Working Too Hard? Physically Demanding Jobs Tied to Higher Risk of Heart Disease

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April 23rd, 2013

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While physical activity can lower the risk of heart disease, two studies suggest that jobs involving hard manual labor may harm, rather than help the heart.

Presenting at the annual EuroPRevent 2013 meeting, two separate groups report on the potential dangers of physically demanding work and provide deeper understanding of how manual labor may differ from a gym workout or a run with respect to the heart.

The first, from researchers at Harokopio University in Athens, involved 250 first-time stroke patients, 250 patients who experienced their first heart event, and 500 healthy controls, all of whom ranked their jobs on a scale of how physically demanding they were. Those reporting more labor-intensive occupations showed higher rates of heart events; for each one unit drop in the ranking of physical intensity, the participants showed a 20% decline in their chances of having a heart event. The association held even after the researchers adjusted for possible heart disease risk factors such as sex, BMI, smoking, diabetes and diet.

A second study conducted by researchers from the Department of Public Health at the University of Ghent in Belgium found similar evidence that physically demanding labor could increase risk of heart problems, particularly among those who also exercised during their leisure time. The trial, involving a cohort of over 14,000 middle-aged men without heart disease, provided more details about how occupational and leisure activity might interact. The participants answered questions about their jobs, heart health and any physical activity they did for leisure between 1994 and 1998.

After following the men for slightly more than three years on average, the researchers found that those with jobs involving lower levels of physical labor who also engaged in moderate to intense leisure-time activity enjoyed a 60% reduced risk of heart events. But men whose jobs were more physically demanding and who also exercised when they were off the clock showed a nearly 70% increased risk of heart problems. After adjusting for other factors that could contribute to heart disease risk, the men with the physically demanding jobs were more than four times likely as those with less physically-oriented occupations to develop heart disease if they also exercised regularly.

“The hypothesis based on our study and other recent literature is that physical activities done on the job usually include more static activity types which do not have a training effect on the cardiovascular system, but have an overloading effect on the system,” says study author Dr. Els Clays. Jobs that require activities like heavy lifting, awkward postures and high physical exertion are known to increase blood pressure and heart rate. “If people are exposed to that for a long time, like multiple hours during the day, that can really have an adverse effect on their cardiovascular health,” says Clays.

Jobs that demand a lot of heavy lifting appear to be more taxing on a body in a way that doesn’t benefit health like going for a run, according to Clays. The researchers of the first study also suggest that the stress accompanying physically demanding jobs may counteract the positive effects of exercise. It’s also possible that those with physically draining jobs may have less access to health care; such occupations generally involve manual labor and often pay less and provide limited health insurance. With less access to preventive health therapies, rates of chronic conditions such as heart disease may be higher.

The findings reinforce the complex relationship between physical activity and heart disease, and suggests that doctors should take into account the types of physical activity people do in different settings. “There is increasing evidence in recent years showing occupational demands do not have the beneficial effect general physical activity has. This study really confirms that,” says Clays. “The basic message is we really need more detailed measures for physical activity.”

Why Circumcision Lowers Risk of HIV

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April 18th, 2013

Promising trials hinted that circumcision could lower rates of HIV infection, but until now, researchers didn’t fully understand why.

Now, in a study published in the journal mBio, scientists say that changes in the population of bacteria living on and around the penis may be partly responsible.

Relying on the latest technology that make sequencing the genes of organisms faster and more accessible, Lance Price of the Translational Genomics Research institute (TGen) and his colleagues conducted a detailed genetic analysis of the microbial inhabitants of the penis among a group of Ugandan men who provided samples before circumcision and again a year later.

While the men showed similar communities of microbes before the operation, 12 months later, the circumcised men harbored dramatically fewer bacteria that survive in low oxygen conditions. They also had 81% less bacteria overall compared to the uncircumcised men, and that could have a dramatic effect on the men’s ability to fight off infections like HIV, says Price. Previous studies showed that circumcised men lowered their risk of transmitting HIV by as much as 50%, making the operation an important tool in preventing infection with the virus. Why? A high burden of bacteria could disrupt the ability of specialized immune cells known as Langerhans cells to activate immune defenses. Normally, Langerhans are responsible for grabbing invading microbes like bacteria or viruses and presenting them to immune cells for training, to prime the body to recognize and react against the pathogens. But when the bacterial load increases, as it does in the uncircumcised penile environment, inflammatory reactions increase and these cells actually start to infect healthy cells with the offending microbe rather than merely present them.

That may be why uncircumcised men are more likely to transmit HIV than men without the foreskin, says Price, since the Langerhans cells could be feeding HIV directly to healthy cells. His group is also investigating how changes in the levels of cytokines, which are the signaling molecules that immune cells use to communicate with each other, might be influenced by bacterial populations.

“There is a real revolution going on in our understanding of the microbiome,” says Price, who is also professor of occupational and environmental health at George Washington University. “The microbiome is almost like another organ system, and we are just scratching the surface of understanding the interplay between the microbiome and the immune system.”

Previous work suggested that changes in the bacterial populations in the gut, for example, could affect obesity, and other studies found potential connections between microbial communities and the risk for cancer, asthma and other chronic conditions.

by Alice Park

Surprising Differences Between the Male and Female Brain

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April 16th, 2013

By Lisa Collier Cool

It’s not as simple as Mars vs. Venus, but scientists have identified intriguing differences in how men and women think that influence emotions, memory, business success, and even longevity.

In the largest brain imaging study ever conducted to compare male and female brains, Daniel Amen, MD, and other researchers analyzed imaging scans of 26,000 people. They discovered that women showed increased blood flow in 112 of the 128 brain regions they studied, indicating that on average, women’s brains are much more active than men’s.

The most striking difference between the sexes was that women have a much higher level of activity in the prefrontal cortex, an area that’s sometimes called “the brain’s CEO” because it governs planning, organization, impulse control, and learning from mistakes.

In the soon-to-be published study, men’s brains showed greater activity in regions associated with visual perception, tracking objects through space, and form recognition. However, these gender differences don’t mean that one sex has a mental edge over the other—just that their brains are wired differently.

“Even when men and women succeed at the same task, they tend to call on different strengths and areas of the brain to achieve this result,” says Dr. Amen, author of Unleash the Power of the Female Brain: Supercharging Yours for Better Health, Energy, Mood, Focus, and Sex (Harmony, 2013).

Here’s a closer look at some gender differences Dr. Amen and other researchers have identified—and how we can use them to our advantage.

Men Have Bigger Brains, But It Doesn’t Make Them Smarter

On average, men’s brains are 8 to 10 percent bigger than women’s brains. While that may not seem surprising, given that men’s bodies tend to be larger overall, even after correcting for body weight, it’s been estimated that men have about 4 percent more neurons than women do.

But before men jump on these findings as proof of brain superiority, scientists point out that these size differences aren’t distributed uniformly in all brain regions. In a study using MRI scans, Dr. Jill Goldstein at Harvard Medical School found that compared to men, women have larger volume in both the frontal cortex (the inner CEO) and the limbic cortex, involved in emotional responses.

“This may explain why women tend to be less impulsive and more concerned with emotions than men are,” says Dr. Amen, who theorizes that a bigger and more active frontal cortex suggests that women are wired for leadership—and may actually be better bosses than men.

Consider the intriguing result of a recent study in which teams of men and women were assigned tasks that involved brainstorming, decision-making, and solving visual puzzles. Teams were given collective IQ scores based on their performance.

Conventional wisdom would infer the team made up of people with the highest individual IQ scores (thus the highest total IQ) should emerge victorious. However, the collective IQ scores were based on how they completed the assigned tasks as a team. And the teams with the highest collective IQs were those with more women, Harvard Business Review reports.

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Women Have Better Memories, Worse Sense of Direction

Dr. Amen’s research shows that women have greater activity in the brain’s hippocampus. “Guys, if you wonder why your wife or girlfriend never forgets anything, here’s your answer: The hippocampus is the part of the brain that helps store memories.”

In a 2008 study, Swedish psychologists found significant sex differences in several types of memory, favoring women in all almost all of the areas studied.

Specifically, women excelled at recalling words, pictures, objects, and everyday events. They also outperformed men on such tasks as recalling the location of car keys or remembering faces (particularly those of other women).

However, the psychologists also found that men have the edge in a type of memory called visuospatial processing. For example, the study results suggested that a man would be more likely to remember how to find his way out of the woods.

There’s quite a bit of scientific evidence that men have a keener sense of direction than women do, adds Dr. Amen. “Overall, men are better at getting from point A to point B, but are also less likely to realize it if they take the wrong turn. That’s why men are famously reluctant to ask for directions: They don’t realize they’re lost.”

Women Live Longer, But On Average Men Are Happier

Studies suggest that women have greater self-control and levels of what Dr. Amen terms “appropriate worry.” For example, women tend to take better care of their health, visit the doctor more often, and behave less recklessly.

Women also have lower rates of substance abuse, anti-social personality disorder, and ADHD. And they’re 14 times less likely to go to jail—and even get fewer traffic tickets than men do.

“These points are actually quite fascinating,” says Dr. Amen, “because appropriate worry about negative consequences could be a key factor in why women outlive men. In one large study, researchers found that those with a “don’t worry, be happy” attitude—i.e. young men with motorcycles—died earlier from fatal accidents and preventable illness.”

However, the dark side of women’s higher level of worry is that they are more prone to anxiety disorders and depression, which strikes women at nearly double the rate it does men, according to the Mayo Clinic. At some point in life, about 1 in 5 women develops clinical depression.

One reason why women may be more vulnerable is that men’s brains, on average, produce 52 percent more serotonin, according to a recent study by University of Montreal researchers. This feel-good brain chemical has been dubbed “the happy hormone.”

Dealing With Stress at a New Job

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April 16th, 2013

By Rheyanne Weaver

Getting a new job can cause the most wonderful feeling in the world, especially in the current economy, but sometimes new changes can also add additional stress.

If you feel a little stressed at your new job, experts have some suggestions to help you make a smooth transition.

Ramani Durvasula, a clinical psychologist and author of “You Are Why You Eat,” said in an email that it is normal to be stressed when you start a new job, because there are many reasons to be stressed.

“Expectations are high, the economy is tough, it is a time of proving oneself, of learning a new routine, meeting new people, learning new personalities, mastering a new schedule,” she said. “All of this while managing the responsibilities of day to day life.”

Stress is not the only mental health side effect of starting a new job.

“Some people may report pronounced anxiety, fatigue, difficulty sleeping, problems concentrating, and in people with preexisting conditions such as depression, may even report a worsening of those symptoms,” Durvasula said.

Stress and anxiety in small amounts aren’t necessarily detrimental, though.

“If you aren’t feeling them, I would wonder if you aren’t taking it seriously,” she said. “Stress and anxiety are ways of your system saying slow down, something is coming around the bend. You can use these signals to be mindful, to be organized in your new job.”

There are other ways to succeed at your new job while also enduring some stress along the way.

“Make sure you communicate so you are clear on the expectations laid out for you, and so you don’t make mistakes in your assumptions,” Durvasula said. “Take the time to learn about your new coworkers and team around you. Get to know the place you work in.”

Here are a few ways she suggests relieving some of your new job stress:

  • Make sure you get enough sleep
  • Eat well and exercise
  • “Organize life as much as possible (especially the night before) so mornings aren’t chaotic.”
  • “Turn to others for help when possible during the transitional phase. Let your support network know you are going through a transition so they can be there for you.”
  • “Make some pleasurable time for you.”
  • “Use those weekends well to give yourself mini-breaks and take care of you so you have the energy to manage the transition.”

Here are some ways Durvasula suggests to make your mental health a priority during this time of transition:

  • Give yourself a break.
  • Don’t be your own worst critic.
  • Be mindful and think about how you react and respond to situations.
  • “Even if time is tight, you can still take five minutes to breathe or meditate.”
  • “If you are in therapy, this is a good time to continue it so you have a place to discuss fears and feelings.”
  • “Self care is critical.”

Lisa Bahar, a licensed marriage and family therapist, said in an email that stress at a new job can be useful because it motivates employees and makes them work more effectively. A new job can also relieve anxiety once you master new skills and pay your bills, along with meeting new people.

“The positive is that the individual finds meaning perhaps and purpose, feels valued, is engaged in life and not excluded, is needed and feels as though there is worth to their life, that they can offer a skill that others value which engages them in a way that may have gone stagnant due to lack of employment,” Bahar said.

But sometimes it can have the opposite effect.

“Anxiety related to expectations and learning a new task can be challenging to deal with, as well as depression of feeling inadequate,” Bahar said. “On the other hand, the opportunity can relieve these symptoms if the individual has a strong social, spiritual and family support.”

She said there can also be some struggles with social anxiety, because for some people it takes more time to get adjusted and comfortable working with new people.

Bahar added that the best way to cope with stress is to be your own cheerleader. Engage in self-care and give yourself positive affirmations that you are doing well. She said to also make sure to take your lunch and breaks, and leave work on time.

“Continue and don’t impulsively leave the job, make sure you start what you finish, give yourself plenty of affirmations, acknowledge your accomplishments, smile gently and remind yourself you are valued no matter what,” she added.

Bahar also stressed that even if your job isn’t what you were expecting it to be, give yourself some time to adjust properly before you start looking elsewhere.

What does your birthday have to do with immune disorders?

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April 16th, 2013

By Alexandra Sifferlin, TIME.com

The month in which babies are born can affect how their immune systems develop, and even how vulnerable they are to autoimmune diseases.

Scientists studying the neurological disorder multiple sclerosis, in which the body’s own immune cells destroy the protective coating around nerves and can lead to paralysis and loss of other functions, have long been puzzled by the “birth month effect.” Many patients with MS are born in the spring, and rates of the disease are lowest for those born in November.

Some have speculated that insufficient levels of vitamin D, which the skin produces when exposed to sunlight, on the mom’s part could play a role, since babies born in May are gestated during the colder, darker months, while winter babies are in utero during the spring and summer.

Now a study published in JAMA Neurology shows that this hunch may be correct, and suggests a mechanism for how the vitamin might be driving immune system development.

Researchers in the UK studied 50 babies born in London in May and 50 babies born in November between 2009 and 2010. They sampled blood from the newborns’ umbilical chords and recorded levels of vitamin D and a specific type of immune cell known as autoreactive T-cells.

T-cells are the white blood cells that battle pathogens like bacteria and viruses, but autoreactive T-cells are aberrant versions that mistake the body’s own cells as foreign and attack them as they would an unwanted infection.

The researchers found that babies born in May had vitamin D levels that were 20% lower than those in babies born in November, and almost double the amount of autoreactive T-cells. They speculate that vitamin D may be important in some way in educating T cells about how to recognize self cells; this occurs in the thymus, and errors in the training could lead to higher levels of the destructive T cells.

The connection between vitamin D and immune disorders first emerged from population studies that showed people who lived further away from the equator, in places with less sunlight, were at higher risk of developing MS. But the researchers caution that their results still don’t suggest that lower levels of the vitamin cause autoimmune disorders like MS.

So it’s not clear yet whether supplements of vitamin D could help to lower rates of the disease — especially for those conceived in July and born in May. In fact, experts continue to debate how much vitamin D is appropriate for otherwise healthy people when it comes to preventing disease, since studies on the subject are conflicting. The Institute of Medicine currently recommends that adults get about 600 IU daily.

More research is needed to figure out whether pregnant women might need to take more vitamin D in order to strengthen their babies’ immune systems, but doctors now have a better understanding of what birth months have to do with how the immune system develops.

This article was originally published on TIME.com