Tuesday, February 14, 2012

Air pollution might harm brain, study says

It’s well established that dirty, sooty air is no good for your lungs and probably not great for your skin. But new research indicates it can damage your brain, too.
A study in the journal of the Archives of Internal Medicine shows that air pollution accelerates cognitive decline in women.
And with a new federal report showing Southern Californians are at the highest risk of death due to air pollution, this study adds to the growing body of grim evidence showing air pollution and healthy bodies don’t mix.
“We keep learning about more adverse effects (from pollution) than we thought possible,” said Jean Ospital, health effects officer with the South Coast Air Quality Management District, who was not involved with the current research.
“I’m not sure I find these results surprising,” he said, “but I’m also not sure I would have expected them if you’d asked me 10 years ago.”
The new research, conducted by a team of researchers from Chicago, Boston, Baltimore and Philadelphia, looked at the effect of coarse particulate matter in the air on the cognitive health of older women.
“We, as a society, are on the verge of dealing with an unprecedented number of people having dementia,” said Jennifer Weuve, lead author of the study and a researcher at Chicago’s Rush University Medical Center. “We know relatively little about how to prevent dementia, but we do know cognitive decline is related to dementia.”
Weuve pointed to research showing a link between air pollution and cardiovascular disease.
“It turns out that cardiovascular disease may play a role in cognitive decline," said Weuve, who is a researcher at Rush’s Institute for Healthy Aging. "So if we understand how to prevent or delay these cognitive increments, maybe we can prevent or delay dementia.”
And not just at an individual level, she said.
“What’s interesting about air pollution," Weuve said, is that “other factors that may cause dementia are generally found at the more individual level – diet, weight, smoking. And we can help to try to prevent them at that level. But in this case, we’re looking at something that we can do to intervene at a broad scale, with society at large."
"It's a whole new way to think about prevention for dementia and cognitive decline," she said.
Weuve and her team turned to one of the largest epidemiological datasets and cohorts in medical research, the Nurses' Health Study, to begin looking for links between pollution and cognitive health.
The Nurses' Health Study, which researchers began in 1976, is a dataset based on information collected over time from 121,700 female registered nurses between the ages of 30 and 55 living in 11 different states.
Between 1995 and 2001, Weuve and her colleagues invited participants of the Nurses' Health Study to participate in a study of cognition. The team was able to get data from nearly 20,000 women.
To establish pollutant exposure, the team collected air pollution exposure data from the Environmental Protection Agency, which they correlated with the location of each woman's home and place of employment. Then they called each woman six times on the phone, over six years, and tested their cognitive abilities.
They found that higher levels of long-term exposure to air pollution particles was associated with significantly faster cognitive decline.
She said more research needs to be done. For instance, is the cognitive decline they observed due to cardiovascular issues, or are pollutants having a direct effect on the brain?
She said more research also will be needed to confirm her work.
"The bottom line," said Sam Atwood, a spokesman for the South Coast Air Quality Management District, "is that in Southern California, we have some of the highest levels of particulate matter in the country, and we are working as quickly as possible at reducing those levels."

Falak undergoes procedure to reduce brain infection level

New Delhi, Feb 14 (PTI) Doctors at AIIMS today conducted another surgery on battered two-year-old Falak to bring down the infection level in the brain even as she continued to be in a critical but stable state. According to doctors at the AIIMS Trauma Centre who are attending on baby Falak, the surgery was conducted as an "alternative attempt" to fight brain infection. "We did a bedside procedure wherein we put a tube in the brain that drains outside instead of the spine. This has been undertaken as an attempt to bring down the infection level in her brain. Because of this infection, she continues to remain critical but stable," neurosurgeon Deepak Agarwal, who has been treating her, said. With today's procedure, Falak has undergone a total of four surgeries since her admission in the hospital on January 18. Falak was brought to the hospital on January 18 with severe head injury, both her arms broken, bite marks all over her body and her cheeks branded with hot iron. Dr Agarwal said, "With the damage she has suffered in the brain, if she survives, there are high chances that she will be mentally retarded or have a low conscious level. At present, we are trying to do our level best to get her out of the ICU." Doctors also said that she still continues to remain on ventilatory support as she cannot breathe on her own. She underwent a life saving surgery of the brain immediately after her admission here. Later on, it was followed by two more surgeries.

How our brain recognizes expressions

Researchers have identified two areas in the brain that are critical for either detecting or distinguishing emotions from facial expressions. People with damage to these areas cannot understand the wide variety of facial expressions that convey social signals, which are important foranyone trying to navigate their way in society.
FaceDr. Lesley Fellows, lead investigator, and her student Ami Tsuchida studied a large sample of patients with damage to various regions within the prefrontal cortex (PFC), testing to see where damage had the biggest impact on emotion recognition.
The result of their tests led to conclusions about two sub-regions of the PFC that until now had been little studied.
“Patients with damage to the ventromedial PFC had a hard time distinguishing a neutral facial expression from emotional ones,” said Dr. Fellows.
“Patients with left ventrolateral PFC damage recognized that an emotion was present in the expression, but had difficulty telling one emotion from another.
“The ability to cross-over research and clinical work enables crucial advances in science and medicine, a prime example of the benefits of The Neuro’s integrated model as a combined hospital and research institute,” Dr. Fellows added.
The research adds to our understanding of how our brains detect emotional expressions and interpret the meaning of those expressions.
The findings could help to understand some of the difficulties in social behaviour seen in neuropsychiatric illnesses including certain forms of dementia, autism, or after a traumatic brain injury.
The study has been published in the journal Cerebral Cortex. 

Child abuse leaves a long-lasting mark on brain: Study

Child abuse leaves a long-lasting mark on brain: Study
Washington: Abuse and maltreatment during childhood can shrink important parts of the brain that could lead to psychiatric disorders like depression, drug addiction and other mental health problems later in life, according to Harvard scientists.

The link between childhood abuse and reduced brain volume in parts of the hippocampus could help find new, better ways to treat survivors of childhood abuse, the scientists said.

"These results may provide one explanation for why childhood abuse has been identified with an increased risk for drug abuse or psychosis," study researcher Martin Teicher of
Harvard University told LiveScience.

"Now that one can look at these sub-regions in the brain, we can get a better idea of what treatments are helping."

For their study, published in the journal Proceedings of the National Academies of Sciences, Teicher and his team used magnetic resonance imaging (MRI) to scan the brains of 193 individuals between 18 and 25 years old, who had already undergone several rounds of testing to be qualified.

They then analysed the size of areas in the hippocampus and compared the results with the patient`s history.

It was found that those who had been abused, neglected or maltreated -- based on well-established questionnaires – as children had reduced volume in certain areas of hippocampus by about six per cent, compared with kids who hadn`t experienced child abuse.

They also had size reductions in a related brain area, called the subiculum, which relays the signals from the hippocampus to other areas of the brain, including the dopamine system, also known as the brain`s "reward center".

Volume reduction in the subiculum has been associated with drug abuse and schizophrenia, as well.

In animal experiments, including non-human primates, this hippocampus can shrink because of high exposure to the stress hormone cortisol during two developmental periods: between ages 3 and 5 and between ages 11 and 13, the researchers said.

These stress hormone levels stop the growth of neurons in the hippocampus, leading to smaller volume in the adult human brain. Changes in hippocampus volume have been linked to depression, schizophrenia and other psychiatric disorders.

High stress levels from childhood abuse and maltreatment during important brain development periods may be causing the decreased hippocampus volume that the researchers saw.

"This region has a lot of receptors for the stress hormone cortisol. It interacts with receptors in these neurons to effect the development and the branching of these neurons,"
Teicher said. "The neurons are responding by either shrinking or not going into neurogenesis [and making new neurons]."

These brain changes can cause mental illness, explaining why childhood abuse is highly correlated to diseases like depression and drug addiction, Teicher said.

"By damaging it to some degree you may cause the dopamine system to be disregulated, and disregulation of the dopamine system has been linked to drug abuse and psychological illnesses," he added.

Brain Scans Could Reveal If Your Relationship Will Last

When you're in the early stages of falling in love, you might hide it from friends and family. But you can't hide it from neuroscientists. By charting brain activity with an fMRI (functional magnetic resonance imaging) machine, scientists can spot telltale regions of your brain glowing joyously when you look at a photograph of your beloved.
But new research suggests that neuroscientists can tell you much more than what you already know (that you're madly in love). Like fortune-tellers who read brains instead of palms, they have begun to figure out how to determine the fate of your relationship by studying your brain activity alone. And armed with the knowledge of the brain responses they're looking for, you too may be able to find clues in your own behavior as to whether you and your loved one will be happily married years from now, or bitterly separated and wondering why it all fell apart.
Not all in-love brains look alike. Several years ago, Xiaomeng Xu, now a postdoctoral fellow at Brown University School of Medicine, and her colleagues performed fMRI scans on 18 Chinese men and women who reported being in the early stages of romantic love. Though all the study participants showed clear signs of love — looking at the face of their beloved triggered a flurry of activity in the areas of their brains involved in reward and motivation — the researchers identified subtle differences between the individuals' brain scans. When the team followed up with the study participants 18 months later to learn how their budding relationships had turned out, they found a surprisingly strong correlation between certain characteristics in the original brain scans and the participants' relationship status a year and a half later. [13 Scientifically Proven Signs You're in Love]
The team detailed its results in the journal Human Brain Mapping in early 2010. Now, another two years have passed, and the researchers have contacted 12 of the original study participants. Half of the participants are still in the relationships they had just begun at the time of the brain scans three and a half years ago; the other six aren't. Among the admittedly small sample, there is a striking divide between the original brain activity of the people whose relationships lasted and those whose relationships fell apart.

Rose-tinted shades
"Even with this small number of people, the results are really interesting," said Lucy Brown, a leading expert on the neuroscience of love at Albert Einstein College of Medicine and a member of the research team.
Two key aspects of the participants' brain activity correlated with their relationship longevity, Brown said. Among the people whose relationships became long-term, looking at a picture of their beloved "caused a decrease in activity in regions that we associate with making judgments, and also a decrease in activity in systems associated with a person's sense of self," she said. "Sense of self" can be thought of awareness of one’s own existence, interests and desires.
These two brain responses, and the associated behavioral traits, suggest that a promising relationship is one in which people refrain from judging their new partners, and instead, tend to overrate them, even finding the positive aspect of a patently negative trait. A promising new romance is also one in which people give great importance to their loved one’s interests and desires, even to the subjugation of their own. Both these tendencies seem to be "a huge help in the longevity of a relationship," Brown told Life's Little Mysteries, a sister site to LiveScience.
The researchers plan to conduct a larger-scale study to see if the correlation between relationship longevity and the two fMRI signatures — corresponding to the two behavioral traits — is as strong as their small data set implies. They also intend to investigate whether certain people more easily exhibit the traits in question, and are thus inherently more suited to long-term attachments, than others.  "We would like to know, 'Does relationship longevity depend on the other person, the relationship or who you are?'" Brown said. "A lot of it may be who you are." [Why Do We Have Sex?]
Similarly, new work indicates that what might be fortuitous in a new relationship doesn't necessarily bode well later on.
Realism sets in
According to brand-new work by Bianca Acevedo, a postdoctoral researcher at Cornell University, the characteristics identified by Xu, Brown and their colleagues point only to a happy future when exhibited by brand-new couples. When it's time to get married, your brain needs to change its ways.
Acevedo did fMRI scans of newlyweds who had been with their partners for an average of four years. She looked for correlations between their brain responses and how happily married they said they were one year later. Many of the study participants reported feeling less in love with their new husbands or wives after a year of marriage, but some actually reported feeling more in love. She focused on the latter set. "The question was, is there any activation around the time of the wedding that's associated with an increase in love over the first year of the marriage," Acevedo said.
Unlike people in the early stages of a relationship, in the case of newlyweds, "it's a good sign to have heightened activity in the areas of the brain associated with the representation of ourselves and others," Acevedo said. "In particular, it was a good sign to see activity in areas that are part of the mirror neuron system. The way this works is, if you stretch your arm out, we see neurons firing in these areas, but if you see someone else stretching their arm out, the same neurons fire off. So this idea of including the other in the self — when looking at a picture of your partner causes activities in these areas — this predicts an increase in love over time."
Furthermore, unlike the study of brand-new relationships, in which a tendency to overrate your partner indicates that your relationship with them will last, Acevedo's study of newlyweds found that activation of the brain regions involved in judgment and decision-making correlated with an increase in love over the course of their first year of marriage. "It's true that when people show nonjudgment in the beginning of their relationships, that helps them get hooked on that person. That's OK in the beginning, but later, it's important to see things clearly when you're stepping into a lifelong commitment," she said.
Taken altogether, the new research suggests the following: Selflessness and idealizing your partner will carry you through the first few years of romance. Later, when things get serious, your sense of self must re-blossom, but it must now be intimately tied together with your sense of your partner. And at that point, assessing him or her accurately — accepting the good with the bad — bodes well for a happy marriage.

Mediterranean Diet May Be Good for the Brain

A Mediterranean diet may reduce small-vessel damage to the brain, according to a new study published in the Archives of Neurology. In other words, a diet made up of fruits, vegetables, olive oil, legumes, whole grains, little red meat and a glass of red wine here and there may be good for your brain.
Researchers from University of Miami and Columbia University analyzed food frequency questionnaires filled out by 966 participants in the Northern Manhattan Study, a study designed to identify risk factors for stroke and coronary disease. Study participants then underwent brain MRI scans to analyze the white matter hyperintensity volume, which is a sign of small vessel disease. Researchers found that people who closely followed a Mediterranean diet had fewer brain lesions than those who had higher-fat and more red meat-based diets. People who exercised more were also more likely to consume foods associated with the Mediterranean diet.
“Normally, these lesions are associated with hypertension, high-cholesterol, diabetes and age,” said Dr. Clinton Wright, associate professor of neurology at Miller School of Medicine at the University of Miami Medical Center and senior author of the study. “We saw that there was a relationship between diet and this marker of small vessel disease. Those who adhered to a more Mediterranean diet had less small vessel damage.”
Small vessel disease is a condition in which the small arteries in the heart become narrowed. The disease can cause signs of heart disease, including chest pain and artery blockages, and it is most common in women and diabetics, according to Mayo Clinic. The lesions are also linked to cognitive disorders, including Alzheimer’s disease.
“Of course, this was an association study, and we’d need randomized trials to prove this association,” said Wright.
The Mediterranean diet has already been associated with reducing the risk of heart disease and dementia.
As Wright explained, the brain is made up of grey matter and white matter. Grey matter is made up billions of cell bodies and neurons, while white is the connection between those neurons.
“They’re like wires that connect computers,” said Wright. “When small vessels get damaged due to hypertension or diabetes or smoking and the like, those little vessels get damaged in a way that they become thicker and blood doesn’t flow to the brains as well, or there is fluid from the vessel leaking out, and that’s what causes those white matter lesions.”
Dr. Ken Fujioka, director of nutrition and metabolic research at Scripps Health Clinic in San Diego, said the biggest single difference in the Mediterranean diet versus many other diets is the high amount of monounsaturated fats (found in vegetable oils, fish, nuts oils and avocadoes) that have been shown to have multiple health benefits.
Fujioka said he agreed with the findings, but said, “as we move forward we will get to a point for some people [where] this will be the best diet, but for others, a different diet might be better and the future is trying to find out which diet [is best] for which patient.”
Authors note that, because the study was observational, it’s difficult to decipher whether the results were due to overall healthy dietary patterns or to the foods themselves, but Wright said he hopes the observational research will be a jumping off point for clinical trials and experiments. While Dr. David Katz, director of the Yale Prevention Center, said this confirms past research that has positive health benefits in the Mediterranean diet, and it puts emphasis on brain health.
“The topic that the health of the brain and the health of the body are largely one and the same deserves more attention than it gets,” said Katz.