Parents of college students: Next time you check in on your kid, here's a question to add to your repertoire. After you've asked how her money's holding out, is she getting enough sleep, and how's that psych paper coming along, you might want to inquire "So, honey, have you by any chance taken up smoking with a hookah?"

A hookah?

Apparently lots of college students are using hookahs, or waterpipes, to smoke tobacco. A study in the current issue of the Journal of Adolescent Health showed that of 744 Virginia Commonwealth University students surveyed, 43 percent had used a hookah to smoke tobacco during the past year, and 20 percent had done so during the past month.

Hookah use entails heating tobacco (often sweetened and flavored) with charcoal; the smoke passes through a water chamber that cools it down before the smoker inhales. Apparently it's a social activity: There are hookah cafes near college campuses, and students share hookahs at parties.

The study suggests that misconceptions about the health risks associated with hookah use are rampant among users and non-users alike. Of those who reported using a hookah within the past month, 44 percent thought hookahs were safer than cigarettes, and 58 percent said there was no likelihood of becoming addicted to tobacco if you're using a hookah. Even the kids who didn't use hookahs were way off on this: Almost 60 percent called hookahs safer than cigarettes, and nearly 42 percent said the likelihood of addiction was nil.

Um, wrong and wrong. Both hookah and cigarette smoke contain tar and carbon monoxide, both of which can cause lung cancer and other diseases, and nicotine, the stuff you get addicted to. Hookah use might even be more dangerous, according to the study, because users tend to smoke them longer and take more puffs from them than they would from a cigarette, leading to their inhaling as much as 100 times more smoke.

Here's what a Mayo Clinic pulmonologist has to say on the risks of hookah smoking.

The study's researchers, from Virginia Commonwealth University, suggest that teens and young adults need to be hit over the head (my wording, not theirs) with the message that hookah smoking is bad for their health. Until some public agency can get moving on that, maybe we parents should get the ball rolling.

Think you'll sound silly inquiring about hookahs? Fine. Just send your kid a link to this blog.

Does your doctor have good manners? And how much does that matter to you?

We depend on physicians to analyze our symptoms, make diagnoses and spell out treatment plans. It's nice when they can do all that with a well-developed bedside manner. At the very least, we expect them to be civil.

But Michael Kahn, a psychiatrist at Beth Israel Deaconess Medical Center in Boston and assistant professor of psychiatry at Harvard Medical School, detects a deficit in doctors' manners. In the current issue of the New England Journal of Medicine, Kahn reports, "When I hear patients complain about doctors, their criticism often has nothing to do with not feeling understood or empathized with. Instead, they object that 'he just stared at his computer screen,' 'she never smiles,' or 'I had no idea who I was talking to.'"

Kahn goes on to say that when he himself was recently hospitalized, he was treated by a European-born surgeon whose presence and demeanor he found "impeccable."

"I wasn't left thinking, 'What compassion,'" Kahn notes. "Instead, I found myself thinking, 'What a professional,' and even (unexpectedly), 'What a gentleman.'"

Kahn suggests that patients "may care less about whether their doctors are reflective and empathic than whether they are respectful and attentive."

Medical schools already try to teach doctors to be compassionate and humane. But, Kahn argues, that may be easier said than done; some people are more naturally compassionate than others, and it might not be possible to teach compassion to those who aren't inclined that way.

That's where Kahn's notion of "etiquette-based medicine" comes in. He proposes a manners checklist, a simple document that spells out the basic things a physician should say and do when meeting with a patient. Kahn's model 6-point checklist includes such items as "Ask permission to enter the room; wait for an answer," "Shake hands (wear glove if needed), " and "Sit down. Smile if appropriate."

Kahn's checklist is inspired by the work of Johns Hopkins University School of Medicine professor Peter Pronovost, who designed a checklist that has drastically reduced the number of infections in critical-care hospital patients. (Like Provonost's, Kahn's list is aimed at doctors treating patients in hospital, but he says it could be used in clinics and private offices, too.)

"It's not like doctors are bad people," Kahn told me on the phone. "It's just that these courtesies get overlooked."

So, let's hear some stories. How polite are the doctors you deal with? How much does it matter to you? And do you think it affects your care and recovery?

Like many of her peers in the early 1960s (okay, it was 1960), my mom didn't even consider breastfeeding; for her (meaning, for me), it was bottles all the way. And I guess I turned out okay, brainpower-wise.

But just think how smart I could have been if she'd nursed me!

A new study, the largest ever of its kind, shows that exclusive breastfeeding for three or more months is tied to higher IQ scores and teacher-evaluated performance in reading, writing, math, and other subjects down the road. (The babies in the study underwent the IQ and other testing when they were 6 1/2 years old.) The association between breastfeeding and improved cognitive ability had been long suspected and researched through observational studies; the new research is the first to examine the connection through a big, randomized trial.

And a recent report from the U.S. Centers for Disease Control (CDC) shows that more and more women are opting to breastfeed.

That bodes well for the future. But it's not to say, of course, that breastfeeding is the only option. I have known women for whom the discomfort of nursing was severe enough to cut that little experiment short. And some women just feel squeamish about the whole thing.

But many women who would like to nurse for the kind of prolonged period in the IQ study find it hard to maintain exclusive breastfeeding after they return to work. I will never forget the logistics and embarrassment associated with using a breast pump in the office -- and I worked in a very mom- and nursing-friendly place. Check out tomorrow's Health section for an article about the challenges women in D.C. face in trying to find private, clean spaces to express milk, despite the D.C. Council's December 2007 law requiring employers to provide such spaces.

Also coming tomorrow, in the On Parenting blog: three Post reporters review a new hands-free breast pump. Can't wait to see what they say!

I don't normally find yoga all that funny, except sometimes when I tip over during tree pose and fall in a heap on the floor. But then again, I've never tried laughter yoga.

Devised in India in the mid-1990s by Madan Kataria and brought to the U.S. by a handful of Kataria-trained teachers, laughter yoga aims to supply some of yoga's stress-relieving and other health benefits without the mats, bendy/stretchy poses and other trappings of more traditional brands of the ancient Indian tradition. Just like any yoga, though, it focuses on yoking breathing to bodily action, and it works the core muscles that help hold our tummies in and keep our low backs strong.

Laughter yoga's not about humor, unless you find the sight of a bunch of people standing around with their tongues stuck out funny. It starts by taking participants through a set of exercises designed to evoke ritualized, forced laughter; no joking involved. After a few minutes, the laughter tends to become more natural, and the emotions associated with laughing kick in. Folks who have done it report feeling happier, less stressed, and, yes, even more fit.

As to laughter yoga's proven health benefits, well, they're hard to pin down. Researchers have been examining the benefits of plain old laughter ever since Norman Cousins published his Anatomy of an Illness in 1979.

Maryland's got a handful of "laughter clubs" where you can give laughter yoga a try yourself. (Some opt not to use the word "yoga" but offer the same laughing exercises and experience.) Virginia and D.C. don't appear to have formally established clubs, but that doesn't mean there aren't groups of people out there, laughing together.

In fact, it turns out Maryland is kind of a hotbed of laughter/health research: Michael Miller, a cardiologist at the University of Maryland Medical Center, has done research showing that laughter may have beneficial cardiovascular effects, just as stress has been shown to adversely affect cardiovascular health.

And Richard Provine, a psychologist at the University of Maryland, Baltimore County, has established himself as an expert on the psychological benefits of yukking it up. He published his laughter-related research in 2000 in Laughter: A Scientific Investigation. Provine sees laughter as "a sign that things are going well in your life." And he notes, "It's a misperception that most laughter is in response to jokes. Laughter is social," he tells me. "It disappears in solitary people. If you're laughing, there are other people in your life."

But Provine says a lot of laughter research is biased by the researchers' desire to demonstrate that laughing is in fact good for you. In the end, he says, "The medical properties of laughter have been over-marketed. They may be attributable to the company you keep, not the laughter itself." In any case, Provine concludes, "If laughter feels good, isn't that enough?"

It's been a long week; I don't know about you, but I could use a laugh. Start with this John Cleese video, in which he explores laughter yoga in India.

When a woman gets pregnant, eating turns into a minefield . Swordfish for dinner? Nope, too much mercury. Blue cheese or feta on your salad? Sorry, soft cheeses can carry dangerous bacteria. A couple of glasses of wine with dinner? Forget about it.

Well, here's something that may sound too good to be true: If you're pregnant it looks like you should eat chocolate. Yup, chocolate.

Turns out chocolate appears to protect a pregnant woman from a serious complication of pregnancy known as preeclampsia. Preeclampsia is a common condition marked by high blood pressure and high levels of protein in the urine. It can be very dangerous -- even deadly -- for the mom and the baby.

The too-good-to-be-true news about chocolate comes from Elizabeth Triche of Yale University and her colleagues. The researchers studied 2,291 pregnant women who gave birth between 1996 and 2000. They asked the moms-to-be how much chocolate they ate in their first and second trimesters and tested blood from their umbilical cords for theobromine, a telltale component of chocolate.

Women who ate the most chocolate -- about a candy bar a day -- were about 70 percent less likely to develop preeclampsia than those who eat the least, the researchers report in this month's issue of the journal Epidemiology.

The findings mark the first time chocolate has been found to protect against preeclampsia. But they fit with earlier research indicating that chocolate is good for the heart, in part by reducing blood pressure. Dark chocolate appears to be the best, possibly because of substances known as flavanoids -- magnesum and theobromine.

Researchers need to do a lot more work to confirm their findings and figure out what exactly about chocolate is good. And the findings do not mean that pregnant women should pig out on chocolate: Gaining too much weight during pregnancy can lead to all sorts of problems. But Triche says if she was pregnant she'd eat a dark chocolate bar a day. It appears to help a woman get through those hard months in more ways than simply indulging her sweet tooth.

In the event of a flu pandemic or other large-scale medical disaster, who will decide which of us receives life-saving health care?

That's one of the big questions addressed in this report in the May issue of the journal Chest.

A task force set up to figure out how the medical communities in the U.S. and Canada can prepare to handle huge numbers of people suddenly requiring critical care made a set of recommendations on the training and equipment that would be required to respond to a large-scale emergency, be it an outbreak of SARS (the threat of which was a factor leading to the establishment of the task force) or an act of terrorism.

The report is straightforward and clinical, and it makes the case that planning and preparedness should go a long way in such a situation. But when it comes to the part about deciding, in the midst of a major, widespread emergency, how to allocate limited resources to save the greatest number of lives possible, even the dispassionate language can't stop a chill from running down my spine.

Should push come to shove, when even the best-prepared hospitals find their resources stretched, medical professionals may have to make tough decisions about whether to withhold or withdraw critical care from patients whose potential for long-term survival is low. This is grim: Patients with terminal cancer, dementia or a host of other grave conditions may be denied certain life-extending measures so that these can be administered to others with better long-term prospects.

The report emphasizes that palliative care -- pain-relief and comfort -- must be provided for all patients; nobody's going to be left to suffer unaided. But beyond that, doctors, nurses, and other health-care professionals are going to face some tough choices.

Even with a process in place, decisions are likely to be wrenching -- and memorable. Health section editor Frances Stead Sellers recalls

I remember my father talking about treating TB patients with antibiotics in British hospitals soon after the second World War. Streptomycin was a miracle cure, he remembered, but there simply wasn't enough to go around -- so the doctors had to make choices. Just think about having to perform that kind of triage in the baby ward: This one almost certainly lives; this one doesn't....

The report's recommendations are aimed in part at relieving care providers of the emotional, legal and ethical burdens such decisions might entail. Steve Gravely, a Richmond lawyer who deals in health-care issues and is familiar with the report, says "Everyone agrees that [in the event of a mass-casualty situation] we are not going to have enough resources to treat everyone the way we do today. As to where you go from there, there is no consensus."

"The emotional toll on doctors, nurses, and other health-care providers is going to be pretty significant," Gravely says. "Asking them to make these life-and-death decisions in a vacuum is asking a great deal." The report's recommendations, Gravely notes, should provide "psychological and emotional support for the medical staff. They know there's a process, and it doesn't all rest on their shoulders."

Gravely points out that the new report should serve as a "clarion call. Every hospital needs to be preparing for this right now."

Let's hope they are.

Imagine a world where nobody's allergic to peanuts.

Where passengers on planes could snack on peanuts; where parents wouldn't have to worry about their kids' gasping for air after taking a bite of a PB&J sandwich; where allergic kids wouldn't have to carry EpiPens everywhere they go -- and wouldn't have to learn how to stab themselves in the thigh to halt an allergic reaction. Where you could bring peanut-butter cookies to bake sales without fear that they'd make someone sick. And where manufacturers of candies and baked goods wouldn't have warn that their products were made in factories where peanuts were present.

That world -- or something like it, anyway -- could become real in just a few years, if a report in the current issue of The Lancet has got it right. Wesley Burks of the Duke University Medical Center writes that "It is likely that in the next five years there will be some type of immunotherapy available for peanut allergenic individuals."

Peanut allergies affect an estimated 1 percent of kids under 5; some develop skin rashes when exposed to peanuts, experience gastrointestinal problems, and still others suffer respiratory distress, which can be severe and even life-threatening.

For reasons unknown, the prevalence of peanut allergies among kids doubled between 1997 and 2002 and is thought to have continued to grow ever since. Some suspect the hygiene hypothesis, which postulates that our over-sanitized surroundings have reduced kids' opportunities to develop healthy immune responses to allergens, is in play here. (Read more about this notion in Rob Stein's dogs-versus-cats blog from last week.) Others suggest that pregnant or breast-feeding mothers' peanut-eating may trigger peanut allergies in their babies.

Not knowing the cause makes it harder for researchers to find a cure. But Burks and others are convinced that people with peanut allergies may soon find relief through immunotherapy, in which the allergic person is exposed to gradually-increased amounts of stuff that causes the allergic reaction, thereby building the person's tolerance for those allergens. This is a quintessential "don't try this at home" activity, by the way: because the consequences of exposure can be so dire, the whole process needs to be carefully orchestrated and monitored by physicians.

Burks also mentions efforts to engineer a new kind of peanut that's free of the various substances to which people have developed allergic reactions. But, he says in the study, "The process of altering enough of the peanut allergens to make a modified peanut that is less likely to cause an allergic reaction would probably render the new peanut no longer a peanut."

Five years must seem an eternity to folks dealing with peanut allergies every day of their lives. But at least there's hope.

Remember how great it felt to be, say, 17, cruising in a car with your buddies on a sunny spring day, the windows rolled down and the radio blasting?

And aren't you sometimes kind of surprised that you lived to tell the tale?

I know I am. And now that my own kids are fast approaching driving age, I'd do anything to keep them from being as blithely clueless as I was about the enormous risks associated with driving -- and about their own limited capacity to manage those risks.

It's hard to get inside a teen's head and figure out what they think about driving (or anything else, for that matter). But in an effort to find ways to better communicate information about the things that make driving so risky for youthful drivers and their passengers, researchers at the Children's Hospital of Philadelphia and State Farm Insurance did just that.

In a study published in the May issue of Pediatrics, 5,665 kids in grades 10-12 were asked to rate the riskiness of such behaviors as drinking, having unruly passengers, using cellphones and text messaging, and speeding, all of which we grownups know can pose grave risks to all drivers, including teens. The kids also were asked how often they'd witnessed such behaviors.

While many of the the teen respondents ranked lack of experience as a middling risk factor, they overwhelmingly reported that they'd rarely seen a teen driver who was inexperienced. The researchers note that teens likely equate "experience" with the mere fact of having acquired a license.

According to the teens, talking on a cellphone while driving wasn't all that risky, but text messaging was extremely risky, ranking right up there with racing other cars.

Having adolescent passengers barely registered as risky, but when those passengers start "acting wild," they become very risky indeed.

Nearly all the teens surveyed recognized drinking and driving as a very high-risk proposition, but very few reported having seen anyone drink and drive.

And while 70 percent of the teens said they wore seat belts, seat belt use ranked only at about the middle of the list of factors that make a big difference in driving safety.

Add to this research is the emerging brain imaging science that Laura Sessions Stepp will be writing about in a Health section article tomorrow. Turns out that our brains -- and particularly the parts associated with reasoning -- do not fully mature until we are in our mid-20s, making teenagers more vulnerable to impulsive decision making.

It's springtime once again. Time for teens to drive to the prom, to graduation parties, or just out with their buddies. Maybe now's a good time to ask our kids what they think about risky driving behaviors -- and to try to steer them toward mature ways to handle them.

Spring is in the air.

And so, apparently, is a lot of soot.

As was reported yesterday, the D.C./Baltimore/Northern Virginia area again has scored a spot in the American Lung Association's annual list of the top-10 cities with the filthiest air. Here's the full assessment.

On the bright side, the Lung Association notes that things are looking up: The D.C. region's air quality has improved over the past few years.

But we're still heading toward a long summer full of Code Orange and Code Red days when the air's so bad we're not supposed to breathe any more of it than we have to.

So, I was relieved to see that the Lung Association supplies this list of handy hints for reducing our exposure to the foul air around us (and, by extension, lessening our risk of lung disease, asthma, and other ills).

When I actually read the list, though, I was surprised to see that only a few tips are in fact aimed at helping individuals stay healthy: Check the weather report and plan to exercise indoors when pollution's at its worst; keep the kiddies inside when the smog is thick.

(And wait: Turns out the indoor air might be just as bad as the stuff outside, at least for folks with allergies or asthma. So say experts at the University of Missouri, who point out that our homes are filled with bad stuff to breathe, including dust mites, mold, and mildew, and who make these suggestions for cleaning up. For more in indoor air quality, check out the U.S. Environmental Protection Agency's indoor-air site.)

The rest of the "Tips to Protect Yourself" are all about keeping your own air-polluting activities to a minimum. That's great; we should all do our part. And in the long run, of course, those actions could help reduce everyone's risk from those grimy little pollutants that lodge in the lungs.

But calling "Combine trips and use buses, subways, light rail systems, commuter trains, or other alternatives to driving" a "tip to protect yourself" is a stretch. I, for one, would welcome something a bit more immediate -- and, yes, a little more self-serving. Should I be wearing a surgical mask on those steamy days when I walk the dog, or what?

For answers, I contacted the Lung Association and asked if they have anything more to offer.

Not much. Norman Edelman, the Lung Association's chief medical officer, says standard surgical masks don't do much to combat air pollution, as they're meant to "keep large droplets out," not the tiny particles of which air pollution is made. People with serious medical conditions (or who work around a lot of dust) can consider getting a special mask called an N95, which Edelman says you can buy at big hardware stores; even these need to be fitted properly to do any good. People who use inhalers, bronchodilators, or inhaled steroids might want to ask their doctors for extra doses to use on bad days, Edelman suggests. Air conditioners might help reduce the amount of ozone in your house, but their filters aren't all that efficient at removing particulate matter, he says; he also notes that if you use a room filter or whole-house filter, be sure it isn't one that actually produces ozone. And if you do choose to exercise, Edelman cautions, do it early in the morning or maybe late in the evening.

And that's about it.

Looks like it's going to be a very long summer.

FYI: With prom and graduation season upon us, I'll be blogging on Monday about the dangers of teen driving. In the meantime, check out ABC's prime-time special on the topic this coming Sunday at 7p.m. Then check in with The Checkup the next day.

We love all our pets. But are dogs better for your kids' health than cats? Say it ain't so!

Hate to be the one to break it to you. But a big new study is tilting the evidence toward the dog in the house.

How so? Well, it looks like your pooch is protecting your kids against more than just the mailman. Having a beagle, spaniel, lab or any old mutt seems to reduce the chances the kids will develop allergies.

Allergies? I know. This probably sounds counter-intuitive. After all, kids are often allergic to dogs, cats and other pets. But there's a growing body of research suggesting that children who spend lots of time around animals, like kids who grow up on farms, are less likely to get asthma, hay fever, eczema and other allergic diseases.

The theory is our furry four-legged friends expose children to dirt, microbes and more, training their developing immune systems not to overreact to pollen and other things that can cause allergies. I touched on this in a recent story about increases in both allergies and other immune system disorders.

The evidence, however, for which house pets are best for kids' immune systems has been mixed. Well, the big new study is the largest so far to focus on dogs.

Joachim Heinrich of the National Research Center for Environmental Health in Munich and his colleagues followed more than 6,000 children from birth until age 6. The researchers quizzed the kids' parents every year about whether they had asthma, hay fever, eczema or an other allergic diseases. The team also studied dust from their homes, and took blood samples when the children turned 6.

The kids who grew up with a dog were about 50 percent less likely to have antibodies to dust mites, pollen and other substances that commonly trigger allergies, the researchers reported this week in the European Respiratory Journal. That's a strong indication they'll be less likely to get allergies later in life. Now, it's not just having regular contact with a dog that appears to make the difference. Only kids who actually lived with one seemed to benefit.

So I know all you cat lovers are wondering: What about our beloved companions? An earlier study by Heinrich and some colleagues found no similar benefit from living with a feline. In fact, kids who had regular contact with kitties were more likely to develop one allergy -- to cats.