Two components of red meat combined with alteration in DNA repair increase risk for bladder cancer

ScienceDaily (Oct. 17, 2012) — Two components of red meat -- dietary protein and dietary iron -- may combine to form powerful carcinogens, N-nitroso compounds, which increase risk for bladder cancer. Moreover, individuals with reduced ability to reverse the effects of N-nitroso compounds because of a genetic variation in their RAD52 gene could be at particularly high risk.

Chelsea Catsburg, a doctoral student at the Keck School of Medicine of the University of Southern California, Los Angeles, presented these data at the 11th Annual AACR International Conference on Frontiers in Cancer Prevention Research, held in Anaheim, Calif. Oct. 16-19, 2012.

Dietary protein is made up of amino acids, which can be naturally metabolized into biogenic amines, according to Catsburg. Research has shown that the processing and storage of meat increases amine concentrations. When these amines are in the presence of nitrites, they generate nitrosamines, which have carcinogenic properties. In addition, heme iron, found in red meat, has been shown to increase the formation of nitrosamines from amines.

"Nitrosamine formation occurs predominantly in the stomach and intestines, so these exposures have been studied extensively in relation to gastric cancer and somewhat in relation to colorectal cancer," Catsburg said. "However, there is evidence that these reactions also take place in the bladder, particularly in the presence of infection."

Catsburg and colleagues had previously found that meat groups with high heme and high amine concentrations, such as salami and liver, increased risk for bladder cancer. In this study, they examined whether genetic variation in DNA repair enzymes, available to correct the damage caused by these endogenously formed carcinogens, modified these associations.

The researchers tested 627 single-nucleotide polymorphisms in 27 genes involved in N-nitroso compound metabolism or DNA repair. They collected data from 355 bladder cancer cases and 409 controls in the Los Angeles Bladder Cancer Study.

"We found that a polymorphism in the RAD52 gene modified the effect of these exposures," Catsburg said. "This polymorphism is suspected to reduce the DNA repair activity of the RAD2 protein, and the association of these meat groups and bladder cancer risk was significantly higher in individuals with one or more copies of this polymorphism."

These results further support recommendations by the World Cancer Research Fund to limit red meat intake and to avoid processed meats to reduce risk for stomach and bowel cancer, according to the researchers.

"This study suggests that these exposures may also affect secondary organs such as the bladder," Catsburg said. "Individuals at risk for bladder cancer may wish to avoid intake of red and processed meats, especially if they have genetic polymorphisms that reduce DNA repair activity and make them more vulnerable to the effects of carcinogens."

Further replication of this study to support an association between heme and meat intake and the risk for bladder cancer is necessary, she added.

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The above story is reprinted from materials provided by American Association for Cancer Research (AACR).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

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Value of combined approach to quitting smoking confirmed

ScienceDaily (Oct. 18, 2012) — Smokers who try to quit would be more successful if they combined medication or nicotine-replacement therapy with behavioral counseling, finds a new review in The Cochrane Library. Few lifestyle changes deliver as many positive health benefits as quitting smoking, including improved circulation, lowered blood pressure and a decreased risk of cancer and heart disease.

"Since we know that both types of treatment are effective, the assumption has certainly been that offering both will be better than offering either alone," said lead researcher Lindsay Stead of the department of primary health care sciences at the University of Oxford. She and her coauthor sought to confirm this observation by measuring the effects of combining behavioral and medication therapy versus no intervention or medication therapy alone. The reviewers pooled findings from 41 studies involving more than 20,000 smokers.

The review found that providing a combination of medication and behavioral therapy improved quit rates by as much as 70 to 100 percent compared to no treatment or minimal intervention. Behavioral therapy interventions typically included four to eight sessions with smoking cessation counselors or physicians. "Health care providers have an important role in convincing smokers of the importance of attempting to quit and making pharmacotherapy and behavioral support available," the researchers stated.

"Usual care in most health care systems for smoking cessation typically consists of brief pre-quit counseling, a recommendation to use, and possible provision of cessation medication, and a follow-up visit or phone call a few weeks later," said Stevens S. Smith, Ph.D., associate professor in the department of medicine at the University of Wisconsin's Center for Tobacco Research and Intervention.

"For patients motivated to make a quit attempt, counseling and assistance with medications -- if medically appropriate -- should be provided," said Smith. "For patients not motivated to quit, the doctor should use motivational interventions. Another option is referral to tobacco quit lines, such as 1-800-QUIT-NOW, where smokers can receive free medication, counseling, and other support to quit smoking."

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The above story is reprinted from materials provided by Health Behavior News Service, part of the Center for Advancing Health. The original article was written by Joan Vos MacDonald.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Lindsay F Stead, Tim Lancaster. Combined pharmacotherapy and behavioural interventions for smoking cessation. Cochrane Database of Systematic Reviews, 2012 DOI: 10.1002/14651858.CD008286.pub2

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Value of combined approach to quitting smoking confirmed

ScienceDaily (Oct. 18, 2012) — Smokers who try to quit would be more successful if they combined medication or nicotine-replacement therapy with behavioral counseling, finds a new review in The Cochrane Library. Few lifestyle changes deliver as many positive health benefits as quitting smoking, including improved circulation, lowered blood pressure and a decreased risk of cancer and heart disease.

"Since we know that both types of treatment are effective, the assumption has certainly been that offering both will be better than offering either alone," said lead researcher Lindsay Stead of the department of primary health care sciences at the University of Oxford. She and her coauthor sought to confirm this observation by measuring the effects of combining behavioral and medication therapy versus no intervention or medication therapy alone. The reviewers pooled findings from 41 studies involving more than 20,000 smokers.

The review found that providing a combination of medication and behavioral therapy improved quit rates by as much as 70 to 100 percent compared to no treatment or minimal intervention. Behavioral therapy interventions typically included four to eight sessions with smoking cessation counselors or physicians. "Health care providers have an important role in convincing smokers of the importance of attempting to quit and making pharmacotherapy and behavioral support available," the researchers stated.

"Usual care in most health care systems for smoking cessation typically consists of brief pre-quit counseling, a recommendation to use, and possible provision of cessation medication, and a follow-up visit or phone call a few weeks later," said Stevens S. Smith, Ph.D., associate professor in the department of medicine at the University of Wisconsin's Center for Tobacco Research and Intervention.

"For patients motivated to make a quit attempt, counseling and assistance with medications -- if medically appropriate -- should be provided," said Smith. "For patients not motivated to quit, the doctor should use motivational interventions. Another option is referral to tobacco quit lines, such as 1-800-QUIT-NOW, where smokers can receive free medication, counseling, and other support to quit smoking."

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Health Behavior News Service, part of the Center for Advancing Health. The original article was written by Joan Vos MacDonald.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Lindsay F Stead, Tim Lancaster. Combined pharmacotherapy and behavioural interventions for smoking cessation. Cochrane Database of Systematic Reviews, 2012 DOI: 10.1002/14651858.CD008286.pub2

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Two components of red meat combined with alteration in DNA repair increase risk for bladder cancer

ScienceDaily (Oct. 17, 2012) — Two components of red meat -- dietary protein and dietary iron -- may combine to form powerful carcinogens, N-nitroso compounds, which increase risk for bladder cancer. Moreover, individuals with reduced ability to reverse the effects of N-nitroso compounds because of a genetic variation in their RAD52 gene could be at particularly high risk.

Chelsea Catsburg, a doctoral student at the Keck School of Medicine of the University of Southern California, Los Angeles, presented these data at the 11th Annual AACR International Conference on Frontiers in Cancer Prevention Research, held in Anaheim, Calif. Oct. 16-19, 2012.

Dietary protein is made up of amino acids, which can be naturally metabolized into biogenic amines, according to Catsburg. Research has shown that the processing and storage of meat increases amine concentrations. When these amines are in the presence of nitrites, they generate nitrosamines, which have carcinogenic properties. In addition, heme iron, found in red meat, has been shown to increase the formation of nitrosamines from amines.

"Nitrosamine formation occurs predominantly in the stomach and intestines, so these exposures have been studied extensively in relation to gastric cancer and somewhat in relation to colorectal cancer," Catsburg said. "However, there is evidence that these reactions also take place in the bladder, particularly in the presence of infection."

Catsburg and colleagues had previously found that meat groups with high heme and high amine concentrations, such as salami and liver, increased risk for bladder cancer. In this study, they examined whether genetic variation in DNA repair enzymes, available to correct the damage caused by these endogenously formed carcinogens, modified these associations.

The researchers tested 627 single-nucleotide polymorphisms in 27 genes involved in N-nitroso compound metabolism or DNA repair. They collected data from 355 bladder cancer cases and 409 controls in the Los Angeles Bladder Cancer Study.

"We found that a polymorphism in the RAD52 gene modified the effect of these exposures," Catsburg said. "This polymorphism is suspected to reduce the DNA repair activity of the RAD2 protein, and the association of these meat groups and bladder cancer risk was significantly higher in individuals with one or more copies of this polymorphism."

These results further support recommendations by the World Cancer Research Fund to limit red meat intake and to avoid processed meats to reduce risk for stomach and bowel cancer, according to the researchers.

"This study suggests that these exposures may also affect secondary organs such as the bladder," Catsburg said. "Individuals at risk for bladder cancer may wish to avoid intake of red and processed meats, especially if they have genetic polymorphisms that reduce DNA repair activity and make them more vulnerable to the effects of carcinogens."

Further replication of this study to support an association between heme and meat intake and the risk for bladder cancer is necessary, she added.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by American Association for Cancer Research (AACR).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here