May 28th, 2010
04:22 PM ET

Public health pioneer on trail of "the next lead"

Doctors used to think that lead, like many dangerous substances, was only toxic beyond a certain threshold. That changed thanks to a landmark study by Dr. Philip Landrigan, whose findings inspired a federal ban on lead in paint and gasoline. Today he is a principal investigator with the National Children’s Study, a mammoth undertaking by the National Institutes of Health that aims to follow 100,000 children from before birth to age 21, to identify the health effects of toxic exposures and other factors. He spoke with Dr. Sanjay Gupta.

Dr. Sanjay Gupta: Does it usually start off with a hypothesis on your part? Are you literally thinking, “I think there is a connection between this chemical and this problem?

Dr. Philip Landrigan: I think if you take the long view, it actually usually begins with clinical observation. A doctor somewhere who's smart and astute observes that the children who are exposed to a particular chemical are having problems. That's what happened 100 years ago when childhood lead poisoning was first recognized, in Australia. It's what happened 50 years ago when methyl-mercury poisoning was first recognized in Japan, at a village called Minamata. These were situations of acute, high-dose exposure, and smart clinicians recognized the connection between the exposure and the disease. Sometimes a lot of detective work was involved. Once the connection is established by an astute clinician, then hypothesis become part of the story. A number of years ago, we said, “We know that high-dose exposure causes devastating injury to the brain, with coma, with convulsions, with various, very severe clinical manifestations. Might it not be possible that a lower dose also causes dysfunction?” But that dysfunction requires more specialized testing to recognize.

Gupta: When you're talking about cause and effect, are there things now that in 10 to 20 years, kids will come to us and say, “When did you first start to suspect that X was a problem?” Are there things right now that in the back of your mind where you're thinking, “I can't prove this yet, but I'm pretty convinced that this it's going to be a problem and it's causing [problems] in kids?

Landrigan: Well I think one very important class of chemicals that falls squarely in that category today are the phthalates. Phthalates are a type of chemical that falls under the broad category of plastics chemicals. They're added to a lot of rigid plastics, like polyvinyl chloride, to make them flexible. Other phthalates are widely used in cosmetics, skin creams and the like, and they penetrate into people's bodies through the skin. Investigators in our department at Mount Sinai School of Medicine of New York have just recently published a paper in one of the peer reviewed medical journals, which showed that babies who were exposed in the womb to phthalates – six or seven years ago – are now, at age seven, showing aberrations in behavior that look very much like attention deficit disorder. This is obviously something that has to be corroborated; this is just one study. But we're all exposed to phthalates, and if this finding holds up, we've got a problem that we've got to do something about.

Gupta: What is the reaction to the sort of work that you do, within the medical community?

Landrigan: I think there's growing appreciation for this work. You know, historically, most medical students have had very little training in environmental medicine. The average is about four or five hours, in most medical schools across the country. And so most doctors know about lead poisoning; most doctors know about the environmental triggers of asthma, but beyond that their knowledge base is a little thin, and often they don't have much appreciation for environmental problems.

For more of Dr. Gupta’s conversation with Dr. Landrigan, watch “Sanjay Gupta, MD,” Saturday and Sunday at 7:30 a.m., ET.

May 28th, 2010
12:45 PM ET

Brush your teeth, save your heart?

By Madison Park
CNNhealth.com writer/producer

It’s not only tartar build-up and nasty gum diseases you have to worry about. If you don’t brush your teeth twice a day, you’re more likely to develop heart disease, says a new British study.

Someone tell Jessica Simpson.

Earlier this month, the pop singer and sometimes-actress, told Ellen DeGeneres that she  brushes her teeth only about three times a week, because she doesn’t like them to “feel too slippery.”

“I don’t brush them everyday. I’ll use a shirt or something ... I know it's gross, but I always have fresh breath," she said.  Simpson added that she's a big fan of Listerine and floss.

So keep in mind - just because they’re pearly and sheen, it doesn’t mean they’re clean.

Other ways you might be ruining your teeth

The study published Friday in the British Medical Journal found that individuals with poor oral hygiene have a 70 percent increased risk of heart disease compared with people who brush twice daily. Read research here

This adds to existing research that shows having bad oral hygiene can lead to  problems, including inflammation that could clog arteries.

Researchers from the University College London analyzed data from a Scottish health survey, looking at responses from 11,000 adults about smoking, physical activity and oral health routine – including how often they visited the dentists and brushed their teeth. Their family and personal medical histories, blood pressure and samples were taken, too.

About 71 percent reported brushing their teeth twice a day and 62 percent said they visit a dentist twice a year*.  Those with poor oral hygiene  had higher risk of heart disease and also tested positive for inflammatory markers such as the C-reactive protein and fibrinogen.

People magazine interviewed Simpson’s dentist, Dr. Bill Dorfman, who was surprised to hear his patient did not brush twice a day.

"It's great that she’s flossing all the time, but you have to brush too," Dorfman told People. "What goes on in your mouth really affects your whole body."

[*An earlier version of this post incorrectly stated the frequency of dental visits by people in the study.]

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About this blog

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.