Weight gain = brain drain?

A new study published in Human Brain Mapping finds the more pounds you gain, the more your brain shrinks. The research found that elderly people who are obese have 8 percent less brain tissue than those of a normal weight. Individuals who are considered overweight, but not obese, have 4 percent less brain tissue.

The researchers examined brain scans of 94 people in their 70s – all were healthy and did not have any cognitive issues. They discovered that the overweight and obese individuals lost the majority of brain tissue in the frontal and temporal lobes of the brain; the areas responsible for planning and memory.

Dr. Paul Thompson, senior author of the study says:

“That’s a big loss of tissue and it depletes your cognitive reserves, putting you at much greater risk of Alzheimer’s and other diseases that attack the brain.”

Thompson also explained the brain images of the obese participants looked approximately 16 years older than the brains of those who are a normal weight, while the brains of overweight individuals looked about eight years older.

The World Health Organization estimates that approximately 300 million people worldwide are considered obese. WHO projects this number could increase to 700 million by 2015.

iStereotype

It turns out your iPod playlists say more about you than just the music you like. A new study conducted by the University of Cambridge finds that people form opinions about personality, values, ethnicity, and social class all based solely on musical taste.

80 young adults from the UK were asked to think about the fans of six different musical genres – rock, rap, pop, jazz, classical, and electronica. They rated fans on several personality dimensions, including extraversion and neuroticism. The participants also had to rate more personal characteristics, such as intelligence and attractiveness, as well as determine the probability that fans come from a certain ethnicity or social class.

Jazz enthusiasts are perceived as having the most positive personality. Participants labeled them as friendly and emotionally stable, while classical fans weren’t so lucky. They are considered friendly and intelligent, but also unattractive and boring.

Those with rock oriented taste are seen as artistic and rebellious; however, they are also viewed as emotionally unstable. Rap fans are labeled as athletic and energetic, but with a more hostile personality. A relationship was also established between genre and social class,  classical being associated with upper-class and rap with lower-classes.

The researchers found that the characteristics associated with each genre were relatively consistent, signifying that theses stereotypes are well established.

According to the study’s news release:

The researchers also argue that the way in which these genres are portrayed by artists and in the media appears to reinforce, and therefore perpetuate, such stereotypes.

‘It is now common practice to list your favourite bands on sites like MySpace or Facebook,’ Dr. [Jason] Rentfrow added. ‘This research shows that in doing so, many of us are also making clear public statements of who we are and how we should be perceived, whether we are conscious of that or not.’

The study is published in the journal Group Processes And Intergroup Relations. But we think the Specials said it all back in 1980.

There are no straight lines in nature

It turns out we really do walk in circles. A new study published in Current Biology finds that people have difficulty walking in a straight line when cues are not available to guide the way.

The researchers, from the Max Planck Institute for Biological Cybernetics, observed the walking patterns of the study participants using global positioning software. They had the volunteers walk unfamiliar terrain and found that they all had a tendency to walk in a circle or veer from a straight line.

According to the Associated Press, in one test, two of the participants were told to walk a straight line through the Sahara Desert during the day – both veered slightly from a straight path. Another participant walked through the desert at night and started out going straight; however, when it became cloudy he started to turn and ended up in the same direction in which he began.

A second test took place in the Bienwald forest in Germany with six participants. As soon as the sun disappeared, four ended up walking in circles even though they thought they were going straight. Two others walked when the sun was clearly visible and managed to walk in a reasonably straight line

One theory, according to Reuters, has said that people tend to walk in circles because of differences in leg strength, creating a tendency to move in one direction.

To test this, the researchers had the participants attempt walking a straight line while wearing a blindfold. They found that the same participant would walk in random directions and paths, without a bias toward a particular direction.

Lead researcher, Jan Souman, told Reuters:

“Walking in circles is therefore not caused by differences in leg length or strength, but more likely the result of increasing uncertainty about where straight ahead is.”

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New caffeine study induces headache

A new study conducted by the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway has found that caffeine seems to both cause and treat headaches; however, the scientists say there is no “obvious reason” for these results.

The study, published in the Journal of Headache and Pain, consisted of 50,483 people who participated in the Nord-Trøndelag Health Survey (HUNT) – a cross-sectional survey on a variety of health issues.

The analysis showed that people who consume high levels of caffeine are more likely to suffer from occasional headaches than those who consume lower amounts. However, low caffeine consumption is associated with a higher chance of chronic headaches (headaches for 14 days or more every month).

ScienceDaily explains the possible limitations of this study:

“The HUNT study is powerful because it is large-scale, population-based and cross-sectional, but when it comes to headaches, these characteristics make it difficult to establish cause-and-effect. For example, the frequency of non-migraine headache was found by researchers to be 18 per cent more likely in individuals with high caffeine consumption (500 mg per day or more) than among those with the lowest consumption (with mean levels at 125 mg per day).*

But does that mean that all that caffeine causes headaches – or that people who are more likely to suffer from headaches drink caffeinated beverages in search of relief? ‘Since the study is cross-sectional, it cannot be concluded that high caffeine consumption causes infrequent headache,’ the researchers write.”

Even so, the researchers advised those who experience occasional headaches to cut back on caffeine. They also suggested that those who suffer from chronic headaches might find relief by drinking caffeine.

Wait a minute. If you cut back, doesn’t that increase your chance for chronic headaches? This seems like a very vicious circle…

[*Editorial note, there is considerable variation in the range of caffeine in coffee drinks, ranging from 25mg to 214mg in one study of 97 espresso drinks in Australia. A single Starbucks espresso contains 75mg and a 12oz brewed coffee contains 260mg, according to Energy Fiend, while a Diet Coke contains 47mg, according to the Mayo Clinic.]

Parenting magazines endanger babies

A new study in Pediatrics warns that parenting magazines geared towards women who are pregnant routinely portray sleeping babies in inappropriate positions and environments. The researchers evaluated photographs of sleeping babies  in 28 magazines to see if they conformed to the American Academy of Pediatrics safe sleeping guidelines. The conclusion:

“More than one third of pictures of sleeping infants in magazines geared toward childbearing women demonstrated infants in an inappropriate sleep position, and two thirds of pictures of infant sleep environments were not consistent with AAP recommendations. Messages in the media that are inconsistent with health care messages create confusion and misinformation about infant sleep safety and may lead inadvertently to unsafe practices.”

As MedPage Today notes, the AAP “started recommending that babies sleep on their backs to reduce the risk of sudden infant death syndrome (SIDS) in 1992. It has since advised parents to remove pillows, soft bedding, and other objects from infant sleep areas.”

Times columnist has a numbers problem

New York Times columnist Bob Herbert isn’t happy with the way health care reform is going, complaining that the Obama administration has a  “secret and extremely troubling deal with the drug industry’s lobbying arm, the Pharmaceutical Research and Manufacturers of America”  that will result in the industry agreeing “to contribute $80 billion in savings over 10 years and to sponsor a multimillion-dollar ad campaign in support of health care reform.”

“The White House, for its part, agreed not to seek additional savings from the drug companies over those 10 years. This resulted in big grins and high fives at the drug lobby. The White House was rolled. The deal meant that the government’s ability to use its enormous purchasing power to negotiate lower drug prices was off the table… To get a sense of how sweet a deal this is for the drug industry, compare its offer of $8 billion in savings a year over 10 years with its annual profits of $300 billion a year.”

Not so fast, says Drugwonk Peter Pitts: that’s gross profit. The net profit of the top 20 pharma companies is $110 billion… (more)

Imagine that? Study finds men are dogs when it comes to sex; women, picky

Penetrating new research finds that men are much less picky when it comes to finding a one-night stand. Women, on the other hand, appear to have higher standards when choosing a man for casual sex.

Who are the people that spent their days researching the thoughts behind choosing a one-night stand? That would be Achim Schützwohl and his team located at Brunel University in England. They interviewed college students from the United States, Germany, and Italy – 427 males and 433 females in total.

Each student was asked to imagine being approached by a member of the opposite sex described as either “slightly unattractive,” “moderately attractive,” or “exceptionally attractive.” This imaginary person would then ask the student to go out on a date, go to their apartment, or go to bed with them. The participants would answer on a scale of 0 to 100 rating how likely they would be to accept each of these offers.

Men were more likely than the women participants to accept all of the requests regardless of attractiveness; however, they were – not surprisingly – more likely to accept when the woman was described as moderately or exceptionally attractive. According to Healthday’s article on the study, men had an average likelihood of 46 in response to the offer to sleep together, while women only had an average of 4.

The female participants placed more emphasis on looks. They were much more likely to accept the apartment and casual sex invitations from an exceptionally attractive man than from a moderately attractive or slightly unattractive man.

Perhaps more interesting was that the research found that cultural differences intruded on having an imaginary good time. German men were the least likely to accept the offers to go out, go to the apartment, or go to bed. Italian men were the most likely to accept the offer for a one-night stand, while American men accepted more offers than the German participants, but not as many as the Italians.

The study was published online in the journal Human Nature.

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Skin infections increase in U.S.

Hospital admissions for skin and soft tissue infections increased by 29 percent in the U.S. between 2000 and 2004, according to a study of hospital admission data which will appear in the September issue of Emerging Infectious Diseases

The researchers said the increase suggests, in light of cases of infectious pneumonia remaining steady, an  increasing prevalence of community-associated methicillin-resistant S. aureus (CA-MRSA). An advance copy of the study can be read here.

Hey kids, watch out for raccoon poop! (No, really)

If you thought childhood couldn’t become any more dangerous, a new study in the September issue of Emerging Infectious Diseases notes that the Raccoons answering the call of nature in urban gardens could spread “raccoon roundworm encephalitis.”  The bad news is that a), raccoons like to build latrines in people’s gardens, especially if they are near wooded areas, and b), nothing good for you ends with “encephalitis.”

Here’s the quick and dirty on raccoon roundworm: if you’re a human who manages to  ingest the worm’s eggs – and for good measure there can be up to 20,000 per gram of raccoon poop – the larvae don’t turn into worms inside your body.  Instead they make their way to the brain and eyes, and… well, you can read the news story at MedPage Today if you want to know precisely what follows.  Hint: It involves the word “encyst.”

51 percent of the yards studied by the researchers had raccoon latrines, and 23 percent of those contained worm eggs.

The good news is that there are only 14 known cases in 30 years of roundworm encephalitis, which is also known by the considerably more difficult to pronounce name of baylisascariasis. But many of these occurred where raccoon latrines were in proximity to children’s play areas. The study is a valuable reminder  that the call of nature often provides some of the deadliest, if easily desposed of, risks.

An advance publication version of the study is available via the Centers for Disease Control here.

Associated Press reduces U.S. heroin addiction?

The war on drugs got a nice fillip from the Associated Press in its story on heroin addiction in Afghanistan. According to the AP:

“There are at least 200,000 opium and heroin addicts in Afghanistan – 50,000 more than in the much bigger, wealthier U.S., according to the U.S. Department of Health and Human Services and a 2005 survey by the U.N. A new survey is expected to show even higher rates of addiction, a window into the human toll of Afghanistan’s back-to-back wars and desperate poverty.”

This seems to suggest that there are only 150,000 heroin addicts in the U.S., a surprisingly small number for a country of 300 million.  In part, this all depends on how you define addiction or dependence or heroin use. For example, the latest data from the 2007 National Survey on Drug Use and Health counts 213,000 Americans over the age of 12 abusing or being dependent on heroin in the past year.

But the National Institute on Drug Abuse cautions that this may be an underestimation of the scope of heroin abuse, something that the  National Survey highlights when it reports that  335,000 people sought treatment for heroin addiction in 2007. And here’s the thing, the number of people seeking treatment for addiction tends to be much lower than the actual number of those who are addicted. In sum, we may not know exactly how many heroin addicts there are in the U.S., but we can be certain it is significantly more than that reported by the AP.