentary.
Perhaps even more intriguing, physically active people with the gene had greater brain activity than those who were physically active but not gene carriers.
There are many physiological reasons why this could be happening, Smith says. "For example, people with this increased activation might be compensating for some underlying neurological event that is involved in cognitive decline.". "Using more areas of their brain may serve as a protective function, even in the face of disease processes."
The study's collaborating institutions include the Cleveland Clinic, Marquette University, Wayne State University and Rosalind Franklin University of Medicine and Science. It was funded by the National Institutes of Health and the National Institute on Aging.
The study will be published in Vol. 54 (January 2011) of the journal NeuroImage, but is now available online.
Smith's current research builds on this study. He and his team are conducting a new study testing the before-and-after effects of a structured exercise program on brain function. The study includes patients diagnosed with mild cognitive impairment or early Alzheimer's disease, as well as a healthy control group.
For more information on this ongoing study, visit http://www.exerciseforbrainhealth.com/.
Exercise and Brain Health: Multi-Modal Imaging and Multi-Modal Activation
Dr. Smith’s research is designed to better understand the effects of exercise on brain function in older adults at risk for Alzheimer’s disease and the effects of concurrently performed exercise on emotional reactivity, threat detection, and attention to emotion. His studies have important implications for cognitive-behavioral treatments that seek to reduce disordered attention toward threatening or unpleasant stimuli. His vision is for his work regarding cognition and memory to merge with questions on emotion processing in order to address the full spectrum of mind-body interactions associated with exercise that promote brain health.
Location: Center for BrainHealth Center for BrainHealth
2200 W. Mockingbird Lane, Dallas, TX 75235
Date: Tuesday, December 7
Time: noon - 1:30 p.m.
R.S.V.P. Gail Cepak at 972.883.3274 or email@example.com
Interactive Effects of Physical Activity and APOE-ε4 on BOLD Semantic Memory Activation in Healthy Eldersled Post
Evidence suggests that physical activity (PA) is associated with the maintenance of cognitive function across the
An article covering some of the latest research on exercise and Alzheimer's disease appeared in Time Magazine recently. Drs. Rao, Smith and more have been collaborating on this subject for a long time. It is wonderful to see the word finally making it's way to the public!
A pdf of the article is below or you can find it on-line at http://wellness.blogs.time.com/2010/09/07/exercise-protects-against-alzheimer/
Dr. Smith was recently interviewed by Mitch Teich on WUWM's Lake Effect radio program regarding his UWM & MCW-CTSI funded project to examine the effects of exercise on brain function in people at risk for Alzheimer's disease.
The interview aired Monday, August 16, at 10am, 89.7FM. It can also be heard anytime thereafter on their website: http://www.wuwm.com/programs/lake_effect/index.php
Dr. Smith appeared with Bonnie Blair on Fox 6 Wake-up talk about current research and the Alzheimer's Association's Memory Walks. For more information on the Memory Walk visit http://www.alz.org/sewi/in_my_community_memorywalk.asp
Here is the link to the interview in case you missed it: http://www.fox6now.com/videobeta/68f3e12b-f072-4c09-a1d1-a7c12876539c/Community/Alzheimers-Memory-Walk