Obesity growing to be top cancer cause
Fri, 15 Feb 2008 22:22:21 GMT
By RANDOLPH E. SCHMID, AP Science Writer
BOSTON - Obesity is on its way to being deadlier than smoking as a cause of cancer, a leading researcher said Friday. Being obese is currently associated with about 14 percent of cancer deaths in men and 20 percent in women, compared with about 30 percent each for smoking, Dr. Walter C. Willett of the Harvard School of Public Health, told the annual meeting of the American Association for the Advancement of Science.
"As smoking goes down and obesity goes up it won't be long before obesity is the No. 1 cancer killer," Willett said at a symposium on cancer prevention.
Added Dr. Douglas R. Lowy of the National Cancer Institute: "Cancer prevention begins at home. ... Not all of us always act in our own best interest."
Willett said research is producing increasing evidence associating obesity with a variety of cancers, including breast, colorectal, liver, pancreas and gallbladder. Alcohol is also associated with certain cancers, he said.
In the 1980s, researchers focused on the amount of fat people ate as a probable cause of cancer, but studies did not strongly support that. Later they turned to diets high in fruits and vegetables as a way to reduce cancer, but again, Willett said, they struggled to find convincing evidence in studies.
Now attention has turned to obesity, and more and more research is providing evidence that indict that as a cancer cause.
That does not mean people should stop eating fruit and vegetables and go to a high-fat diet, he quickly added. "We do see evidence of a benefit for heart disease, I think that's pretty real," he said.
And, he noted, studies have indicated some benefit from a high
fruit and vegetable diet in some cancers, he added, including mouth, esophagus, lung and stomach.
Overall, Willett estimated 30 percent to 35 percent of cancers are due to nutritional factors, much of it to obesity.
Being overweight may raise cancer risk
Fri, 15 Feb 2008 22:53:38 GMT
By MARIA CHENG, AP Medical Writer
LONDON - Being obese or even overweight may increase a person's risk of developing up to a dozen different types of cancer, European researchers report in a new study.
Doctors have long suspected a link between weight gain and certain cancers, including colon and breast cancers. But the new study, published Friday in the journal Lancet, suggests it could also increase chances for cancer of the esophagus, thyroid, kidney, uterus and gall bladder, among others.
While the study suggests a link, there is no definitive proof that being fat in itself causes cancer.
"To make the link between cause and effect, we need to tick several boxes," said Dr. Andrew Renehan, the study's lead author and senior lecturer at the School of Cancer Studies at the
University of Manchester. "This study begins to tick the first two or three boxes, but more research is needed to confirm it."
The researchers compiled data from 141 studies and considered more types of cancers and more diverse populations than had been done previously. The research covered more than 280,000 cases from North America, Europe, Australia and Asia.
The subjects, both overweight and normal weight, were followed for about nine to 15 years, with researchers tracking their body mass index, or BMI — a calculation based on weight and height — and correlating it with incidents of cancer.
In men, an average weight gain of 33 pounds increased the risk of esophageal cancer by 52 percent, thyroid cancer by 33 percent, and colon and kidney cancers each by 24 percent, the research found.
In women, a weight gain of 29 pounds increased the risk of cancer in the uterus and gall bladder by nearly 60 percent, esophagus by 51 percent and kidney by 34 percent, the study said.
The link was weaker for bone and blood cancers, for both men and women.
In Asian populations, there appeared to be a stronger link between increased BMI and breast cancer, the study said.
"This study provides a lot of circumstantial evidence about the dangers of obesity," said Dr. David Robbins, a gastroenterologist at
Beth Israel Medical Center in
New York, who was not involved in the study. "It also highlights the cancer crisis we face as obesity rates increase worldwide."
Scientists are unsure how being overweight could make people more susceptible to cancer.
"One of the hypotheses is that the presence of excess fat cells could affect the levels of hormones in your body," Renehan said. "At a cellular level, that may favor the development of tumors in humans."
Because many studies have found that fatter people are more likely to get cancer, experts often recommend losing weight to reduce cancer risk.
"The simple message is that, if you manage to keep a healthy body weight, you will have a lower risk of developing cancer," said Ed Yong, of Cancer Research
United Kingdom.
The Lancet study was paid for by British Medical Association, the
University of Manchester and the University of Bern, Switzerland. Renehan has consulted for several pharmaceutical companies that make hormone replacements.
CDC Death count 82 for choking game
Fri, 15 Feb 2008 22:53:51 GMT
By MIKE STOBBE, AP Medical Writer
ATLANTA - At least 82 youths have died from the so-called "choking game," according to the first government count of fatalities from the tragic fad.
In the game, children use dog leashes or bungee cords wrapped around their necks or other means to temporarily cut blood flow to their head. The goal is a dreamlike, floating-in-space feeling when blood rushes back into the brain.
As many as 20 percent of teens and preteens play the game, sometimes in groups, according to estimates based on a few local studies. But nearly all the deaths were youths who played alone, according to the count compiled by the
U.S. Centers for Disease Control and Prevention.
The
CDC started the research after receiving a letter last year from a
Tacoma, Wash., physician who said her 13-year-old son died from playing the game in 2005.
"At the time I had never heard of this," said Dr. Patricia Russell, whose son was found hanging in his closet, but later learned he had talked to a friend about it.
"One thing that really needs to happen — and is starting to happen now — is to get more information about how common this is," she said.
The CDC counted cases from news reports and advocacy organizations in the years 1995 through 2007, totaling 82 fatalities of children ages 6 to 19. They did not include deaths in which it was unclear if the death was from the choking game or if it was a suicide. They also did not include deaths that involved autoerotic asphyxiation, which is self-strangulation during masturbation and is said to be mainly done by teenage boys or men.
The 82 deaths were spread across 31 states. Nearly 90 percent were boys, at an average age of about 13, the CDC found.
Three or fewer deaths were reported from 1995 through 2004. They jumped to 22 in 2005, 35 in 2006 and at least nine in 2007. It's not clear what drove the increase in recent years, investigators said.
The report is being published this week in a
CDC publication, Morbidity and Mortality Weekly Report.
CDC officials urged parents to be aware the fad exists, and to watch for possible warning signs like bloodshot eyes, marks on the neck, frequent and severe headaches, disorientation after spending time alone, and ropes, scarves or belts tied to bedroom furniture or doorknobs or found knotted on the floor.
The authors acknowledged that 82 is probably an undercount. They could not rely on death certificates, which do not differentiate choking-game deaths from other unintentional strangulation deaths. Instead, they relied mainly on a news database that is large but doesn't include all media outlets.
It's likely that there are about 100 U.S. choking game deaths each year, said Dr. Tom Andrew,
New Hampshire's chief medical examiner, who has been studying the phenomenon for several years.
Andrew said many coroners and medical examiners likely label the deaths as suicides because they don't have the time or resources to interview a victim's friends and look for alternate explanations.
Many of the children who died from the choking game were described as bright, athletic students who apparently were intrigued by a method of getting high that doesn't involve drugs or alcohol, he said.
They watch it on
YouTube, or hear about it in school or at summer camp, said Sharron Grant, a Canadian woman who was a founder of an advocacy group called Games Adolescents Shouldn't Play .
Choking game fatalities are not nearly as common as suicide deaths among youths who choose hanging or suffocation. About 5,100 such suicide deaths were reported from 1995 through 2007, and while it's possible some were unrecognized choking game deaths, most were believed to be actual suicides, said Robin Toblin, a
CDC epidemiologist.
The game is also known by names that include "blackout," "space monkey" and "pass out," Toblin and others said.
Variations of the game have been around for decades, but the trend of doing it alone seems to be recent, Andrew said.
___
On the Net:
The
CDC publication: http://www.cdc.gov/mmwr
