Little Evidence That Diet, Lifestyle Cuts Alzheimer's Risk

Numerous studies have attempted to link specific behaviors and health conditions to the onset of Alzheimer's disease, but scientists still can't say for sure that anything you do or don't do will prevent the brain disorder, according to a new U.S. review of recent research. The U.S. National Institutes of Health convened a conference last spring to analyze 18 studies of potential risk factors, such as poor eating habits, chronic illness, smoking or little exercise, and development of Alzheimer's disease. "Although we are not dismissing the potential or important role that these major risk factors might play in the development of Alzheimer's disease, at this time, with what we have currently, we cannot confirm any risk associations," said study lead author Dr. Martha L. Daviglus, a professor of preventive medicine and medicine at the Northwestern University Feinberg School of Medicine in Chicago.

"So we need to conduct more research, if we want to have the evidence in hand," she added. The study, which summarizes the NIH conference results, is published in the May 9 online edition and September print issue of the Archives of Neurology. For now, older age is the leading known risk factor for Alzheimer's disease, the study noted. A gene variation is also tied to increased risk, it said. An estimated 5.3 million Americans struggle with Alzheimer's, a figure projected to grow as the country's Baby Boomer population ages, the authors said. The disease is responsible for between 60 and 80 percent of dementia cases. "What we're talking about here is something that is going to affect so many Americans in the years to come," said one expert, Catherine Roe, an instructor in neurology at Washington University School of Medicine in St. Louis. "In fact, there's going to be an explosion in the next 50 years, because everyone is living longer in general," she said.

The studies included in the NIH research review were conducted between 1984 and 2009 in English. Participants were at least 50 years old and living in developed countries. Some of the studies looked into dietary influences, such as folic acid intake, Mediterranean diet and nutritional supplements. Others looked for a link between health problems, such as diabetes or high cholesterol, and Alzheimer's. Still others explored levels of physical activity or alcohol consumption and risk of Alzheimer's disease. The NIH team found that, as a whole, the studies were "compromised by methodological limitations" that undercut the ability to draw a firm association between any particular behavioral habit and/or health condition and Alzheimer's.

Can Hormone Therapy or the Pill Prevent Brain Aneurysms?

Taking birth control pills or hormone replacement therapy could protect women against brain aneurysms later in life, a new study suggests, although one neurologist questioned the quality of the research. Cerebral aneurysms occur when a blood vessel in the brain weakens and balloons out, potentially leading to a hemorrhagic (or bleeding) stroke if the vessel bursts. These types of aneurysms are more common in women than men, possibly because lower levels of female hormones after menopause play a role in their development, the study authors noted.

Brain aneurysms are more common after the age of 40 and are most likely to burst when people are in their 50s. In the study, Dr. Michael Chen, of Rush University Medical Center, and colleagues interviewed 60 women who had experienced brain aneurysms and asked about their use of birth control pills and hormone replacement therapy, and compared their answers to those from a group of almost 4,700 other women in the general U.S. public. The women who had brain aneurysms were significantly less likely to have taken birth control pills or received hormone replacement therapy, and were also more likely to have entered menopause earlier, according to the report published online May 4 in the Journal of NeuroInterventional Surgery.

Previous research has suggested that taking birth control pills lowers the risk of hemorrhagic (bleeding) stroke in later life. However, women who either begin menstruating at an early age, don't have children, or both, face a higher risk. Because estrogen is important for the repair and maintenance of blood vessel walls, a drop in the levels of the female hormone is believed to be the reason for the increased risk to the structure of these vessels, the study authors noted in background information about the research. However, commenting on the study, neurologist Dr. Cathy Sila said the research is flawed and its conclusions overstated.

Stroke Hospitalizations Up in Teens, Young Adults

Older Americans are suffering fewer strokes, but new government research shows that stroke hospitalizations are sharply rising among children and younger adults, especially for men under 35. Although the study doesn't explore the reasons for the trend, experts point to the obesity epidemic, increasing rates of diabetes and high blood pressure as likely culprits. Recreational drugs may play a role as well, they added. "Young people should see their doctor for regular checkups," said Dr. Brett Kissela, a professor of neurology at the University of Cincinnati Neuroscience Institute, who has conducted previous research on strokes but was not involved with this study.

Routine check-ups can help control risk factors for stroke, such as high blood pressure, he explained. Dr. Mary George, a researcher with the U.S. Centers for Disease Control and Prevention, is scheduled to report the findings Wednesday at the International Stroke Conference in Los Angeles. Experts note that research presented at meetings typically has not been subjected to the same scrutiny as studies published in peer-reviewed medical journals. For the study, CDC researchers examined hospitalization data for the period from 1994 to 2007 from the Nationwide Inpatient Sample, identifying patients with a primary diagnosis of ischemic stroke.

Ischemic stroke, which occurs when a blood clot or clogged artery blocks the blood supply to the brain, is more common than hemorrhagic stroke, the result of a ruptured blood vessel. The increases and decreases in stroke rates varied by gender and age group, the researchers found. Among males aged 15 to 34, the rate surged by nearly 53 percent. Among females in that age group, it increased 17 percent. Strokes soared 36 percent in boys aged 5 to 14 and 31 percent in girls of the same age. Men between 35 and 44 years old had a 47 percent increase in stroke incidence. For women in that age range, stroke incidence rose 36 percent.

Electrical Stimulation of the Brain May Spark Insight

Electrical stimulation of the brain can bring a flash of insight that can help people solve new, difficult problems, research suggests. Investigators in Australia found that volunteers who received electrical stimulation of the brain's anterior temporal lobes were three times more likely to be able to figure out a challenging, unfamiliar problem than participants in a control group.

Many people have difficulty achieving creative leaps needed to solve new problems because they tend to stick to strategies and insights that have been successful before, study authors Richard Chi and Allan Snyder, from the Center for the Mind at the University of Sydney, explained in a news release from the Public Library of Science.The use of "transcranial direct current stimulation" temporarily increases or decreases the activity of populations of brain cells, the study authors said.

This safe, noninvasive technique can be used to manipulate the competition between the left and right hemispheres of the brain by inhibiting and/or activating certain networks, they explained. According to Chi and Snyder, the right anterior temporal lobe is associated with insight or finding new meaning, and the inhibition of activity in the left anterior temporal lobe can lead to thinking that is less likely to be influenced by preconceptions. However, the authors noted that more research is needed.

Brisk Walks May Boost Memory in Older Adults

Older adults who took a brisk walk three times a week did better on memory tests and increased the size of their hippocampus, a portion of the brain involved with memory formation, researchers report. The findings suggest that loss of brain volume in old age can be delayed, and may even be reversible. Brain shrinkage is associated with memory impairment in the elderly. "We can change the brain in older adults," said lead study author Kirk Erickson, an assistant professor of psychology at the University of Pittsburgh.

"It's amazing that a one-year period of moderate exercise isn't just slowing down the atrophy, it's actually reversing it." For their the study, researchers from the University of Pittsburgh, University of Illinois, Rice University and Ohio State University divided 120 sedentary adults in their mid to late 60s, on average, into two groups: one group walked around a track for 40 minutes of aerobic exercise, three days a week, while the other group did stretching. Both groups performed better on a test of spatial memory. Spatial memory helps us to remember things like driving directions or where we left our keys.

But the groups differed in one important way. MRI brain scans showed that after a year on the exercise program, the aerobic exercise group's hippocampus was about 2 percent bigger than it was when they started, the equivalent to a reversal in age-related brain shrinkage of about one to two years, the researchers said. Those in the stretching group had a decrease of hippocampal volume of about 1.4 percent, the investigators found. Those who showed the greatest improvements in memory also showed the greatest increases in hippocampal volume, according to the study, published online Jan. 31 in the Proceedings of the National Academy of Sciences.

Odds of Quitting Smoking May Be Clear on Scans

Brain scans can predict a smoker's chances of being able to quit, according to a new study. It included 28 heavy smokers recruited from a smoking cessation program. Functional MRI was used to monitor the participants' brain activity as they watched television ads meant to help people quit smoking. The researchers contacted the participants one month later and found that they were smoking an average of five cigarettes a day, compared with an average of 21 a day at the start of the study.

But there was considerable variation in how successful individual participants were in reducing their smoking. The researchers found that a reaction in an area of the brain, called the medial prefrontal cortex, while watching the quit-smoking ads was linked to reductions in smoking during the month after the brain scan. Previous research by the same team suggested that activity in the prefrontal cortex is predictive of behavior change.

In the new study, published in the current issue of Health Psychology, "we targeted smokers who were already taking action to quit, and we found that neural activity can predict behavior change, above and beyond people's own assessment of how likely they are to succeed," study author Emily Falk, director of the Communication Neuroscience Laboratory at the University of Michigan Institute for Social Research and Department of Communication Studies, said in a university news release.

Epilepsy Found to Be More Common in U.S. Than Thought

A new study suggests that one of every 26 people in the United States will develop epilepsy at some point in their life. That's a higher rate than previously believed and, experts say, highlights the need for more funding and attention to the condition. "This study is an important analysis of the potential number of patients of epilepsy in the United States," said Dr. Joseph I. Sirven, the chairman-elect of the Epilepsy Foundation's professional advisory board and a professor and chairman of neurology at the Mayo Clinic in Scottsdale, Ariz.

Sirven, who was not involved in the study, noted that it makes two important points:

* Older adults are more at risk for developing epilepsy.

* A greater number of people will develop epilepsy during their lifetime than thought.

"The study suggests up to 12 million Americans will develop epilepsy, which is a greater number than expected," Sirven said. "Moreover, this is a conservative estimate and not the worst case scenario as the lifetime risk would be higher in more urban areas. Clearly, more attention needs to be paid to this condition." The findings are published in the Jan. 4 issue of Neurology. For the study, Dale C. Hesdorffer, an associate professor of clinical epidemiology at Sergievsky Center at Columbia University Medical Center in New York City, and her research colleagues looked for the likelihood of developing epilepsy among residents of Rochester, Minn., between 1960 and 1979.

Gene Research Brings Insight Into Deadly Childhood Brain Tumor

U.S. scientists have unraveled the genetic code for the most common type of brain cancer in children. Gene sequencing reveals that this tumor, medulloblastoma, or MB, possesses far fewer genetic abnormalities than comparable adult tumors. The discovery that MB has five to 10 times fewer mutations than solid adult tumors could further attempts to understand what triggers the cancer and which treatment is most effective.

"The good news here is that for the first time now we've identified the broken genetic pieces in a pediatric cancer, and found that with MD there are only a few broken parts," said lead author Dr. Victor E. Velculescu, associate professor with the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University in Baltimore. "And that means it's potentially easier to intervene and to stop it," he said, likening the cancer to a train that's speeding out of control.

Velculescu and his colleagues, who report their findings in the Dec. 16 online issue of Science, say this is the first time genetic decoding has been applied to a non-adult cancer. Each year this cancer strikes about 1 in every 200,000 children younger than 15 years old. Before migrating through the patient's central nervous system, MBs begin in the cerebellum portion of the brain that is responsible for controlling balance and complicated motor function.

Brain Scan Might Someday Spot Autism

A type of brain imaging that measures the circuitry of brain connections may someday be used to diagnose autism, new research suggests. Researchers at McLean Hospital in Boston and the University of Utah used MRIs to analyze the microscopic fiber structures that make up the brain circuitry in 30 males aged 8 to 26 with high-functioning autism and 30 males without autism. Males with autism showed differences in the white matter circuitry in two regions of the brain's temporal lobe: the superior temporal gyrus and the temporal stem. Those areas are involved with language, emotion and social skills, according to the researchers.

Based on the deviations in brain circuitry, researchers could distinguish with 94 percent accuracy those who had autism and those who didn't. Currently, there is no biological test for autism. Instead, diagnosis is done through a lengthy examination involving questions about the child's behavior, language and social functioning. The MRI test could change that, though the study authors cautioned that the results are preliminary and need to be confirmed with larger numbers of patients.

"Our study pinpoints disruptions in the circuitry in a brain region that has been known for a long time to be responsible for language, social and emotional functioning, which are the major deficits in autism," said lead author Nicholas Lange, director of the Neurostatistics Laboratory at McLean Hospital and an associate professor of psychiatry at Harvard Medical School. "If we can get to the physical basis of the potential sources of those deficits, we can better understand how exactly it's happening and what we can do to develop more effective treatments."

High Cholesterol in Middle Age May Not Raise Dementia Risk for Women

For years, doctors have been saying that keeping your cholesterol levels in check as you age is good for your brain as well as your heart, but a new study suggests the connection between cholesterol and dementia later in life isn't quite so clear-cut. After more than 1,400 Swedish women followed for 32 years, Johns Hopkins researchers found that those with high cholesterol at mid-life were at no greater risk of developing Alzheimer's and other types of dementia than women with lower levels. In addition, the women whose cholesterol levels decreased the most from middle to older age were 2.5 times more likely to develop dementia than those whose levels increased or stayed the same.

Both cell and animal studies have suggested that high cholesterol contributes to Alzheimer's disease, the researchers noted, but they stressed that the relationship between cholesterol and dementia may vary over a lifetime. "Our findings highlight how risk factors can change over the course of a person's life span," said Michelle M. Mielke, an assistant professor of psychiatry at Hopkins and lead author of the study, which was published online Nov. 10 in the journal Neurology. "My biggest worry is that people will look at these results and decide that cholesterol doesn't matter, but that's not what we're saying," Mielke added.

"We know that high cholesterol is a very strong risk factor for cardiovascular disease and still needs to be treated with diet, exercise and possibly medication." Mielke added that it was unclear why a decline in cholesterol levels in old age was linked to a higher risk of dementia, but said it might be an early part of the disease process. "As people start to develop symptoms, they often forget to eat and start losing weight, and that may be why their cholesterol goes down." For the study, Mielke and her colleagues examined data from the Prospective Population Study of Women, which began in 1968 and consisted of 1,462 Swedish women between the ages of 38 and 60.

More Kids Who Play Basketball Suffering Head Injuries

Children's basketball may be getting rougher or the kids may be bigger, but either way the number of head injuries is soaring, researchers report. "Although the total number of injuries decreased during the study period, the number of traumatic brain injuries increased by 70 percent," said study author Lara McKenzie, of the Center for Injury Research and Policy at Nationwide Children's Hospital in Columbus, Ohio. "These injuries are exceedingly high in this popular sport," she added. "This is cause for alarm." McKenzie thinks the increased size of players is one factor in the increase in concussions. Another is that the game has become more competitive, she said. Why total injuries have gone down by 20 percent over the 11 years covered by the study is not clear, McKenzie added.

"We don't want to discourage kids from physical activity. We don't want to discourage kids from playing basketball, either," she said. "But we need to recognize that there are some inherent risks in any activity." McKenzie added that the problem of traumatic brain injury needs to be addressed. "Maybe we need to do more education of coaches, athletes and parents to recognize the signs of concussion and help to prevent them," she said. The findings are published in the Sept. 13 online edition of the journal Pediatrics. For the study, McKenzie's team used data from 1997 to 2007 from the U.S. Consumer Product Safety Commission's National Electronic Injury Surveillance System to estimate the number of children injured while playing basketball.

Over the study period, the researchers found an estimated 4,128,852 children were treated in emergency rooms for injuries sustained while playing the sport. That's 375,350 every year. While the total number of injuries went down over the study period, traumatic brain injuries increased 70 percent, the researchers found. The most common other injuries were sprains in the legs 30.3 percent, particularly of the ankle. Boys were more likely to suffer cuts, fractures and dislocations, while girls were more likely to suffer concussions and knee injuries. Children 15 to 19 years of age were three times more likely to injure their knees and ankles, while younger children, aged 5 to 10, were more likely to suffer concussions, fractures and dislocations, the study found.

Recurring Stroke Risk Higher for Some Hispanics

Mexican-American stroke survivors with a heart rhythm disorder called atrial fibrillation are more than twice as likely to suffer a second stroke compared to white patients, a new study finds. It also found that even though these strokes are more likely to be severe among Mexican-Americans, they don't have a greater risk of death after a second stroke. In people with atrial fibrillation, the heart's upper chambers (atria) beat irregularly and don't pump blood effectively. This can cause blood to pool within the atria, which can lead to the formation of blood clots that can break off and travel to the brain, causing a stroke.

This study included 88 Mexican-Americans and 148 white stroke survivors with atrial fibrillation. Compared to the white patients, the Mexican-American stroke survivors were younger, less likely to have completed 12 years of education, more likely to have diabetes, and less likely to have a primary care physician. Over a median follow-up of 427.5 days, 19 Mexican-Americans and 14 whites had at least one recurrent stroke. All but one of those cases involved an ischemic stroke, which is caused by blocked blood flow to the brain. One Mexican-American patient suffered a hemorrhagic stroke, which is bleeding in the brain.

The study appears in the current issue of the journal Stroke. "Based on some of our prior research, we were not necessarily surprised by the higher recurrence rate in Mexican-Americans with atrial fibrillation, but the greater severity of recurrent strokes in Mexican-Americans was surprising," co-author Dr. Darin B. Zahuranec, an assistant professor of neurology at the University of Michigan Cardiovascular Research Center in Ann Arbor, said in an American Heart Association news release. One reason for the difference in stroke rates could be that Mexican-Americans may not have managed the blood-thinning drug warfarin often used to prevent stroke in the most optimal way, Zahuranec said. He and his colleagues did not evaluate outpatient use of warfarin, which might have contributed to the increased risk of stroke in Mexican-Americans.