Category Archives: Food
Don””t Blame Dairy Cows for (Greenhouse) Gas Emissions, New Study Shows
A new study by the University of Arkansas and Michigan Tech shows that the dairy industry — including this Jersey cow — is responsible for only about 2 percent of all US greenhouse gas emissions. (Credit: Photo by Stephen Kennedy, courtesy of the Innovation Center for the US Dairy)
Forget all the tacky jokes about cow flatulence causing climate change. A new study reports that the dairy industry is responsible for only about 2.0 percent of all US greenhouse gas emissions.
The study, led by the University of Arkansas in association with Michigan Technological University, measures the carbon footprint of a gallon of fluid milk from farm to table and uses 2007 and 2008 data from more than 500 dairy farms and 50 dairy processors, as well as data from more than 210,000 round trips transporting milk from farm to processing plant. It was commissioned by the Innovation Center for the US Dairy, an industry-wide group.
The University of Arkansas addressed carbon emissions from the dairy to the milk in your cereal bowl. The Michigan Tech group looked further upstream. “We focused on the carbon footprint of the feed crops,” said chemical engineering professor David Shonnard, director of the Sustainable Futures Institute. “Animal feed is a major contributor to carbon emissions.” Using US Department of Agriculture data, Shonnard””s team, including PhD student Felix Adom and four undergraduates (Ashely Maes, Charles Workman, Zachary Bergmann and Lilian Talla), analyzed the impact of variables ranging from fertilizer and herbicides to harvesting and transportation. “We also looked at a Michigan feed mill, where grain gets combined with any of over a hundred different additives,” he said.
The team concluded that the cumulative total emission of greenhouse gases associated with all fluid milk consumed in the US was approximately 35 million metric tons in 2007. While the emissions are lower than sometimes reported, there is still room for improvement for dairy farms and businesses of all kinds, the study concluded. In particular, manure management, feed production and enteric methane (cow gas) were cited as areas that are ripe for innovation on farms. Energy management provides the greatest opportunity in the processing, transportation and retail segments.
The project has also raised other dairy-related issues that Shonnard””s group is investigating. They are studying the eutrophication of water — what happens when nutrients such as manure and fertilizers get into surface water, causing an overbloom of algae that sucks oxygen from the water and kills fish. The team is also investigating water consumption and land use in the dairy industry. “Growing crops is becoming more productive all the time, and we may be able to use less land to satisfy demand,” Shonnard said.
Story Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Michigan Technological University. The original article was written by Marcia Goodrich.
http://www.sciencedaily.com/releases/2010/10/101018163743.htm
Willy Wonka Gum Could Soon Come to Fruition
Researchers are working on a tasty treat that turns into a three-course-meal.
“We”ll begin, with a spin, traveling in the world of my creation… what we”ll see will defy explanation.”
The lyrics to “Pure Imagination,” a song from the movie Willy Wonka And The Chocolate Factory may be the inspiration for a team of scientists at the Institute of Food Research in Norwich. It is possible that in the very near future, the three course-meal that the character Violet Beauregarde enjoyed in the movie might be made available to everyone.
A medical advancement originally developed to release drugs into the body at different times could soon be offered up as a re-imagined three-course-meal. The researchers are using the technology to create a new type of gum that changes flavor as a person chews it.
Their development allows for different flavors to be held inside microscopic capsules. A special time-release formula means that various flavors can be enjoyed at separate times, with different courses each enclosed in different capsules.
“Tiny nanostructures within the gum would contain each of the different flavors. These would be broken up and released upon contact with saliva or after a certain amount of chewing – providing a sequential taste explosion as you chew harder,” said Professor Dave Hart, a food scientist at the Institute.
Flavor molecules are secured inside of the capsules and encased in an oily shell before they can be absorbed into the food ingredients.
“Wonka”s fantasy concoction has been nothing but a dream for millions of kids across the world. But science and technology is changing the future of food, and these nanoparticles may hold the answer to creating a three course gourmet gum, ” said Hart.
The process was originally pioneered by Professor Tony Dinsmore, from the department of physics at the University of Massachusetts.
http://www.dailytech.com/Willy+Wonka+Gum+Could+Soon+Come+to+Fruition/article19866.htm
New lacquer-based antibacterial active film keeps food fresher, longer
Fraunhofer”s antibacterial food packaging film kills bacteria on food by releasing sorbic acid
By Ben Coxworth
Researchers from Germany’s Fraunhofer Institute for Process Engineering and Packaging have developed a new type of food packaging film that kills food-inhabiting bacteria. While antimicrobial polymers in food packaging have been around for some time, the new material is unique in that it incorporates sorbic acid that has been dissolved into a lacquer, which is then deposited onto the film. When that lacquer first touches the food, a timed release of the acid begins, which neutralizes a significant number of the microorganisms on the food’s surface. The result, according to the researchers, is the ability to keep meat, fish and cheese fresher for longer.
Fraunhofer food chemist Carolin Hauser chose sorbic acid not just because it kills germs, but also because it’s non-toxic, non-allergenic, water-soluble, and doesn’t have a strong smell or taste. It is already used as a preservative in many foods, and is considered environmentally-safe, as it breaks down rapidly in soil.
Hauser used fresh pieces of pork loin for her evaluation of the film. She contaminated each of them with 1,000 colony-forming units of the E. coli bacteria, then wrapped some of them in regular film and some in her product. Differences in color between the two groups were apparent after several days in an 8C (46F) fridge. When she did a microbial analysis, she discovered that the E. coli population on the pork wrapped in her film had decreased to about one quarter its original size.
“After a week, the total germ count on the surface had decreased significantly compared to the meat packed in untreated film,” she said. “This indicates that our active film is suitable for maintaining the freshness – and above all the safety – of meat preparations, cheeses, fish fillets and other cold cuts.”
Researchers discover way to turn off severe allergic reaction to food in mice
A bowl of nuts – delicious for some, potentially deadly for others (Image: Craig Engbrecht)
By Darren Quick
There is no known cure for food allergies with sufferers forced to constantly check the ingredients on food packaging and make enquiries at restaurants before digging into a meal. Even taking such precautions it is almost impossible to avoid all food allergen exposure, especially with children. With even minor exposure having the potential to cause severe or even life threatening reactions in some people, the discovery of a way to turn off the immune system’s allergic reaction to certain proteins in mice, could have implications for the millions of food allergy sufferers worldwide.
Allergic reactions to food occur when the immune system misidentifies an otherwise innocuous food protein as harmful, and then attacks the protein with a ferocity far greater than required. Last year we reported that a team at Duke University discovered it was possible for some people allergic to peanuts to build up a tolerance by slowly giving them higher and higher doses of peanut flour in their food each day. While promising, for this method to remain effective the subjects had to keep a daily dose of peanuts in their diets to maintain the tolerance.
Now a research team at Johns Hopkins University has discovered that one kind of immune cell in the gastrointestinal tract called lamina propria dendritic cells (LPDC), which are considered the first line of defense for a body’s immune system, expresses a special receptor, SIGNR1, which appears on the cells’ surface and binds to specific sugars.
Test results on mice
In the laboratory, the research team, led by Shau-Ku Huang, Ph.D., a professor of medicine, and Yufeng Zhou, M.D., Ph.D., a postdoctoral fellow in the Division of Allergy and Clinical Immunology at Johns Hopkins University School of Medicine, took a food protein that causes allergies in mice and modified it by adding special sugars.
They hypothesized that, when ingested by the mice, the modified proteins would be able to bind to what are known as the SIGNR1 receptors on the immune system cells. Bound in this way, the immune system would learn to tolerate the modified food protein – and the protein would no longer induce an allergic reaction, even when consumed in its unmodified form.
The mice were fed the modified protein once a day for three days. Five days later, they were fed the protein in its unmodified form. Another group of mice was not fed the modified protein at all. The severity of the allergic response to the unmodified protein – which in the control-group mice tended to be tremors, convulsions and/or death – was significantly decreased in those mice that had been pre-fed the modified protein.
Some still had minor reactions like itchiness or puffiness around the eyes and snout, but none had serious ones. These mice appeared to be desensitized to the food protein, even when it was fed to them in its unmodified form, says Zhou. In this model, SIGNR1 plays a key role in shutting off some responses in the immune cells, but the researchers don’t yet know whether this is the only function of this receptor.
Article Continues -> http://www.gizmag.com/switching-off-allergic-reaction-to-food-in-mice/16554/
Peanut Ban On Airplanes? FAA Considers Nut Ban For Airlines Because Of Allergy
By RUSS BYNUM
SAVANNAH, Ga. — Federal regulators are considering a snack attack on the nation’s airlines that would restrict or even completely ban serving peanuts on commercial flights.
Advocates say the move would ease fears and potential harm to an estimated 1.8 million Americans who suffer from peanut allergies. Peanut farmers and food packagers, however, see it as overreaching and unfair to their legume.
“The peanut is such a great snack and such an American snack,” says Martin Kanan, CEO of the King Nut Companies, an Ohio company that packages the peanuts served by most U.S. airlines. “What’s next? Is it banning peanuts in ballparks?”
Twelve years after Congress ordered it to back off peanuts, the U.S. Transportation Department gave notice last week that it’s gathering feedback from allergy sufferers, medical experts, the food industry and the public on whether to ban or restrict in-flight peanuts.
The peanut proposals were listed in an 84-page document including several other proposed consumer protections for air travelers. Three options were given: banning serving of peanuts on all planes; prohibiting peanuts only when an allergic passenger requests it in advance; or requiring an undefined “peanut-free zone” flight when a passenger asks for one.
While those options only pertain to peanuts served by flight crews, the document also states “we are particularly interested in hearing views on how peanuts and peanut products brought on board aircraft by passengers should be handled.”
Spokesman Bill Mosely said the department is responding to concerns from travelers who either suffer from peanut allergies or have allergic children, “some of whom do not fly” because they’re afraid of exposure.
“We’re just asking for comment on whether we should do any of these three things,” Mosely said. “We may not do any of them.”
Peanut allergy can cause life-threatening reactions in people ingesting even trace amounts. Just breathing peanut dust in the air can cause problems – though usually minor ones – such as itching, sneezing and coughing.
Article Continues -> http://www.huffingtonpost.com/2010/06/12/peanut-ban-on-airplaines-_n_610247.html
The Truth About Red Meats and Processed Meats
A study recently published online by the journal Circulation provides some rather meaty data to chew on. Red meat may not increase the risk of heart disease. Processed meat, in contrast, apparently does.
But before the carnivores start licking their chops and stoking their coals, the food for thought served up in this paper requires considerable slicing and dicing. So out with the steak knives, and let’s get to it.
The new study is a meta-analysis examining the effects of red meat and processed meat on heart disease, stroke and diabetes risk. Meta-analyses can be very powerful, but they are intrinsically limited to the quality of the research from which they are pooling data.
In this case, that is an important limitation. Data in the new report are all derived from trials in which consumption of red meat and processed meat were compared. There are relatively few such studies that exclude poultry and fish; the studies in question control variably for other health behaviors that might confound the findings; and most importantly, all of the studies were observational.
That means participants simply reported what they ate, rather than being assigned. While intervention studies are designed to establish cause and effect, observational studies can generally only suggest associations. It may be, for instance, that people who eat beef, but avoid processed meat, are generally more health conscious than those who eat both.
Still, the meta-analysis assessed over a million people. So its findings are worthy of consideration, even if they come encumbered by caveats.
The study suggests that when isolated from processed meat, pure red meat has no meaningful association with heart disease risk. Total meat intake was, the authors state, “associated with a trend toward higher [heart disease] risk.”
Each daily serving of processed meat raised the apparent risk of heart disease by a relative 40 percent. Each serving of total meat per day was linked to a 12 percent rise in the apparent relative risk of diabetes.
Some of the findings came down to statistical subtleties. For example, a 19 percent increase in diabetes risk associated with processed meat intake was significant, whereas a 16 percent increase in such risk with red meat consumption was not. That three percent relative risk difference is decisively trivial. The review lacked statistical power for stroke, but there were positive associations between red meat, processed meat and total meat with stroke risk.
Research findings are more reliable when there are mechanisms to account for them, and in this case, there are. In general, processed meats are higher in saturated fat and lower in protein than pure red meats. More importantly, processed meats are much higher in sodium, and contain compounds such as nitrates and nitrites — both linked to vascular injury and atherosclerosis — in relatively high concentrations.
Of course, red meat does contain saturated fat and cholesterol, which is what makes an apparent lack of association between its intake and heart disease noteworthy. As for saturated fat, it is not all created equal. We have already learned to distinguish saturated fat from unsaturated varieties, and most people know that some sub-categories of fat, such as omega-3, have unique health effects. Our next collective step forward will be to refer to the health effects of specific fatty acids within a given class. About a third of the saturated fat in red meat is stearic acid, which appears to be free of the harmful effects of its classmates.
Dietary cholesterol is very weakly associated with heart disease risk, and may be all but irrelevant. This is unsurprising — cholesterol has been a normal part of the human diet since the Stone Age, when it came from meat and eggs.
Our Stone Age proclivities do not, however, directly support a modern carnivorous bent. Anthropologists suggest that antelope flesh is fairly representative of the meat our ancestors ate. While the flesh of beef cattle is roughly 35 percent fat by calories, most of it saturated, the flesh of antelope is as low as five percent of calories from fat, all of it unsaturated, and some of it omega-3. Not all ungulates are created equal.
The new study cannot distinguish among varieties of red meat. Some is leaner, some is fattier. Just as we are what we eat, so, too, is what we eat. The flesh of grass fed cattle, for example, is more nutritious than that of grain fed cattle.
The study looked at heart disease, stroke and diabetes only. Many studies have linked higher intake of red meat with increased cancer risk, colon cancer risk in particular. This study was blind to that issue.
Also ignored was the fact that eating more meat probably means eating less of other foods. Other foods — namely vegetables, fruits, whole grains, nuts, seeds and fish — have been shown to reduce the risk of heart disease, and of premature death from any cause. What we eat matters both because of what it puts into our mouths, and what it bumps out. A switch to more meat-based eating could very well confer net harm in part because of what it is taking out of your diet.
As pointed out by, among others, T. Colin Campbell in ‘The China Study,’ prevailing protein intake in the U.S. tends to be much in excess of need, and is likely associated with adverse effects on everything from bone density to cancer risk. Eating more meat would compound such concerns.
Raising feed animals comes at a very high environmental cost. As Michael Jacobson and colleagues point out in “Six Arguments for a Greener Diet”, it takes roughly seven lbs of corn to grow one pound of beef; five times as much water to grow feed grains for cattle as to grow fruits and vegetables for ourselves; and roughly ten times the acreage to raise cattle for food as to raise comparable plant food calories for direct human consumption.
Processed meats — sausage, bacon, and the like — are almost certainly harmful in ways that simple, unprocessed red meats are not. But however you choose to digest the news about meat, chew on this: Red meats are, at best, less harmful; there is nothing to suggest they actually promote health. Plant foods do — for people and planet alike.
However you dice the new data, in other words, Michael Pollan’s advice still stands: eat food, not too much … mostly plants!
-fin
Dr. David L. Katz; www.davidkatzmd.com
Follow David Katz, M.D. on Twitter: www.twitter.com/DrDavidKatz
http://www.huffingtonpost.com/david-katz-md/nutrition-advice-the-trut_b_584758.html
Invention Awards: A Box That Keeps Plants Hydrated in the Desert
Thinking Inside the Box Pieter Hoff is testing the Groasis Waterboxx on grapevines at Robert Mondavi’s Napa Valley, California, vineyard. If successful, it could save the winery more than 145,000 gallons of water per acre a year. John B. CarnettA box that quenches thirsty plants without irrigation
By Corey Binns
Dutch flower exporter Pieter Hoff often spent nights in his beloved lily fields to monitor them. One evening, he noticed that the first droplets of morning condensation were collecting on the leaves of his lilies well before midnight.
Invention: Groasis Waterboxx
Inventor: Pieter Hoff
Cost: $7.1 million
Time: 7 years
Is It Ready Yet? 1 2 3 4 5
The plants lost heat to the air at night, and the cool surface of the leaves sucked water droplets from the warm, humid air. Nature’s watering system, Hoff thought, is incredibly efficient. So in 2003, he sold his business and began developing a planter that could capture water the same way plants do and foster saplings in the harshest conditions.
Today, one third of the world’s population lives where water is scarce or of poor quality, a number that’s expected to jump to two thirds by 2025. Making matters worse, in some areas deforestation and overfarming have led to eroded soil that can no longer support many crops. Hoff designed his Groasis Waterboxx with this in mind—it’s a plant incubator that’s made from plastic or a biodegradable material and designed to cool faster than the night air, like his lilies. The box is coolest at its top, the part that has the most contact with the open air. Water condenses on the cover and flows down into a small holding tank, where it’s trapped, along with any rainwater. The collected water and the box itself keep the plant and its roots hydrated and protected.
At the same time, a candle-like wick on the bottom of the box slowly drips small doses of the water into the soil and root system underneath, providing enough for the plant’s first year of life but still leaving the roots thirsty enough to grow strong and deep. The box can easily be lifted up off the ground, over the top of the plant, and reused.
In 2006 Hoff took 25 Waterboxxes to Morocco’s Sahara desert, and after a year, 88 percent of the trees he treated had green leaves, while 90 percent of those watered weekly (the traditional local method) died under the scorching sun. He is conducting more experiments with 20,000 Waterboxxes in difficult terrains in places like Pakistan and Ecuador this year.
Hoff is hoping to recruit people to buy a few Waterboxxes from his Web site (groasis.com) to see how the invention works in other regions he hasn’t reached. “Everywhere you look, there’s space to plant,” he says. “But I can’t do this alone.”
See how the Waterboxx works in detail here.
http://www.popsci.com/diy/article/2010-05/invention-awards-watering-plants-desert
Early Death by Junk Food? High Levels of Phosphate in Sodas and Processed Foods Accelerate the Aging Process in Mice
High levels of phosphates — found in many soft drinks and processed foods — accelerate signs of aging, new research in mice shows. (Credit: iStockphoto/Fuat Kose)
Here’s another reason to kick the soda habit. New research published online in the FASEB Journal shows that high levels of phosphates may add more “pop” to sodas and processed foods than once thought. That’s because researchers have found that the high levels of phosphates accelerate signs of aging. High phosphate levels may also increase the prevalence and severity of age-related complications, such as chronic kidney disease and cardiovascular calcification, and can also induce severe muscle and skin atrophy.
“Humans need a healthy diet and keeping the balance of phosphate in the diet may be important for a healthy life and longevity,” said M. Shawkat Razzaque, M.D., Ph.D., from the Department of Medicine, Infection and Immunity at the Harvard School of Dental Medicine. “Avoid phosphate toxicity and enjoy a healthy life.”
To make this discovery, Razzaque and colleague examined the effects of high phosphate levels in three groups of mice. The first group of mice was missing a gene (klotho), which when absent, causes mice to have toxic levels of phosphate in their bodies. These mice lived 8 to 15 weeks. The second group of mice was missing the klotho gene and a second gene (NaPi2a), which when absent at the same time, substantially lowered the amount of phosphate in their bodies. These mice lived to 20 weeks. The third group of mice was like the second group (missing both the klotho and NaPi2a genes), except they were fed a high-phosphate diet. All of these mice died by 15 weeks, like those in the first group. This suggests that phosphate has toxic effects in mice, and may have a similar effect in other mammals, including humans.
“Soda is the caffeine delivery vehicle of choice for millions of people worldwide, but comes with phosphorous as a passenger” said Gerald Weissmann, M.D., Editor-in-Chief of the FASEB Journal. “This research suggests that our phosphorous balance influences the aging process, so don’t tip it.”
Story Source:
Adapted from materials provided by Federation of American Societies for Experimental Biology, via EurekAlert!, a service of AAAS.
Journal Reference:
- M. Ohnishi, M. S. Razzaque. Dietary and genetic evidence for phosphate toxicity accelerating mammalian aging. The FASEB Journal, 2010; DOI: 10.1096/fj.09-152488
http://www.sciencedaily.com/releases/2010/04/100426151636.htm
Peppers May Increase Energy Expenditure in People Trying to Lose Weight
Hot peppers. (Credit: iStockphoto)
Imagine your delight while enjoying your favorite Mexican food — perhaps a fully loaded bean burrito topped with an ample supply of thinly sliced jalepeño peppers. What happens when you bite into a few more peppers than you bargained for? Does this thought conjure up the thought of a little heat? Perhaps even a bit of sweat on the brow?
Indeed, food scientists can tell you that hot peppers contain a substance called capsaicin that not only adds spice to our foods but can actually cause your body to heat up. They hypothesize that plants evolved to contain capsaicin because it protected them from being eaten by insects and other pesky predators. On the contrary, cuisines worldwide rely on capsaicin-packing peppers to add pungency and zing to many traditional foods, and “pepperheads” often choose their meal to purposefully turn up the heat.
But scientists are learning there is more than meets the eye (or should we say taste buds) when it comes to peppers. In fact, there is growing evidence that the body-heat-generating power of peppers might even lend a hand in our quest to lose those extra inches accumulating around our collective national waistline. And fortunately for those of us who don’t appreciate the “burn” of hot peppers, there are plants that make a non-burning version of capsaicin called dihydrocapsiate (DCT) that could have the benefits of peppers without the pungency.
In a study designed to test the weight-loss potential of this DCT containing, non-spicy cousin of hot peppers, researchers at the UCLA Center for Human Nutrition set out to document its ability to increase heat production in human subjects consuming a weight-loss diet. Under the direction of David Heber (Professor of Medicine and Public Health), they recruited 34 men and women who were willing to consume a very low-calorie liquid meal replacement product for 28 days. The researchers then randomized the subjects to take either placebo pills or supplements containing the non-burning DCT pepper analog. Two dosage levels of DCT were tested. At the beginning and end of the study, body weight and body fat were assessed, and the researchers determined energy expenditure (heat production) in each subject after he or she consumed one serving of the test meal.
On April 27, Heber and his research team presented their results at the Experimental Biology 2010 meeting in Anaheim, CA. This presentation is part of the scientific program of the American Society for Nutrition, home to the world’s leading nutrition researchers.
Their data provided convincing evidence that, at least for several hours after the test meal was consumed, energy expenditure was significantly increased in the group consuming the highest amount of DCT. In fact, it was almost double that of the placebo group. This suggests that eating this pepper-derived substance that doesn’t burn can have the same potential benefit as hot peppers at least in part by increasing food-induced heat production. They were also able to show that DCT significantly increased fat oxidation, pushing the body to use more fat as fuel. This may help people lose weight when they consume a low-calorie diet by increasing metabolism.
Note, however, that a limitation to this study was that the researchers only tested the effect of DCT on the thermic response to a single meal. Heber and colleagues also point out that that there might be a different effect in lean vs. obese subjects. But to their credit, this was the first study ever conducted to examine the potential health benefits of DCT consumed together with a very low calorie diet. The bottom line: don’t be afraid to pile on the peppers.
Dr. David Heber, Dr. Amy Lee, Alona Zerlin, Gail Thames, and Dr. Zhaoping Li are all researchers at UCLA’s Center for Human Nutrition in Los Angeles, CA and were coauthors on this paper.
Story Source:
Adapted from materials provided by Federation of American Societies for Experimental Biology, via EurekAlert!, a service of AAAS.
http://www.sciencedaily.com/releases/2010/04/100427190934.htm
Meat, Especially If It’s Well Done, May Increase Risk of Bladder Cancer
People who eat meat frequently, especially meat that is well done or cooked at high temperatures, may have a higher chance of developing bladder cancer, according to a large study (Credit: iStockphoto/Robert Lerich)
People who eat meat frequently, especially meat that is well done or cooked at high temperatures, may have a higher chance of developing bladder cancer, according to a large study that The University of Texas M. D. Anderson Cancer Center presented at the American Association for Cancer Research 101st Annual Meeting 2010. This risk appears to increase in people with certain genetic variants.
“It’s well known that meat cooked at high temperatures generates heterocyclic amines (HCAs) that can cause cancer,” said study presenter Jie Lin, Ph.D., assistant professor in M. D. Anderson’s Department of Epidemiology. “We wanted to find out if meat consumption increases the risk of developing bladder cancer and how genetic differences may play a part.”
Meat-eating habits examined
According to the American Cancer Society, almost 71,000 new cases of bladder cancer were diagnosed in this country last year, and more than 14,000 people died because of the disease. Men are at much higher risk of developing bladder cancer than women.
HCAs form when muscle meats, such as beef, pork, poultry or fish, are cooked at high temperatures. They are products of interaction between amino acids, which are the foundation of proteins, and the chemical creatine, which is stored in muscles. Past research has identified 17 HCAs that may contribute to cancer.
This study, which took place over 12 years, included 884 M. D. Anderson patients with bladder cancer and 878 people who did not have cancer. They were matched by age, gender and ethnicity.
Using a standardized questionnaire designed by the National Cancer Institute (NCI), researchers gathered information about each participant’s dietary habits. They then categorized people into four levels, ranging from lowest to highest red meat intake.
Well-done red meat nourishes cancer risk
The group with the highest red-meat consumption had almost one-and-a-half times the risk of developing bladder cancer as those who ate little red meat.
Specifically, consumption of beef steaks, pork chops and bacon raised bladder cancer risk significantly. Even chicken and fish — when fried — significantly raised the odds of cancer.
The level of doneness of the meat also had a marked impact. People whose diets included well-done meats were almost twice as likely to develop bladder cancer as those who preferred meats rare.
Further questioning of a subset of 177 people with bladder cancer and 306 people without bladder cancer showed that people with the highest estimated intake of three specific HCAs were more than two-and-a-half times more likely to develop bladder cancer than those with low estimated HCA intake.
“To quantify intakes of HCAs, we began three or four years ago to gather information on meat-cooking methods and doneness level, and then used a program developed by the NCI to estimate intakes of three major HCAs,” Lin said. “These data gave important information about the relationship between HCAs and bladder cancer.”
Genetic variants increase incidence
To take the investigation a step further, researchers analyzed each participant’s DNA to find if it contained genetic variants in the HCA metabolism pathways that may interact with red meat intake to increase the risk of cancer.
People with seven or more unfavorable genotypes as well as high red-meat intake were at almost five times the risk of bladder cancer.
“This research reinforces the relationship between diet and cancer,” said Xifeng Wu, M.D., Ph.D., professor in M. D. Anderson’s Department of Epidemiology and lead author on the study. “These results strongly support what we suspected: people, who eat a lot of red meat, particularly well-done red meat, such as fried or barbecued, seem to have a higher likelihood of bladder cancer. This effect is compounded if they carry high unfavorable genotypes in the HCA-metabolism pathway.”
Wu said this research is a step toward a future in which a comprehensive cancer-risk prediction model will integrate environmental, diet and genetic risk factors to predict an individual’s chances of developing cancer.
Co-authors with Lin and Wu included Jian-Ming Wang, M.D., Ph.D., and Meng Chen, Ph.D., also of M. D. Anderson’s Department of Epidemiology, and H. Barton Grossman, M.D., and Colin P. Dinney, M.D., of the Department of Urology.
This research is supported by funding from National Cancer Institute.
Story Source:
Adapted from materials provided by University of Texas M. D. Anderson Cancer Center.
http://www.sciencedaily.com/releases/2010/04/100419150827.htm
