Brain fatty acid levels linked to depression

A group of Israel researchers has discovered that rats with increased levels of the omega-6 fatty acid, arachidonic acid, show signs of depression.  There is also evidence that  a dietary deficiency in omega-3 fatty acids may be associated with depression.  The  ”phospholipid hypothesis” postulates decreased omega-3 fatty acid intake could be responsible for some types of depression.

The details of their findings appear in the Journal of Lipid Research  showing that omega-3 fatty acid concentration in the blood of depressed patients is lower than that in control patients.  Dr. Green in collaboration with Dr Gal Yadid of Bar-Ilan University, Ramat Gan used the Flinders Sensitive Line rats to investigate the link between omega-3 fatty acids and depression. They examined the brains of the depressed rats and compared them with brains from normal rats. Surprisingly, they found that the main difference between the two types of rats was in omega-6 fatty acid levels and not omega-3 fatty acid levels. Specifically, they discovered that brains from rats with depression had higher concentrations of arachidonic acid, a long-chain unsaturated metabolite of omega-6 fatty acid.

Arachidonic acid is found throughout the body and is essential for the proper functioning of almost every body organ, including the brain. It serves a wide variety of purposes, from being a purely structural element in phospholipids to being involved in signal transduction and being a substrate for a host of derivatives involved in second messenger function.

“The finding that in the depressive rats the omega-3 fatty acid levels were not decreased, but arachidonic acid was substantially increased as compared to controls is somewhat unexpected,” admits Dr. Green. “But the finding lends itself nicely to the theory that increased omega-3 fatty acid intake may shift the balance between the two fatty acid families in the brain, since it has been demonstrated in animal studies that increased omega-3 fatty acid intake may result in decreased brain arachidonic acid.”

Although far less attention has been paid to dietary requirements for omega-6 fatty acids, which can be found in most edible oils and meat, perhaps in the future depression may be controlled by increasing omega-3 fatty acid intake and decreasing omega-6 fatty acid intake.

———————————–
Article adapted by MD Only from original press release.
———————————–

Contact: Nicole Kresge
American Society for Biochemistry and Molecular Biology 
The American Society for Biochemistry and Molecular Biology (ASBMB) is a nonprofit scientific and educational organization with over 11,000 members in the United States and internationally. Most members teach and conduct research at colleges and universities. Others conduct research in various government laboratories, nonprofit research institutions, and industry.

The manuscript for the Journal of Lipid Research paper can be downloaded from clicking Here

Brisk Walk Helps You Stop Snacking

Researchers at the University of Exeter have found that a walk of just fifteen minutes can reduce chocolate cravings. The benefits of exercise in helping people manage dependencies on nicotine and other drugs have previously been recognised. Now, for the first time, newly-published research shows that the same may be true for food cravings.

Following three days of abstinence, 25 regular chocolate eaters were asked to either complete a 15-minute brisk walk or rest, in a random order. They then engaged in tasks that would normally induce chocolate cravings, including a mental challenge and opening a chocolate bar.

After exercise participants reported lower cravings than after rest. Cravings were not only reduced during the walk, but for at least ten minutes afterwards. The exercise also limited increases in cravings in response to the two tasks.

Professor Adrian Taylor comments: “Our ongoing work consistently shows that brief bouts of physical activity reduce cigarette cravings, but this is the first study to link exercise to reduced chocolate cravings. Neuroscientists have suggested common processes in the reward centres of the brain between drug and food addictions, and it may be that exercise effects brain chemicals that help to regulate mood and cravings. This could be good news for people who struggle to manage their cravings for sugary snacks and want to lose weight.”

Previous research has suggested that 97% of women and 68% of men experience food cravings. Craved foods tend to be calorie-dense, fatty or sugary foods, with chocolate being the most commonly reported. Chocolate has a number of biologically active constituents that temporarily enhance our mood with a result that eating it can become a habit, particularly when we are under stress and when it is readily available, and perhaps when we are least active.

Professor Taylor concludes: “While enjoying the occasional chocolate bar is fine, in time, regular eating may lead to stronger cravings during stress and when it is readily available. Recognising what causes us to eat high energy snacks, even if we have plans to not do so, can be helpful.”

“Short bouts of physical activity can help to regulate how energised and pleasant we feel, and with a sedentary lifestyle we may naturally turn to mood regulating behaviours such as eating chocolate. Accumulating 30 minutes of daily physical activity, with two 15 minute brisk walks, for example, not only provides general physical and mental health benefits but also may help to regulate our energy intake. This research furthers our understanding of the complex physical, psychological and emotional relationship we have with food.”

—————————-
Article adapted by MD Only from original press release.
—————————-

Contact: Sarah Hoyle
University of Exeter

Stress at Work Interfers with Sleep

Common hassles at work are more likely than long hours, night shifts or job insecurity to follow workers home and interfere with their sleep. That’s the conclusion of a University of Michigan study presented April 17 at the annual meeting of the Population Association of America. The study analyzes two nationally representative surveys of approximately 2,300 U.S. adults that monitored the same workers for up to a decade. Over that time, roughly half the respondents said they had trouble sleeping. “Together, work and sleep take up about two-thirds of every weekday,” said U-M sociologist Sarah Burgard. “But until now, very little research has focused on the connections between work and sleep for the average U.S. worker.”

Previous research has shown that lack of sleep can have serious consequences ranging from traffic accidents to health problems, chronic disease and mortality. As many as 70 million Americans suffer from some kind of chronic sleep disorder. But this is the first U.S. study to clarify the link between work and sleep quality for all workers, not just rotating shift workers or medical students, who have unusual work and sleep arrangements.

Because the surveys were prospective—following the same people over time—the researchers were able to show that work conditions affected sleep patterns, not the other way around. Their analysis controlled for initial sleep quality, health, pessimism and other confounding factors. Respondents who felt upset or bothered at work on a frequent basis, or had on-going personal conflicts with bosses or co-workers, were about 1.7 times more likely than others to develop sleep problems. “Massive changes over the past half-century have reshaped the workplace, with major implications for sleep,” Burgard said. “For many workers, psychological stress has replaced physical hazards. “Physical strain at work tends to create physical fatigue and leads to restorative sleep, but psychological strain has the opposite effect, making it more difficult for people to sleep.”

Burgard and graduate student Jennifer Ailshire also explored how work-family conflict, gender, education and job status affected the relationship between work and sleep. As women have entered the labor force in large numbers, dual-earner households and single-parent families have made the time-crunch a major factor, Burgard said. As expected, Burgard and Ailshire found that work-family conflicts and the presence of children under the age of three were significant predictors of negative changes in sleep quality.

Respondents with children under the age of three were about 2.2 times as likely to report poor sleep quality, but having young children did not explain the association between hassles at work and sleep quality. Surprisingly, however, they found no evidence that long hours, or working nights or weekends—strategies often adopted by working parents to juggle childcare and jobs while minimizing the use of baby-sitters or daycare facilities—had a negative impact on reported sleep quality.

In future research, Burgard plans to explore factors that could buffer workers from negative working conditions, such as age and a sense that one’s job is useful or helpful to others. She also plans to examine interventions that could break the link between work conditions and troubled sleep.

—————————-
Article adapted by MD Only from original press release.
—————————-

Sarah Burgard Ph.D., M.S. Burgard is assistant professor of sociology at the U-M College of Literature, Science, and the Arts; assistant professor of epidemiology at the U-M School of Public Health; and assistant research scientist at the U-M Institute for Social Research (ISR).

Source: Diane Swanbrow
University of Michigan