Meditation in patients with mild cognitive impairment (MCI) may slow progression to Alzheimer's disease (AD), new research suggests.
A small, randomized pilot study of adult patients with MCI showed that those who received mindfulness-based stress reduction (MBSR) therapy for 8 weeks had a greater increase in functional connectivity between brain regions related to both MCI and AD than those who received usual care.
These regions included the posterior cingulate cortex, the bilateral medial prefrontal cortex, and the left hippocampus.
In addition, there was "a trend" toward less bilateral hippocampal volume atrophy in the patients who received MBSR compared with the usual-care group.
"This study suggests that an intervention with meditation and yoga may impact the areas of the brain that are most susceptible to developing dementia," lead author Rebecca Erwin Wells, MD, MPH, who was at Beth Israel Deaconess Medical Center (BIDMC) at Harvard Medical School in Boston, Massachusetts, at the time of the study, told Medscape Medical News.
Dr. Wells, who is now an assistant professor in the Department of Neurology at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, noted that although this was a small, preliminary study, she is "very excited" about the findings.
"MBSR is a relatively simple intervention, with very little downside, that may provide real promise for these individuals. If [it] can help delay the symptoms of cognitive decline even a little bit, it can contribute to improved quality of life," said Dr. Wells in a release.
The study is scheduled to be published in the November 27 print issue of Neuroscience Letters.
No Current Treatment
The investigators note that patients with high stress levels are at increased risk of developing MCI and AD, and more than 50% of those with MCI will go on to develop dementia within 5 years.
"Despite the clinical and public health significance of MCI, there are no known therapies preventing progression to dementia," they write.
"While meditation may reduce stress and alter the hippocampus and default mode network (DMN), little is known about its impact in these populations."
Investigators conducted a proof-of-concept study to determine whether MBSR could actually "improve DMN connectivity and reduce hippocampal atrophy" in patients with MCI.
"We were particularly interested in looking at the DMN, the brain system that is engaged when people remember past events or envision the future, and the hippocampus, the part of the brain responsible for emotions, learning, and memory," said Dr. Wells.
She added that they wanted to investigate whether MBSR could attenuate the decline of individuals already experiencing memory problems.
A total of 14 adults older than 54 years with MCI were enrolled between 2010 and 2011 and were randomly assigned to receive either MBSR (n = 9; mean age, 73 years) or usual care (control group; n = 5; mean age, 75 years).
MBSR teaches both mindfulness meditation and yoga. Those who received this arm of treatment underwent 8 weekly 2-hour sessions plus 1 "mindfulness retreat day." In addition, this group was encouraged to spend 30 minutes a day listening to guided audio recordings in their own homes.
All participants also underwent resting state functional magnetic resonance imaging (fMRI) at baseline and at the 8-week mark to measure connectivity changes in areas of the DMN. And MRIs were conducted to measure volume changes in the bilateral hippocampus.
This is "the first study to our knowledge reporting the impact of MBSR on fMRI among patients with MCI," the researchers write.
Increased Connectivity, Less Atrophy
Results showed that, compared with the control group, the MBSR group had a significantly greater increase in functional connectivity between the posterior cingulate cortex (PCC) and the bilateral medial prefrontal cortex and between the PCC and the left hippocampus, as shown by fMRI scans.
Both treatment groups showed bilateral hippocampal atrophy from baseline to the 8-week follow-up, as shown in the MRI scans. Still, although not statistically significant, there was a trend toward less volume atrophy in the MBSR group (P = .07).
No study-related adverse events were reported by either group.
"MBSR may affect the region of the brain most sensitive to MCI and AD," write the investigators.
"If some component of cognitive decline is a function of stress-induced hippocampal changes, then meditation may impact the hippocampus as a stress-reducing technique thereby improving cognitive reserve," they add.
The researchers note that more studies with larger sample sizes and longer follow-up periods are now needed, but they voiced optimism in the findings of their small trial.
"For a condition without a standard treatment and with potential progression to AD, this study provides preliminary evidence that an intervention with limited side effects may be of potential benefit to patients with few other options for improvement," they write.
Dr. Wells noted that researchers at both BIDMC and Wake Forest are continuing to examine these issues.
"I think this study offers a very useful component of therapy for these patients, for several reasons," David Geldmacher, MD, professor and Patsy and Charles Collat Scholar in Neuroscience in the Division of Memory Disorders and Behavioral Neurology at the University of Alabama at Birmingham, told Medscape Medical News.
"First, we know that it's a stressful experience for people with the illness, especially in the early stages. So anything that can help to address that frustration on a symptomatic level is important," said Dr. Geldmacher, who was not involved with the study.
He added that a sense of control and self-direction "is crucial" in this patient population.
"This is an illness where people often feel that someone else is starting to drive the bus and that the disease is starting to take away their rights and privileges. So the ability to do something themselves that may potentially alter the course of their illness is important," he said.
Dr. Geldmacher noted that the physiologic part of this study was also interesting.
"What we don't know in as much detail is whether this intervention could have an ongoing, clinically meaningful effect or not. Obviously there's going to be very little harm, if any, to doing this, and we get the psychological benefits," he said.
"So even if meditation did nothing to the hippocampal structure, it may help to reduce the symptom burden of the illness as a whole."
Can't Hurt, May Help
Thaddeus W. W. Pace, PhD, assistant professor in the College of Nursing and the Department of Psychiatry, College of Medicine, at the University of Arizona in Tuscon, told Medscape Medical News that he had some concerns with the research, including that it was a pilot study and that there were so few participants.
"Even for an imaging study, the number was on the lower side. Also, the overall design could have been a little stronger," he said. For example, he questioned the use of treatment-as-usual for the control condition instead of an active control condition in which participants would also meet with others during the course of the study.
"This would account for the social contact that happens during meditation training. One of the most important challenges we have in our research is how we design the control condition that we're comparing everything to."
Dr. Pace, who was not involved with this study, has conducted previous research examining the effects of meditation on the brain's response to emotional stimuli.
He went on to note, however, that the current study "does have some exciting points."
"The findings themselves are pretty cool, and the outcomes make me want to know more. The big finding was about the [DMN] areas and how they're all working together. And that was quite fascinating," said Dr. Pace.
"The hippocampal volume outcome, even though it was a trend, was also pretty exciting to me, especially because my interest is in stress and health. We know that stress response and inflammation have an impact on chronic illnesses, including Alzheimer's," he explained.
"When the hippocampus atrophies, it may lead to inappropriate regulation of the stress response systems, which can then further the illness process. So it was very interesting that MBSR had an impact, or at least a trend, on hippocampal volume in these folks with MCI."
Overall, Dr. Pace said that it appears that MBSR could be beneficial to this patient population.
"As long as you tell patients that this study's findings are preliminary, I would be comfortable recommending to clinicians that they recommend MBSR to their patients," said Dr. Pace.
"It can't hurt, and as a program, it could only be helpful. If a patient has enough time to devote to it, why not try it? And then clinicians should also keep an eye out for the next-generation study."
The study was funded by several grants and sources, including the National Institutes of Health National Center for Complementary and Alternative Medicine. A full list of funders is available in the original article. The study authors and Dr. Pace have disclosed no relevant financial relationships. Dr. Geldmacher also has disclosed no relevant financial relationships, but he did report that Dr. Wells was a former student of his.
Neurosci Lett. 2013:556;15-19. Abstract
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Cite this: Meditation May Slow Progression to Alzheimer's - Medscape - Nov 26, 2013.