Soft Drinks Could Boost Pancreatic Cancer Risk

MONDAY, Feb. 8 (HealthDay News) — People who down two or more soft drinks a week may have double the risk of developing deadly pancreatic cancer, compared to non-soda drinkers, new research suggests.

But the overall number of people developing the malignancy remains low, with the U.S. National Cancer Institute (NCI) estimating 42,470 new cases last year.

“Soft drinks are linked with a higher risk of pancreatic cancer,” said Noel Mueller, lead author of a study appearing in the February issue of Cancer Epidemiology, Biomarkers & Prevention. “We can’t speculate too much on the mechanism because this is an observational study, but the increased risk may be working through effects of the hormone insulin.”

Still, the report should not cause undue alarm, some say.

“The study was well designed but smaller than some previous studies that did not find a link between sugar-sweetened soft drinks and pancreatic cancer,” noted Eric Jacobs, strategic director of pharmacoepidemiology at the American Cancer Society. “Direct evidence linking sugar-sweetened soft drinks to pancreatic cancer remains limited.”

And adult soda drinkers may also engage in other lifestyle habits, such as smoking, which could contribute to the elevated risk.

“It’s an interesting finding but if you look at the people who had the high soft drink intake, they also had other issues that may also predispose you to pancreatic cancer,” said Dr. Colin D. Weekes, assistant professor of medicine at the University of Colorado Denver. “It’s hard to make any true associations from this. “We could argue that smoking could be the issue here and not the soda intake.”

Although the study didn’t differentiate between regular and diet soda, it was conducted in Singapore, where most soda consumed is regular, Mueller said.

The study was a collaboration between the University of Minnesota and National University of Singapore. Mueller, formerly at Minnesota, has since joined Georgetown University Medical Center in Washington, DC, as a research associate.

The analysis involved more than 60,000 middle-aged or older Chinese Singaporeans. Researchers calculated how much juice and soda the participants drank on average and followed them for 14 years to see how many developed cancer of the pancreas.

Those who drank two or more sodas a week were 87 percent more likely to develop this kind of tumor than individuals who didn’t consume any soda.

Researchers found no link between juice consumption and cancer risk, perhaps because fruit juice has less effect than sugary sodas on glucose and insulin levels, the authors noted.

Previous research in U.S. and European populations has suggested an association between sweetened sodas and juices and pancreatic cancer. This is the first study to examine the association in an Asian population, although the authors feel the findings can be extrapolated to Western nations.

“We believe that because Singaporean adults have a lot of the same mannerisms as Western countries, which is a tendency to eat fast food and also go shopping, one could say that these findings may be generalizable to other Western countries,” said Mueller. “Genetically they are very different from Caucasians, however their lifestyle is similar to Western countries.”

The findings are biologically plausible.

Type 2 diabetes, a disorder of blood sugar levels and insulin under-activity, has also tentatively been linked to pancreatic cancer.

The researchers speculate that elevated blood sugar levels associated with soda-drinking and the associated increase in insulin levels prompt pancreatic cells to divide abnormally.

“Drinking sugar-sweetened soft drinks has been linked to weight gain, obesity and diabetes. Both obesity and diabetes are associated with higher risk of pancreatic cancer, one of the leading causes of cancer death in the United States,” Jacobs said.

The soft drink industry disputed the findings, however.

“The [study] authors are skipping several steps in trying to connect soft drinks with pancreatic cancer, including an allegation regarding an increase in insulin production,” Richard Adamson, a consultant to the American Beverage Association and former scientific director of the NCI, said in a statement.

“The fact remains that soft drinks do not cause cancer, nor do any authoritative bodies, such as NCI, name soft drinks as a risk factor for pancreatic cancer,” he added. “You can be a healthy person and enjoy soft drinks. The key to a healthy lifestyle is balance — eating a variety of foods and beverages in moderation along with getting regular physical activity,” Adamson added.

Others took a more cautious view.

“The bottom line is that limiting consumption of sugar-sweetened soft drinks can help in maintaining a healthy weight, which in turn will reduce risk of many types of cancer and other serious diseases,” Jacobs said.

source: news.health.com

Third-hand smoke a danger to babies, toddlers

Residue of nicotine can interact with chemical in air to form carcinogens

Add a new health threat to smoking: In addition to the harm caused by actually smoking and exposure to second-hand smoke, so-called third-hand smoke may also pose a threat, particularly to babies and toddlers.

A new study reveals that the residue of nicotine that lingers on surfaces can react with another chemical in the air to form potent carcinogens — chemicals linked to various cancers. While first-hand smoke is that inhaled directly by the smoker and second-hand is the smoke exhaled (and inhaled by others), third-hand smoke is the residue from second-hand smoke.

Anyone who has entered a confined space — a room, an elevator, a vehicle, etc. — where someone has recently been smoking, knows that the scent lingers for an extended period of time.

"The burning of tobacco releases nicotine in the form of a vapor that adsorbs strongly onto indoor surfaces, such as walls, floors, carpeting, drapes and furniture. Nicotine can persist on those materials for days, weeks and even months," said Hugo Destaillats, a chemist with Lawrence Berkeley National Laboratory in San Francisco, and one of the authors of the study.

Scientists have been aware for several years that tobacco smoke sort of sticks to surfaces where it can react with other chemicals. But reactions of residual smoke constituents with molecules in the air have been overlooked as a source of harmful pollutants, the researchers of the new study say.

Destaillats and colleagues investigated the formation of harmful chemicals in the air after exposing material to cigarette smoke. They found that it reacts with one chemical in particular.

"Our study shows that when this residual nicotine reacts with ambient nitrous acid it forms carcinogenic tobacco-specific nitrosamines or TSNAs," Destaillats said. "TSNAs are among the most broadly acting and potent carcinogens present in unburned tobacco and tobacco smoke."

Unvented gas appliances are the main source of nitrous acid indoors.

The researchers used cellulose as a model of indoor material, and exposed it to cigarette smoke. They then exposed it to a "high but reasonable" concentration of nitrous acid for three hours. The levels of newly formed TSNAs were 10 times higher after the nitrous acid exposure. The TSNAs also formed quickly, the researchers found.

"Given the rapid sorption and persistence of high levels of nicotine on indoor surfaces, including clothing and human skin, our findings indicate that third-hand smoke represents an unappreciated health hazard through dermal exposure, dust inhalation and ingestion," said lead author Mohamad Sleiman, also of Berkeley Lab.

Since most vehicle engines emit some nitrous acid that can infiltrate the passenger compartments, tests were also conducted on surfaces inside the truck of a heavy smoker, including the surface of a stainless steel glove compartment. These measurements also showed substantial levels of TSNAs.

Individuals are most likely exposed to these TSNAs through either inhalation of dust or the contact of skin with carpet or clothes, suggesting third-hand smoke might pose the greatest hazard to infants and toddlers.

And the study's findings, detailed in the Feb. 8 issue of the journal Proceedings of the National Academy of Sciences, indicate that opening a window or deploying a fan to ventilate the room while a cigarette burns does not eliminate the hazard of third-hand smoke.

Smoking outdoors is not much of an improvement.

"Smoking outside is better than smoking indoors but nicotine residues will stick to a smoker's skin and clothing," said study co-author Lara Gundel, also of Berkeley Lab. "Those residues follow a smoker back inside and get spread everywhere."

"What we see in this study is that the reactions of residual nicotine with nitrous acid at surface interfaces are a potential cancer hazard, and these results may be just the tip of the iceberg," said Kamlesh Asotra of the University of California's Tobacco-Related Disease Research Program, which funded this study.

In their paper, the authors suggest several ways to limit the impact of third-hand smoke, including the implementation of 100 percent smoke-free environments in public places and self-restrictions in residences and automobiles. In building where high levels of smoking has occurred, replacing furnishings, carpets and wallboard could reduce exposures.

source: msn.com