New research on rats seems to find a connection between yo-yo dieting and compulsive eating.
According to researchers at the Boston University School of Medicine (BUSM), a chronic cyclic pattern of overeating followed by undereating reduces the brain’s ability to feel reward and may drive compulsive eating.
The finding suggests that future research into the treatment of compulsive eating behavior should focus on rebalancing the mesolimbic dopamine system, the part of the brain responsible for feeling reward or pleasure, researchers say.
“We are just now beginning to understand the addictive-like properties of food and how repeated overconsumption of high sugar — similar to taking drugs — may affect our brains and cause compulsive behaviors,” said corresponding author Pietro Cottone, Ph.D., an associate professor of pharmacology and experimental therapeutics at BUSM and co-director of the Laboratory of Addictive Disorders.
To better understand compulsive and uncontrollable eating, Cottone and his research team performed a series of experiments on two groups of rats. One, the cycled group, received a high-sugar, chocolate-flavored diet for two days each week and a standard control diet the remaining days of the week, while the control group received the control diet all of the time.
The group that cycled between the palatable food and the less palatable food spontaneously developed compulsive, binge eating on the sweet food and refused to eat regular food, the researchers discovered.
Both groups were then injected with a psychostimulant amphetamine, a drug that releases dopamine and produces reward, and their behavior in a battery of behavioral tests was then observed.
While the control group predictably became very hyperactive after receiving amphetamine, the cycled group did not.
Furthermore, in a test of the conditioning properties of amphetamine, the control group was attracted to environments where they previously received amphetamine, whereas the cycled group were not.
Finally, when measuring the effects of amphetamine while directly stimulating the brain reward circuit, the control group was responsive to amphetamine, while the cycled group was not, according to the findings.
After investigating the biochemical and molecular properties of the mesolimbic dopamine system of both groups, the researchers determined that the cycled group had less dopamine overall, released less dopamine in response to amphetamine, and had dysfunctional dopamine transporters — proteins that carry dopamine back into brain cells — due to deficits in the mesolimbic dopamine system.
“We found that the cycled group display similar behavioral and neurobiological changes observed in drug addiction: specifically, a crash in the brain reward system,” Cottone said. “This study adds to our understanding of the neurobiology of compulsive eating behavior.
“Compulsive eating may derive from the reduced ability to feel reward. These findings also provide support to the theory that compulsive eating has similarities to drug addiction.”
“Our data suggest that a chronic cyclic pattern of overeating will reduce the brain’s ability to feel reward — feeling satiated. This results in a vicious circle, where diminished reward sensitivity may in turn be driving further compulsive eating,” said lead author Catherine (Cassie) Moore, Ph.D., a former graduate student in the Laboratory of Addictive Disorders at BUSM.
The study was published in the journal Neuropsychopharmacology.
Source: Boston University School of Medicine
When older adults become socially isolated, their health and well-being can suffer. Now a new study suggests a link between being socially isolated and osteoarthritis (arthritis), a condition that causes joint pain and can limit a person’s ability to get around.
The findings are published in the Journal of the American Geriatrics Society.
Arthritis patients often have other health issues which may increase their risk of becoming socially isolated. These include anxiety and depression, being afraid to move around (because arthritis makes moving painful), physical inactivity and being unable to take care of themselves.
About 30 percent of adults over 65 have arthritis to some degree, especially in their leg joints. Despite that, until now there has been little research on the link between arthritis and social isolation.
Researchers analyzed data from the European Project on OSteoArthritis (EPOSA) study. They wanted to examine any potential links between arthritis and social isolation, and to identify the disease’s contribution to social isolation.
EPOSA is a study of 2,942 adults between the ages of 65 to 85 years old who live in six European countries: Germany, Italy, the Netherlands, Spain, Sweden, and the UK. In all, 1,967 people, around the age of 73, participated in the study. Half of the participants were women, and almost 30 percent had arthritis.
The researchers looked at whether the participants were socially isolated at the beginning of the study as well as 12 to 18 months later. The participants completed questionnaires that kept track of how often they connected socially with friends and family members and how often they volunteered or participated in social activities.
At the start of the study, almost 20 percent were socially isolated. Those who weren’t socially isolated tended to be younger, had higher incomes and more education. They were also more likely to be physically active, had less physical pain, had faster walking times and were in better all-around health.
Of the 1,585 participants who weren’t considered socially isolated at the beginning of the study, 13 percent had become socially isolated 12 to 18 months later. They reported that their health and osteoarthritis had worsened, they were in more pain, had become less physically active, had slower walking times, and had depression and problems with thinking and making decisions.
The researchers say the findings suggest that osteoarthritis can increase the risk of social isolation. In particular, having problems with thinking and making decisions, as well as having slower walking times, is associated with an increased risk of becoming socially isolated.
Since social isolation can lead to poorer health, the researchers suggest that older adults with arthritis may benefit from engaging in physical activity and social activities. Specifically, they suggest that health care providers might refer people to senior centers where activities are specially designed for people with arthritis.
Source: American Geriatrics Society
New research suggests hope is a trait that can predict resilience and recovery from anxiety disorders.
In a new study, clinical psychologist Dr. Matthew Gallager and colleagues examined the role of hope in predicting recovery in a clinical trial of adults in cognitive behavior therapy (CBT) for common anxiety disorders.
Historically, the concept of hope has long stirred opinion. In the 16th century, German theologian Martin Luther celebrated its power, claiming “Everything that is done in this world is done by hope.” Two centuries later, Benjamin Franklin warned that “He that lives upon hope will die fasting.”
In the study, Gallagher — University of Houston associate professor of clinical psychology — assessed the role of hope in predicting recovery among a clinical trial of 223 adults. In the trial, adults were receiving cognitive-behavior therapy (CBT) for one of four common anxiety disorders: social anxiety disorder, panic disorder, generalized anxiety disorder and obsessive-compulsive disorder.
Gallagher discovered that psychotherapy can result in clear increases in hope and that changes in hope are associated with changes in anxiety symptoms. His findings appear in the journal Behavior Therapy.
“In reviewing recovery during CBT among the diverse clinical presentations, hope was a common element and a strong predictor of recovery,” said Gallagher. He also reports that moderate-to-large increases in hope and changes in hope were consistent across the five separate CBT treatment protocols.
In terms of psychotherapy, hope represents the capacity of patients to identify strategies or pathways to achieve goals and the motivation to effectively pursue those pathways.
Significantly, the results of this study indicate that hope gradually increases during the course of CBT, and increases in hope were greater for those in active treatment than for those in the waitlist comparison.
The magnitude of these changes in hope were consistent across different CBT protocols and across the four anxiety disorders examined, which underscores the broad relevance of instilling hope as an important factor in promoting recovery during psychotherapy.
“Our results can lead to a better understanding of how people are recovering and it’s something therapists can monitor. If a therapist is working with a client who isn’t making progress, or is stuck in some way, hope might be an important mechanism to guide the patient forward toward recovery,” said Gallagher.
Hope is closely related to other positive psychology constructs, such as self-efficacy and optimism, that have also been shown to have clear relevance to promoting resilience to and recovery from emotional disorders, said Gallagher.
Gallagher’s research is part of a larger project examining the efficacy of CBT for anxiety disorders led by Dr. David H. Barlow, founder and director emeritus of the Boston University Center for Anxiety and Related Disorders.
Source: University of Houston
Video: New research links excess neural activity — the flickering light seen in this image — to reduced longevity. Credit: Yankner lab, Harvard Medical School.
The brain’s neural activity — long implicated in disorders ranging from dementia to epilepsy — also plays a role in how long we live.
The study, led by scientists in the Blavatnik Institute at Harvard Medical School and based on findings from human brains, mice, and worms, suggests that excessive activity in the brain is linked to shorter life spans, while suppressing overactivity can extend life.
Neural activity refers to the constant flicker of electrical currents and transmissions in the brain. Excessive activity, or excitation, could manifest in numerous ways, from a muscle twitch to a change in mood or thought, according to the researchers.
“An intriguing aspect of our findings is that something as transient as the activity state of neural circuits could have such far-ranging consequences for physiology and life span,” said study senior author Dr. Bruce Yankner, a professor of genetics and co-director of the Paul F. Glenn Center for the Biology of Aging.
Neural excitation appears to act along a chain of molecular events famously known to influence longevity — the insulin and insulin-like growth factor (IGF) signaling pathway, the researchers explain.
The key in this signaling cascade appears to be a protein called REST, previously shown by researchers in the Yankner Lab to protect aging brains from dementia and other stresses.
Study results could lead to the design of new therapies for conditions that involve neural overactivity, such as Alzheimer’s disease and bipolar disorder, the researchers said.
The findings also raise the possibility that certain medicines, such as drugs that target REST, or certain behaviors, such as meditation, could extend life span by modulating neural activity, they said.
Human variation in neural activity might have both genetic and environmental causes, which would open future avenues for therapeutic intervention, Yankner added.
The researchers began their investigation by analyzing gene expression patterns — the extent to which various genes are turned on and off — in donated brain tissue from hundreds of people who died at ages ranging from 60 to over 100.
The information was collected through three separate research studies of older adults. Those analyzed in the current study were cognitively intact, meaning they had no dementia, the researchers noted.
The researchers immediately noticed a striking difference between the older and younger study participants, Yankner said. The longest-lived people — those over 85 — had lower expression of genes related to neural excitation than those who died between the ages of 60 and 80.
Next came the question that all scientists confront: Correlation or causation? Was this disparity in neural excitation merely occurring alongside more important factors determining life span or were excitation levels directly affecting longevity? If so, how?
To answer these questions, the researchers conducted a barrage of experiments, including genetic, cell, and molecular biology tests in the model organism Caenorhabditis elegans, analyses of genetically altered mice, and additional brain tissue analyses of people who lived for more than a century.
These experiments revealed that altering neural excitation does indeed affect life span and illuminated what might be happening on a molecular level, the researchers said, noting all signs pointed to the protein REST.
REST, which is known to regulate genes, also suppresses neural excitation, the researchers found.
Blocking REST or its equivalent in the animals led to higher neural activity and earlier deaths, while boosting REST did the opposite.
The researchers also discovered that people who lived to 100 and beyond had significantly more REST in the nuclei of their brain cells than people who died in their 70s or 80s.
“It was extremely exciting to see how all these different lines of evidence converged,” said study co-author Dr. Monica Colaiácovo, a professor of genetics at Harvard Medical School, whose lab collaborated on the C. elegans work.
The researchers found that from worms to mammals, REST suppresses the expression of genes that are centrally involved in neural excitation, such as ion channels, neurotransmitter receptors, and structural components of synapses.
Lower excitation activates a family of proteins known as forkhead transcription factors. These proteins have been shown to mediate a “longevity pathway” via insulin/IGF signaling in many animals. It’s the same pathway that scientists believe can be activated by caloric restriction, according to the researchers.
In addition to its emerging role in staving off neurodegeneration, discovery of REST’s role in longevity provides additional motivation to develop drugs that target the protein, the researchers said.
Although it will take time and many tests to determine whether such treatments reduce neural excitation, promote healthy aging, or extend life span, the concept has captivated some researchers.
“The possibility that being able to activate REST would reduce excitatory neural activity and slow aging in humans is extremely exciting,” said Colaiácovo.
The study was published in Nature.
Source: Harvard Medical School
Students who take part in physical exercises like running in place during school lessons do better in tests than students who stick to sedentary learning.
A meta-analysis of 42 studies around the world conducted by researchers at the University College London, Leiden University, the National University of Singapore, and the University of Sydney, aimed to assess the benefits of incorporating physical activity in academic lessons. This approach has been adopted by schools that want to increase activity levels among students without reducing academic teaching time.
Typical activities include using movement to signify whether a fact is true or false, or jumping on the spot a certain number of times to answer a math question, the researchers explained.
The study concluded that incorporating physical activity had a large, significant effect on educational outcomes during the lesson, assessed through tests or by observing pupils’ attention to a given task. It also had a smaller effect on overall educational outcomes, as well as increasing the students’ overall levels of physical activity.
“Physical activity is good for children’s health, and the biggest contributor of sedentary time in children’s lives is the seven or eight hours a day they spend in classrooms,” said lead author Dr. Emma Norris of University College London. “Our study shows that physically active lessons are a useful addition to the curriculum. They can create a memorable learning experience, helping children to learn more effectively.”
“These improvements in physical activity levels and educational outcomes are the result of quite basic physical exercises,” added co-author Dr. Tommy van Steen of Leiden University in The Netherlands. “Teachers can easily incorporate these physical active lessons in the existing curriculum to improve the learning experience of students.”
For the study, researchers looked at data from 12,663 students between the ages of three and 14. Nearly half of the studies took place in the United States, with seven conducted in Australia, five in the UK, four in the Netherlands, and one in China, Croatia, Ireland, Israel, Portugal, and Sweden.
In one of the 42 studies analyzed, eight- and nine-year-olds simulated traveling the world by running in place in between answering questions relating to different countries.
The research team, also led by Norris at UCL, concluded that the children were more active and more focused on the task than peers in a control group, following teachers’ instructions more closely.
In another study in the Netherlands, primary school children who took part in physically active lessons three times a week over two years made significantly better progress in spelling and mathematics than their peers, equating to four months of extra learning gains, according to researchers.
The study published in the British Journal of Sports Medicine.
Source: University College London
Going for that pint of ice cream after a bad breakup may not do as much damage as you think. A new study shows that despite the emotional turmoil, people on average do not report gaining weight after a breakup.
The study, which included researchers from Penn State, investigated the German concept of “kummerspeck” — excess weight gain due to emotional eating — which literally translates to “grief bacon.”
According to the researchers, although hoarding food after a breakup may have made sense for humans thousands of years ago, modern humans may have grown out of the habit.
“Food was much scarcer in the ancestral environment, so if your partner abandoned you, it could have made gathering food much harder,” said Dr. Marissa Harrison, associate professor of psychology at Penn State Harrisburg.
“It may have made sense if our ancestors hoarded food after a breakup. But our research showed that while it’s possible people may drown their sorrows in ice cream for a day or two, modern humans do not tend to gain weight after a breakup.”
The findings are published in the Journal of the Evolutionary Studies Consortium.
The researchers say it is well documented that people sometimes use food as a way to cope with negative feelings and that emotional eating can lead to unhealthy food choices. Because breakups can be stressful and emotional, it could potentially trigger emotional eating.
In addition, ancient relationship dynamics may have made packing on the pounds after a breakup evolutionarily advantageous.
“Modern women of course have jobs and access to resources now, but back then, it was likely that women were smaller and needed more protection and help with resources,” Harrison said.
“If their partner left or abandoned them, they would be in trouble. And the same could have gone for men. With food not as plentiful in the ancestral world, it may have made sense for people to gorge to pack on the pounds.”
Harrison also noted that the existence of the word “kummerspeck” itself suggested that the phenomenon existed.
The research team conducted two studies to test the theory that people may be more likely to gain weight after a relationship breakup. In the first experiment, they recruited 581 people to complete an online survey about whether they had recently gone through a breakup and whether they gained or lost weight within a year of that breakup.
Most of the participants — 62.7 percent — reported no weight change. The researchers were surprised by this result and decided to perform an additional study.
For the second experiment, the researchers recruited 261 new participants to take a different, more extensive survey than the one used in the first study. The new survey asked whether participants had ever experienced the dissolution of a long-term relationship, and whether they gained or lost weight as a result.
The survey also asked about participants’ attitudes toward their ex-partner, how committed the relationship was, who initiated the breakup, whether the participants tended to eat emotionally, and how much participants enjoy food in general.
While all participants reported experiencing a break up at some point in their lives, the majority of participants — 65.13 percent — reported no change in weight after relationship dissolution.
“We were surprised that in both studies, which included large community samples, we found no evidence of kummerspeck,” Harrison said. “The only thing we found was in the second study, women who already had a proclivity for emotional eating did gain weight after a relationship breakup. But it wasn’t common.”
Harrison added that the results may have clinical implications.
“It could be helpful information for clinicians or counselors with patients who tend to eat emotionally,” Harrison said. “If your client is going through a breakup and already engages in emotional eating, this may be a time where they need some extra support.”
Victoria Warner, a Penn State Harrisburg graduate student, was the lead author of this study. Samantha Horn from Penn State Harrisburg and Susan Hughes from Albright College also participated in this work.
Source: Penn State