Friday, June 3, 2011

Cell Phones Might Cause Brain Cancer

May 31, 2011 -- The expert panel that evaluates cancer risks today said that cell phones might possibly cause brain cancer.

The announcement comes from the International Agency for Research on Cancer (IARC). Like the World Health Organization, the American Cancer Society relies on IARC for evaluation of cancer risks.

"After reviewing all the evidence available, the IARC working group classified radiofrequency electromagnetic fields as possibly carcinogenic to humans," panel chairman Jonathan Samet, MD, chair of preventive medicine at the USC Keck School of Medicine, said at a news teleconference. "We reached this conclusion based on a review of human evidence showing increased risk of glioma, a malignant type of brain cancer, in association with wireless phone use."

In finding cell phones to be "possibly carcinogenic," the IARC means that heavy cell phone use might -- or might not -- cause a specific form of brain cancer called glioma. The finding means that research is urgently needed to find out whether cell phones actually cause cancer, and how they might do it.

The IARC estimates that some 5 billion people worldwide have mobile phones. Lifetime exposure to the magnetic fields created by the phones -- particularly when they are held tightly against the head -- rapidly is increasing.

Children are at particular risk, not only because their skulls are thinner but also because their lifetime exposure to cell phones likely will be greater than the exposure of current adults.
 
Putting Possible Cancer Risk in Perspective

It's important to put the possible risk into context. Kurt Straif, MD, PhD, MPH, head of the IARC Monographs Program, notes that the IARC currently lists some 240 agents as "possibly carcinogenic," including dry cleaning fluid and some commonly used pesticides.

While the IARC doesn't make recommendations to consumers, Straif noted that there are precautions people can take.

"Some of the highest exposures come from using mobile phones for voice calls. If you text, or use hands-free devices, you lower exposure by at least [10-fold]," Straif said at the news conference. "So this is left to consumers to consider whether this level of evidence is enough for them to take such precautions."

Otis W. Brawley, MD, chief medical officer for the American Cancer Society, notes that the IARC is a highly credible group. But Brawley echoes Straif's advice: People who are worried can reduce their risk.

"On the other hand, if someone is of the opinion that the absence of strong scientific evidence on the harms of cell phone use is reassuring, they may take different actions, and it would be hard to criticize that," Brawley says in a news release.

John Walls, vice president for public affairs at CTIA, the trade group representing the wireless communications industry, notes that the IARC findings do not mean cell phones cause cancer -- and that the limited evidence on which the findings are based are far from conclusive.

"Based on previous assessments of the scientific evidence, the Federal Communications Commission has concluded that '[t]here's no scientific evidence that proves that wireless phone usage can lead to cancer.' The Food and Drug Administration has also stated that '[t]he weight of scientific evidence has not linked cell phones with any health problems,'" Walls notes in a news release.

Samet and colleagues will publish a summary of their findings in the July 1 issue of The Lancet, which is still in press.

SOURCES: IARC, news teleconference, May 31, 2011American Cancer Society, news release.News release, CTIA-The Wireless Association.International Agency for Research on Cancer web site.News release, International Agency for Research on Cancer.Jonathan Samet, MD, chair of preventive medicine, USC Keck School of Medicine.Kurt Straif, MD, PhD, MPH, head, International Agency for Research on Cancer Monographs Program. ©2011 WebMD, LLC. All Rights Reserved.
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Eating Meat May Raise Colon Cancer Risk


Study Suggests Eating Less Red Meat and Processed Meat May Cut Chances of Getting Colon Cancer.

May 23, 2011 -- Red meat and processed meat may increase the risk of developing colon cancer, according to a new report from the American Institute for Cancer Research (AICR) and the World Cancer Research Fund.

The report, which builds on the two groups' 2007 Continuous Update Project, points to solid evidence that eating less red meat and avoiding processed meat altogether can slash colon cancer risk.

When this advice is combined with other diet and lifestyle changes -- such as consuming less alcohol, boosting fiber intake, exercising, and maintaining a healthy body weight -- it could prevent 45% of all colon cancer cases, or more than 64,000 cases of colon cancer each year, the report states.

Colorectal cancer is the third most common type of cancer diagnosed in the U.S., excluding skin cancers, according to the American Cancer Society.

"The good news is that we have some control over our colon cancer risk," says Elisa Bandera, MD, PhD, an associate professor of epidemiology, Cancer Institute of New Jersey, New Brunswick. Bandera was a member of the expert panel that analyzed all of the available literature on colon cancer risk, diet, exercise, and weight.

Eating less than 18 ounces per week of red meat, such as beef, lamb, or pork, shows very little increase in colon cancer risk, the report states.

People who eat 3.5 ounces or red meat every day (24.5 ounces per week) will have a 17% increased risk of colon cancer compared to someone who eats no red meat, according to the report. People who eat 7 ounces per day (49 ounces per week) will have a 34% increased risk.

People who eat 3.5 ounces of processed meat a day will have a 36% increased risk of developing colon cancer compared with people who avoid all processed meat, according to the report. The more processed meat eaten, the higher your risk for developing colorectal cancer.

Why Meat May Raise Colon Cancer Risk
Exactly how red and/or processed meat increases risk for colon cancer isn't clear, but there are several theories. Some research suggests that chemicals called heterocyclicamines,which are produced when meat is cooked at high temperature, may play a role. Processed meats are made by smoking, curing, salting, and or adding preservatives such as nitrates. The body converts nitrates into nitrosamines, which are known to increase risk of cancer.

"It appears that red meat -- and maybe processed meat even more -- has some relationship with colon cancer risk," says panel member Steven H Zeisel, MD, PhD, theKenan Distinguished Professor of nutrition and pediatrics at the University of North Carolina, Chapel Hill.

"A betting person would say there is risk associated with the consumption of red meat and processed meat," he says. "Moderating the amount of red meat you take in is reasonable based on this data. And trying to cut back and substitute other types of meat or vegetables would be a good idea for someone who wants to reduce risk of colon cancer."

Diet and Lifestyle Changes
Drinking alcohol may increase colon cancer risk, according to the report. The report also states that excess belly fat may raise colorectal cancer risk, but staying lean, eating more fiber, and engaging in regular physical activity can help lower this risk.

"If you limit consumption of red meat, you have more room on your plate for good things like whole grains and vegetables," Bandera says. Some simple substitutes can help. "Choosing brown rice instead of white rice is a good way of increasing fiber."

Alice Bender, MS, RD, of the AICR, says the new report is especially important to people with a family history of colorectal cancer.

"If you have family history, it's more important than ever to follow these guidelines because they offer potentially some extra protection," she says.

National Cattlemen's Beef Association Weighs In
"Americans should continue to build healthier diets with beef, knowing the scientific evidence to support the role of nutrient-rich, lean beef in a healthy, balanced diet is strong," says Shalene McNeill, PhD, RD, executive director of Human Nutrition Research at the National Cattlemen's Beef Association.

"Nothing in this update should change the way Americans consume beef," she says. " In fact, Americans are consuming beef well within WCRF's [World Cancer Research Fund] 500 gram (18 ounces) per week recommendation. As a scientist, registered dietitian, and a mother, I will continue to recommend lean beef to Americans trying to build a healthier plate because of the unique package of nutrients and enjoyment it brings to a healthy diet."

SOURCES: Elisa Bandera, MD, PhD, associate professor, epidemiology, Cancer Institute of New Jersey, New Brunswick.Steven H Zeisel, MD, PhD, Kenan Distinguished Professor ofnutrition and pediatrics, University of North Carolina, Chapel Hill.Alice Bender, MS, RD, American Institute for Cancer Research, Washington, D.C.World Cancer Research Fund/American Institute for Cancer Research: "Continuous Update Project Report," May 23, 2011.Shalene McNeill, PhD, RD, executive director of Human Nutrition Research, National Cattlemen's Beef Association. ©2011 WebMD, LLC. All Rights Reserved.
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