October 14, 2010
Walking about six miles a week appears to protect against brain shrinkage in old age, which in turn helps stem the onset of memory problems and cognitive decline, new research reveals.
“We have always been in search of the drug or the magic pill to help treat brain disorders,” noted Kirk I. Erickson, an assistant professor of psychology at the University of Pittsburgh and the study’s lead author. “But really what we are after may be, at least partially, even simpler than that. Just by walking regularly, and so maintaining a little bit of moderate physical activity, you can reduce your likelihood of developing Alzheimer’s disease and [can] spare brain tissue.”
A report on the research, which was supported by the U.S. National Institute on Aging, is published online Oct. 13 in Neurology.
Erickson and his colleagues began tracking the physical activity and cognitive (or thinking) patterns of nearly 300 adults in 1989. At the start, all participants were in good cognitive health, they averaged 78 years old and about two-thirds were women. The researchers charted how many blocks each person walked in a week.
Nine years later, they were given a high-resolution MRI scan to measure brain size. All were deemed to be “cognitively normal.”
But four years after that, testing showed that a little more than one-third of the participants had developed mild cognitive impairment or dementia.
By correlating cognitive health, brain scans and walking patterns, the research team found that being more physically active appeared to marginally lower the risk for developing cognitive impairment.
But more specifically, they concluded that the more someone walks, the more gray matter tissue the person will have a decade or more down the road in regions of the brain — namely the hippocampus, the inferior frontal gyrus and the supplementary motor area — that are central to cognition.
And among the more physically active participants who had retained more gray matter a decade out, the chances of developing cognitive impairment were cut in half, the study found.
However, the researchers stressed that the relationship between walking and gray matter volume appears to apply only to people who regularly walk relatively long distances that equal about six to nine miles a week.
Walking more than the six- to nine-mile range, however, did not have cognitive benefit, the study found.
“That’s because the size of our brain regions can only be so large,” Erickson said, adding that the opposite isn’t true. “So with no exercise, there can be significant deterioration and decay with age.”
However, he added, “what we often tend to think of as an inevitable component or characteristic of aging — memory decline and brain decay — is clearly not inevitable. There’s plenty of evidence now, and this study is part of that, that shows that we can retain our brain tissue and retain our memories well into late adulthood by maintaining an active and engaged lifestyle.”
Dr. Steven V. Pacia, chief of neurology at Lenox Hill Hospital in New York City, described the study’s finding as both “intriguing” and an “undoubtedly positive message to send to the public.”
“My first reaction to studies like this is that only in America do we have to prove to people that it’s good to walk,” he said with a chuckle.
“But it stands to reason that being active as we age is going to have a beneficial effect on the brain, just as being inactive is going to have a negative impact,” Pacia noted. “Because the brain lives in the environment of the body.”
But there may be a catch. “This is just an observational study,” Pacia noted. “And while we may assume that the relationship between the brain and activity is a prevention-of-atrophy issue — just like it is with muscle and bone — this study doesn’t actually prove that. We don’t yet know enough about the use-it-or-lose-it notion with respect to brain and exercise. So we do need more research to look at that.”
October 9th, 2010
By: Jonathan Benson
New research out of Indiana University adds to the growing list of harmful side effects caused by chemotherapy. According to scientists, the chemical cancer treatment destroys gray matter in the brain associated with cognitive function and memory.
Published in the journal Breast Cancer Research and Treatment, the study is the first of its kind to use brain imaging scans to verify the negative effects of chemotherapy on the brain. However, previous studies have already found that chemotherapy damages cognitive function, providing the basis for the popular term used to describe this condition known as “chemobrain”.
“These analyses…suggest an anatomic basis for the cognitive complaints and performance changes seen in patients,” explained Andrew Saykin, Psy.D., director of the Indiana University Center for Neuroimaging and researchers at the IU Simon Cancer Center. “Memory and executive functions like multi-tasking and processing speed are the most typically affected functions and these are handled by the brain regions where we detected gray matter changes.”
Although the effects can be temporary, gray matter destruction due to chemotherapy is often permanent. Some people become so impaired following chemotherapy that they are never able to return to work, that is if they survive the treatment at all.
According to The McGill Cancer Center in Canada, 91 percent of oncologists surveyed indicated that “all chemotherapy programs are unacceptable to them and their family members.” Instead of helping to treat cancer, chemotherapy destroys the only thing that even has a chance at preventing it: the immune system.
For an interesting look at natural alternatives to chemotherapy, check out this great interview with Dr. Albert Sanchez, the “Father of Poly-MVA” — a non-toxic alternative to chemotherapy.
September 10, 2010
By: Kate Kelland
Daily tablets of large doses of B vitamins can halve the rate of brain shrinkage in elderly people with memory problems and may slow their progression toward dementia, data from a British trial showed on Wednesday,
Scientists from Oxford University said their two-year clinical trial was the largest to date into the effect of B vitamins on so-called “mild cognitive impairment” — a major risk factor for Alzheimer’s disease and other forms of dementia.
Experts commenting on the findings said they were important and called for larger, longer full-scale clinical trials to see if the safety and effectiveness of B vitamins in the prevention of neurodegenerative conditions could be confirmed.
“This is a very dramatic and striking result. It’s much more than we could have predicted,” said David Smith of Oxford’s department of pharmacology, who co-led the trial.
“It is our hope that this simple and safe treatment will delay development of Alzheimer’s in many people who suffer from mild memory problems.”
Mild cognitive impairment (MCI) affects around 16 percent of people aged over 70 worldwide and is characterized by slight problems with memory loss, language or other mental functions.
MCI does not usually interfere with daily life, but around 50 percent of people diagnosed with it go on to develop the far more severe Alzheimer’s disease within five years. Alzheimer’s is a mind-wasting disease for which there are few treatments and no cure, and which affects 26 million people around the world.
Smith and colleagues conducted a two-year trial with 168 volunteers with MCI who were given either a vitamin pill containing very high doses of folic acid, vitamin B6 and vitamin B12, or a placebo dummy pill.
These B vitamins are known to control levels of an amino acid called homocysteine in the blood, and high blood levels of homocysteine are linked to an increased risk of developing Alzheimer’s disease.
Helga Refsum, who also worked on the trial, stressed that vitamins were given in extremely high doses.
“This is a drug, not a vitamin intervention,” she said.
The pills, called “TrioBe Plus” contained around 300 times the recommended daily intake of B12, four times daily advised folate levels and 15 times the recommended amount of B6.
Brain scans were taken at the beginning and the end of the trial to monitor the rate of brain shrinkage, or atrophy.
The results, published in the Public Library of Science (PLoS) One journal, showed that on average the brains of those taking the vitamin treatment shrank at a rate of 0.76 percent a year, while those taking the dummy pill had an average brain shrinkage of 1.08 percent.
People who had the highest levels of homocysteine at the start of the trial benefited the most from the treatment, with their brains shrinking at half the rate of those on the placebo.
Although the trial was not designed to measure cognitive ability, the researchers found those people who had lowest rates of shrinkage had the highest scores in mental tests.
Commenting on the study, Paul Matthews, a professor of clinical neurology at Imperial College London said that although the vitamins used are generally safe and inexpensive, the study “should not drive an immediate change in clinical practice”
“Instead, it sets out important questions for further study and gives new confidence that effective treatments modifying the course of some dementias may be in sight,” he said.
May 21, 2010
Drugs to treat anxiety and sleep disorders are still being prescribed for extended periods to British Columbian patients – and increasingly so for baby boomers – despite warnings against long-term use, according to a University of British Columbia study.
Published online in the journal Health Policy, the study by researchers at UBC’s Centre for Health Services and Policy Research (CHSPR) is the first of its kind to examine the use of benzodiazepines such as Xanax and Ativan for an entire population over time. It’s also the first to pinpoint the socio-economic characteristics associated with long-term users of such drugs.
Results show that seniors and low-income earners are more likely to be long-term users of benzodiazepines, with rates remaining steady over a 10-year period. Meanwhile, use among the middle-aged population has increased. Harms associated with long-term use (more than 100 days in a year) can include dependence and tolerance, cognitive impairment, and increased risks of falls in the elderly.
“Given the potential for dependence and harms associated with these drugs, they are recommended to be used sparingly for short periods,” says Colleen Cunningham, CHSPR researcher and lead author of the study. “However, our study suggests that a significant number of British Columbians – especially the elderly who suffer greater health risks from falls – are using them for long periods.”
February 22, 2010
Volunteers who slept for 90 minutes during the day did better at cognitive tests than those who were kept awake.
Results of the University of California at Berkeley study involving 39 healthy adults were presented at a conference.
A UK-based sleep expert said it was hard to separate the pure “memory boosting” effects of sleep from those of simply being less tired.
The wealth of study into the science of sleep in recent years has so far failed to come up with conclusive evidence as to the value of a quick “siesta” during the day.
The latest study suggests that the brain may need sleep to process short-term memories, creating “space” for new facts to be learned.
In their experiment, 39 healthy adults were given a hard learning task in the morning – with broadly similar results, before half of them were sent for their siesta.
When the tests were repeated, the nappers outperformed those who had carried on without sleep.
Checks on brain electrical activity suggested that this process might be happening in a sleep phase between deep sleep, and dreaming sleep, called stage 2 non-rapid eye movement sleep, when fact-based memories are moved from “temporary storage” in the brain’s hippocampus to another area called the pre-frontal cortex.
Dr Matthew Walker, who led the study, reported at the AAAS conference in San Diego, said: “Sleep not only rights the wrong of prolonged wakefulness, but, at a neurocognitive level, it moves you beyond where you were before you took a nap.
“It’s as though the e-mail inbox in your hippocampus is full, and, until you sleep and clear out all those fact e-mails, you’re not going to receive any more mail.
“It’s just going to bounce until you sleep and move it into another folder.”
However, Professor Derk-Jan Dijk, the director of the Surrey Sleep Research Centre, said that there was no clear evidence that daytime napping offered a distinct advantage over sleeping just once over 24 hours.
“The sleep-wake cycle is not as rigid as we might think – we have the capability to sleep in different ways.”
He said that while the brain effect reported in the study might be spotted in a laboratory setting, the picture became more clouded in the “real world”.
“The size of these effects are much more difficult to assess – if I have to learn something, for example, it’s easier to do this when I’m feeling awake and alert than when I’m sleepy.”
January 22, 2010
The report, which was published in the Proceedings of the National Academy of Sciences, found mice which exercised performed better on memory tests.
These mice also grew more new cells in a part of the brain linked to memory than those which did not exercise.
The authors believe the new brain cells were behind the improvement in cognitive performance.
The aim of the study, which was carried out by scientists from the Department of Experimental Psychology at the University of Cambridge and researchers at the National Institute on Aging in Baltimore, was to find out why exercise might improve brain function.
Previous research had suggested that exercise helps mental performance in both people and animals. Studies had also shown that exercise increases the number of new brain cells in rodents.
The new finding in this study is that mice which exercise are better able to distinguish between memories of similar things. The authors believe this is explained by the additional brain cells generated by exercise.
The study was conducted on two groups of mice over a period of 105 days. The mice were trained to touch a box on a computer screen to get food pellets.
One group were then allowed unlimited access to an exercise wheel. They ran over 20km (12 miles) a day on average. The control group were not able to exercise.
Both groups were then repeatedly shown two boxes on a screen, one of which provided a treat when it was touched.
The mice learned which box released the treat, and then the boxes were moved around. First the boxes were moved close together, which made it harder for the mice to remember which one to touch to get the food.
The exercising mice did better on this task than the non-exercising mice.
The task was then made easier by placing the boxes further apart so that they seemed more distinct. This time there was no difference in the performance of the exercising and non-exercising mice.
“Keeping similar memories distinct is an important part of having a good memory” says the senior author of the study, Timothy Bussey from Cambridge University.
“It is this aspect of memory that is improved by exercise, our study shows.
“The human equivalent might be remembering which car parking space you have used on two different days in the previous week. It becomes difficult to distinguish memories when events are similar.”
By the end of the experiment, the animals which exercised had more than twice as many new brain cells as those that did not.
These cells were in the hippocampus, an area of the brain which is important in memory and learning.
The Cambridge team believes the results of their study may well extrapolate to humans, a view shared by another researcher who studies the impact of exercise on memory.
Stan Colcombe, from Bangor University, said: “Their data strongly suggest that new neurons created after exercise can play a role in improving cognitive function, which likely has direct implications for human research into the effects of exercise on neurocognition.”
He described the research as “a very elegant experiment” which “made a valuable contribution in understanding the effects of exercise on brain health and function”.