Booster Shots

Oddities, musings and news from the health world

Category: research

Pregnant moms living near cellphone towers: No worries, study says

June 22, 2010 |  4:02 pm

Expectant parents may have one less thing to worry about. British researchers say a new study shows that the children of women who live near cellphone towers during pregnancy do not have an increased risk of childhood cancer.

Cell tower no risk for childhood cancer The researchers, from Imperial College London’s School of Public Health, identified all 1,926 cases of childhood cancers in Britain from 1999 to 2001. In 529 cases, either the mother’s whereabouts during pregnancy or the radio-frequency exposure from nearby cellphone towers could not be determined. Each of the remaining 1,397 cases was matched with four healthy children of the same age and gender. All of the kids had similar demographic characteristics.

The team also gathered detailed data about all 81,781 cellphone towers that were operational in the country during that time, including each tower’s location, height, output power and how many antennas it had.

Then they crunched the numbers. In virtually every permutation of their calculations, there was no correlation between the cellphone towers and the cancer cases.

For instance, the mothers whose children were diagnosed with cancer lived an average of 1,173 yards from a cellphone tower while they were pregnant -- statistically indistinguishable from the 1,211 yards that separated the other pregnant women from their nearest cellphone towers. Tallying up the total power output of all cellphone towers within 766 yards of each pregnant woman’s home, they found that both groups had nearly the same exposure -- 2.89 kilowatts for the mothers of cancer victims and 3.00 kilowatts for the other mothers.

Only one of their models revealed a difference that was statistically significant, though just barely. In that case, higher radio-frequency exposure was associated with a reduced risk of cancer of the brain or central nervous system. (This result calls to mind a mouse study from last year that found that electromagnetic radiation from cellphones actually protected mice from Alzheimer’s.) The results were published online Tuesday by the British Medical Journal.

The British researchers admitted their study would have been stronger if there had been some way to determine the actual radiation exposure for each pregnant woman instead of relying on mathematical models. They also would have liked to have tracked the exposure of babies after they were born, but the necessary data weren’t available. Still, they said that if the cellphone towers had doubled the risk for these childhood cancers, the odds that their study would have picked up on it were greater than 90%.

In an editorial, John Bithell of the University of Oxford’s Childhood Cancer Research Group wrote that the study was convincing.

“Clinicians should reassure patients not to worry about proximity to mobile phone masts,” they wrote. “Moving away from a mast, with all its stresses and costs, cannot be justified on health grounds in light of current evidence.”

-- Karen Kaplan

Photo: Cellphone towers. Credit: Sean Masterson / EPA

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To heck with negative publicity! Doctors still dig those drug-company freebies

June 22, 2010 | 12:10 pm

Doctor The public may have begun to raise a collective eyebrow at the largesse offered to doctors from drug makers and medical device manufacturers. Even the companies themselves have started to acknowledge the potential conflict of interest, or the perception of it. Medical schools too have begun to take a harder line on the matter. But individual doctors? They still kind of like this whole gift-giving, or rather, gift-getting practice.

Researchers at Mount Sinai School of Medicine surveyed doctors and medical students there to assess their opinions of industry interactions, gifts and the appropriateness of such things. True, the results are a reflection only of doctors and medical students at that institution, but the data offer a snapshot of how perspectives can vary, by specialty, by training level, by type of gift.

Overall, surgeons were fairly enthusiastic about relationships with drug and device manufacturers; pediatricians ... not so much. Here's the full doctors-and-gifts study.

The researchers write in their conclusion:

"Our overall finding of favorable physician attitudes toward industry suggests that individual physicians may be out of synch with trends among medical schools and public opinion and even industry itself. Although the evidence that physician-industry marketing relationships result in patient harm is inconclusive, US medical schools have increasingly adopted restrictive policies toward industry interactions, and there is widespread public concern that financial relationships between physicians and industry lead to conflicts of interest."

Here are two stories that provide a fuller examination of the broad issue: Doctor, Just a Little Something for You and And Now, There's a Growing Push for Reform.

Plus, a look at what medical schools are doing, A Pox on Drug Maker Freebies, Say Some Doctors, and the beginning of drug company pullback, Eli Lilly to Disclose Payments to Doctors.

Of note, this new survey found that most respondents believed other doctors were more likely to be swayed by such gifts than they themselves were.

-- Tami Dennis

Photo illustration credit: Myung J. Chun


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Rodent of the Week: Why women are more vulnerable to psychiatric stress

June 18, 2010 |  5:13 pm

It’s well known that women are more susceptible to some kinds of psychiatric disorders than men. For instance, studies have found that depression and post-traumatic stress disorder are twice as common among women as among men. But why?

Rodent One theory involves a brain hormone called corticotropin-releasing factor, or CRF. It is responsible for kicking off the stress response, and it is regulated by the female sex hormone estrogen. So perhaps estrogen causes female and male brains to respond differently to CRF.

To test this, scientists at Children’s Hospital of Philadelphia and the nearby Thomas Jefferson University subjected male and female rats to a swim stress test. Then they studied their brains in minute detail.

It turned out that the female rats were more responsive to CRF – it registered more strongly in their brains than it did in the male rats. What’s more, the female rats weren’t able to tone down the hormone after their stressful swims. But the male rats were – their brain cells changed in a way that prevented some of the CRF from doing its usual job.

“The findings identify molecular and cellular mechanisms that could result in enhanced sensitivity of female rats to CRF and a decreased ability to adapt to excessive CRF,” the researchers wrote. But they cautioned that further research is needed to see if the same gender differences are at play in human brains.

The study was published this week in the June issue of Molecular Psychiatry.

-- Karen Kaplan

Photo: Advanced Cell Technology Inc.

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Harvard researchers conduct a real-world test of soda taxes

June 17, 2010 |  4:00 pm

Another day, another study on soda taxes.

Soda But this one isn’t based on mathematical models or unreliable food frequency questionnaires. This time, researchers at Harvard implemented a temporary soda tax in the cafeteria of the school's Brigham and Women’s Hospital in Boston. Then they waited to see whether actual people changed their drinking habits.

It turns out that they did. During a four-week period when the price of a 20-ounce bottle of soda went up by 45 cents – which amounted to a 35% price increase – sales fell by 26%. Meanwhile, sales of bottled diet soda rose by 20%. (The researchers said they were unable to change the prices of fountain drinks, so those soft drinks were not subject to the tax.)

Prices for full-calorie soda went back to normal after the test period, but sales ticked back up only slightly. Then researchers posted fliers around the cafeteria that said:

"Lose up to 15-25 pounds in one year and decrease your risk of diabetes by 1/2. Just skip one regular soda per day. For zero calories, try diet soda or water."

Those fliers remained up for four weeks, but sales of bottled soda didn’t fall during that period – in fact, they rose slightly.

Finally, the researchers reinstated the 45-cent soda tax while keeping the fliers up for another four weeks. That cut into sales of bottled soda, prompting a 36% decline compared with the weeks before the prices first changed.

The researchers concluded that taxes can work – only the price increase had a statistically significant effect on sales of sugared soda. When the tax was in place, diners switched to diet soda and coffee; sales of water and fountain drinks stayed the same throughout the study.

The researchers also wondered whether people who skipped their usual sodas would reward themselves by buying more snacks and desserts, but sales of those treats didn’t change either.

Of course, there was no way to tell whether anyone actually lost weight – or reduced their risk of health problems like obesity and diabetes – as a result of the tax.

The results were published online Thursday by the American Journal of Public Health.

-- Karen Kaplan

Photo: Higher prices encouraged consumers to switch from regular soda to diet soda or coffee. Credit: Justin Sullivan / Getty Images

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Hey, driver! Put down the cellphone -- for your relationship's sake

June 16, 2010 |  3:39 pm

Cellphone Talking on a cellphone while behind the wheel is obviously dangerous to your driving, But it also might be dangerous to your relationship.

In a recent issue of Family Science Review, University of Minnesota professor Paul Rosenblatt discusses the risks, as he sees them, of communicating while driving. He contends that the same factors that make driving while talking on a cellphone risky — distracted concentration and slower reactions times — can also take their toll on the conversation at hand.

It makes sense. Effective communication via cellphones is hard enough given the absence of visual cues and facial expressions. Factor in the distractions created by traffic lights, other motorists and the possibility of an errant child or animal dashing into the road and the chances increase dramatically that a driver will respond thoughtlessly, miss an important comment or, perhaps worse, deliver a delayed response where there really, really shouldn’t be a delay.

A family social science professor in the university’s College of Education and Human Development, Rosenblatt explained that the motive for his article came from his field of study, as well a general desire to help people.

“It just seemed obvious to me…. That kind of communication is not simple. There are more mistakes likely to happen. People misunderstand each other, focus less, and respond slower, which could all be negative for relationships,” Rosenblatt said in an interview.

To date, Rosenblatt has yet to actually test his theory -- citing both the financial and logistical difficulties involved in doing so. But, despite this lack of scientific evidence, Rosenblatt has given his theory a lot of thought, relying on experiences in his own life and conversations with his students as proof that his theory has merit.

For the less imaginative among us, Rosenblatt surmised five possible scenarios in which cellphone usage while driving could lead to relationship problems:

- A phone call to the driver requesting that they run an errand;
- A phone call delivering good news;
- A phone call delivering bad news;
- Arguments over the phone;
- Apologies made over the phone.

Surely, you can think of (or recall) other examples.

Overall, considering what we’re now learning about the perils of talking while driving …

- Most people can't talk on a cellphone and drive safely, study finds

- A new Rx from the doctor: hang up and drive

… maybe we could all benefit from swallowing Rosenblatt’s bitter pill. It might be time to just shut up, hang up, and drive.

-- Jessie Schiewe

Photo credit: Los Angeles Times


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Free range eggs contain a little something extra: pollutants

June 16, 2010 |  1:16 pm

Here’s some disconcerting news for health-conscious eaters who favor eggs from free-range hens: A Taiwanese study found that the eggs contain much higher levels of industrial pollutants than eggs laid by caged hens.

Freerange The researchers focused on two types of pollutants, polychlorinated dibenzo-p-dioxins and dibenzofurans (known collectively as PCCD/Fs), which are released into the environment by municipal waste incinerators, factories and other industrial sources. A report from the International Program on Chemical Safety says the chemicals have caused cancer, liver damage, problems with the skin and nervous system, reproductive problems and other undesirable effects in animals.

The researchers collected 60 free range eggs from farms in southern Taiwan and compared them with 120 eggs from caged hens that were purchased throughout the country. Then they measured the levels of 17 kinds of PCCD/Fs.

For the free range eggs, the levels ranged from 6.18 to 41.3 picograms per gram of lipid, with an average value of 17.5 pg/g. Levels for the caged eggs ranged from 2.85 to 19.8 pg/g, with an average value of 7.65.

The researchers also calculated the toxic equivalency quotient (TEQ) for both kinds of eggs using a system endorsed by the World Health Organization. The levels for the free range eggs were 5.7 times higher than the levels for the caged eggs.

In addition, 17% of the free range eggs had levels that European regulators have deemed unsafe for consumption. All of the caged eggs were easily in the safe zone, the researchers found. The results were published in the latest edition of the Journal of Agricultural and Food Chemistry.

The researchers believe the free range eggs have more contaminants because they are found in the environments where free range hens roam. Studies have found the chemicals in “feedstuffs, soil, plants, worms and insects,” they wrote. Their own measurements of dirt from free range farms persuaded them that soil contamination is at least partly to blame.

The problem probably isn’t limited to Taiwan. Scientists have also found the same trend in the European Union, and one study found that about 10% of free range eggs exceeded the safety limit set by regulators there.

“The issue of contamination in free range eggs could be a global issue, and more research should be done to identify the factors from the external environment that influence and modify the PCDD/F levels in eggs from free range hens,” the authors wrote.

In case you were wondering, their research was not sponsored by the commercial egg-laying industry. The scientists had grants from the National Science Council of Taiwan and the Taiwanese Ministry of Education.

— Karen Kaplan

Photo: These free-range chickens seem to be enjoying their time outdoors, but with dioxins lurking in the environment, it may not be good for them – or us – after all. Credit: Steve Osman / Los Angeles Times

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Obesity takes a toll on sexual health

June 15, 2010 |  6:29 pm

It is well known that obesity raises one’s risk of developing type 2 diabetes, heart disease, stroke, high blood pressure and certain types of cancer, among other health problems. But how does it affect one’s sex life? Leave it to the French to provide the answer.

Sex In a study to be published online Wednesday in the British Medical Journal, researchers from the National Institute of Health and Medical Research in Paris and the London School of Hygiene and Tropical Medicine report that obese men and women have more health issues related to sex than people of normal weight. Using data collected during lengthy phone interviews with more than 10,000 French adults, they found that:

  • Compared with women of normal weight, obese women were 30% less likely to have had a sexual partner in the previous year.
  • Obese women in their late teens and 20s were three times as likely to have met a sexual partner online and twice as likely to have watched a pornographic movie.
  • Among women in their late teens and 20s, obese women were four times more likely than normal-weight women to report an unintended pregnancy or an abortion.
  • Perhaps this was because they were 70% less likely to use birth control pills and eight times more likely to rely on “less effective methods, such as withdrawal.”

As for the guys:

  • Compared with men of normal weight, obese men were 70% less likely to have had more than one sexual partner in the previous year (but equally likely to have had at least one).
  • Obese men were more than twice as likely than normal-weight men to have experienced erectile dysfunction in the previous year.
  • Among men in their late teens and 20s, the odds of contracting a sexually transmitted disease in the previous five years were more than 10 times greater for obese men than for men of normal weight.

“The study lends a new slant to a familiar message: that obesity can harm not only health and longevity, but your sex life,” concludes an editorial that accompanies the study.

-- Karen Kaplan

Photo: Carrying around extra pounds can put a damper on your sex life, researchers say. Credit: iStockphoto

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And now, medical images for your weekend browsing pleasure

June 13, 2010 |  7:13 am

Exam.room Remember those oddities we promised -- as in "Booster Shots: Oddities, musings and news from the health world"? The venerable New England Journal of Medicine is here to help.

The journal doesn't call them "oddities," of course. The journal calls them "featured images in clinical medicine," and it offers one up every week.

This week's offering is cutis marmorata in decompression sickness. It's interesting enough, but perhaps not what nonspecialists would consider odd. To most people, mottled-looking skin is mottled-looking skin.

But the Diphylloborthrium latum found during a colonoscopy? Fascinating. Absolutely fascinating. And the video...

-- Tami Dennis

Photo: If these walls could talk...

Credit: Los Angeles Times

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Rodent of the Week: How habits are formed

June 11, 2010 |  1:00 pm

Rodent_of_the_week When I was in high school, I had to drive a long distance on a freeway to get to school. After arriving, I often wondered how I got there. I didn't remember the drive or even thinking about driving.

This feeling is a common (and, yes, somewhat scary) experience that a group of neuroscientists think they can better explain. In an experiment with rats, researchers at MIT identified two distinct neural circuits in the brain that show distinct changes when the rats were learning to navigate a maze and, later, after they mastered the task.

The rats were placed in a maze that had chocolate sprinkles at the end. The activity in specific parts of their brains was analyzed as they learned the maze, which included a T-juncture where they had to stop and choose to turn right or left. The rats performed the maze repeatedly until they had learned it.

The study showed that one specific neural circuit became stronger with practice. A second neural circuit showed high activity occurring at times when the rats had to make a decision in the maze. But as they learned the maze, activity in this circuit declined. The task had become habitual.

So, arriving at school in one piece wasn't just a matter of luck. "It is good to know that we can train our brains to develop good habits and avoid bad ones," the lead author of the study, Ann Graybiel, said in a news release.

Understanding how specific regions of the brain change through learning could help in developing new treatments for brain-based diseases. The study was published Thursday in the journal Neuron.

-- Shari Roan

Photo credit: Advanced Cell Technology Inc.


Heart attacks fall in one diverse community, with perhaps lessons for others

June 10, 2010 |  3:08 pm

Statins Take detailed data (if you can get it) on heart attacks in a large, diverse patient population, do a bit of number-crunching based on patient age and gender, and see what you get. Kaiser Permanente researchers could, and did, in Northern California -- and what they got was an impressive reduction in heart attacks since 2000.

Overall, heart attacks declined 24% in patients age 30 and older. The rate of a severe type of heart attack, known as ST-segment elevation myocardial infarction, fell by 62%.

The results were published Wednesday in the New England Journal of Medicine. Here's the abstract of that heart-attack study and some details from the research division's news release.

The researchers write in their study conclusion:

"Increasing emphasis has been put on measures to reduce risk factors at the individual and community levels, including public bans on smoking and lower target levels of low-density lipoprotein (LDL) cholesterol and blood pressure; these changes have resulted in improved control of risk factors over time."

They also point out that such improvements were achieved despite the community's overall tendency to gain weight and develop diabetes.

Here's more about heart attack types, from the Cleveland Clinic. And an explainer of the two main types -- ST segment elevation myocardial infarction, or STEMI, and non-ST segment elevation myocardial infarction, or NSTEMI -- from About.com.

In the former, a blood clot blocks an artery completely (as opposed to partially), affecting more heart muscle and causing more damage.

-- Tami Dennis

Photo: The use of statins and other cardioprotective drugs, now taken by many people, certainly haven't hurt heart attack numbers, the researchers say.

Credit: Bob Chamberlin / Los Angeles Times

 



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