Thursday, April 03, 2008

Apathy and Global warming

Increased knowledge about global warming leads to apathy, study shows

The more you know the less you care - at least that seems to be the case with global warming. A telephone survey of 1,093 Americans by two Texas A&M University political scientists and a former colleague indicates that trend, as explained in their recent article in the peer-reviewed journal Risk Analysis.

"More informed respondents both feel less personally responsible for global warming, and also show less concern for global warming," states the article, titled "Personal Efficacy, the Information Environment, and Attitudes toward Global Warming and Climate Change in the USA."

The study showed high levels of confidence in scientists among Americans led to a decreased sense of responsibility for global warming.

The diminished concern and sense of responsibility flies in the face of awareness campaigns about climate change, such as in the movies An Inconvenient Truth and Ice Age: The Meltdown and in the mainstream media's escalating emphasis on the trend.

The research was conducted by Paul M. Kellstedt, a political science associate professor at Texas A&M; Arnold Vedlitz, Bob Bullock Chair in Government and Public Policy at Texas A&M's George Bush School of Government and Public Service; and Sammy Zahran, formerly of Texas A&M and now an assistant professor of sociology at Colorado State University.

Kellstedt says the findings were a bit unexpected. The focus of the study, he says, was not to measure how informed or how uninformed Americans are about global warming, but to understand why some individuals who are more or less informed about it showed more or less concern.

"In that sense, we didn't really have expectations about how aware or unaware people were of global warming," he says.

But, he adds, "The findings that the more informed respondents were less concerned about global warming, and that they felt less personally responsible for it, did surprise us. We expected just the opposite.

"The findings, while rather modest in magnitude - there are other variables we measured which had much larger effects on concern for global warming - were statistically quite robust, which is to say that they continued to appear regardless of how we modeled the data."

Measuring knowledge about global warming is a tricky business, Kellstedt adds.

"That's true of many other things we would like to measure in surveys, of course, especially things that might embarrass people (like ignorance) or that they might feel social pressure to avoid revealing (like prejudice)," he says.

"There are no industry standards, so to speak, for measuring knowledge about global warming. We opted for this straightforward measure and realize that other measures might produce different results."

Now, for better or worse, scientists have to deal with the public's abundant confidence in them. "But it cannot be comforting to the researchers in the scientific community that the more trust people have in them as scientists, the less concerned they are about their findings," the researchers conclude in their study.

Texas A&M University, March 28, 2008

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Wednesday, March 12, 2008

Smoking habits of 912 college students

Smoking Habits of College Freshmen

Studies show that smoking initiation typically occurs at age 15 or 16 and over a two- or three-year period gradually increases to daily smoking. Daily smokers continue to escalate their use of cigarettes over the next several years as they develop into chronic, heavily dependent smokers.

This study looked at the daily smoking habits of 912 college students at Purdue University during their freshman year to understand some of the factors that influence trajectories of smoking behavior and tobacco dependence. Students were assessed weekly over the course of the academic year using a web-based survey and provided monthly saliva samples for cotinine analysis. Rates of alcohol and marijuana use were also examined.

Results revealed several patterns of substance use. Heightened use of cigarettes, alcohol, and marijuana were observed during the earliest weeks of school, followed by steady rates of decline over the next several weeks, suggesting that many college freshmen initially experiment with substance use upon arriving on campus, but do not continue to use. Results also found a weekly pattern of smoking, with most cigarettes smoked on Fridays and Saturdays. This pattern was relative consistent across the academic year, with the exception of specific holidays when rates of use increased (i.e., Halloween and New Years Eve), and specific weeks when rates of use decreased (i.e., finals week, winter and spring break). Patterns of smoking and alcohol use were similar, especially for students with higher levels of use.

Among freshmen who had smoked very little prior to beginning college, findings revealed that their initial early-use episodes of smoking during college occurred within a social/party setting and that over 90% occurred when the person was with other people who were smoking. In addition, the majority (65%) of the first recorded early use of cigarettes occurred while the participant was drinking alcohol.


Title of Paper: "Smoking in College Freshmen: University Project of the Tobacco Etiology Research Network (UpTERN)." Lead author: Stephen T. Tiffany, University of Utah.

Health Matrix, Inc., December 04, 2007
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Monday, February 25, 2008

Potentially help for clinicians treat marijuana addiction

Marijuana withdrawal as bad as withdrawal from cigarettes
 
Study could potentially help clinicians treat marijuana addiction

Research by a group of scientists studying the effects of heavy marijuana use suggests that withdrawal from the use of marijuana is similar to what is experienced by people when they quit smoking cigarettes. Abstinence from each of these drugs appears to cause several common symptoms, such as irritability, anger and trouble sleeping - based on self reporting in a recent study of 12 heavy users of both marijuana and cigarettes.

"These results indicate that some marijuana users experience withdrawal effects when they try to quit, and that these effects should be considered by clinicians treating people with problems related to heavy marijuana use," says lead investigator in the study, Ryan Vandrey, Ph.D., of the Department of Psychiatry at the Johns Hopkins University School of Medicine.

Marijuana is the most widely used illicit drug in the United States. Admissions in substance abuse treatment facilities in which marijuana was the primary problem substance have more than doubled since the early 1990s and now rank similar to cocaine and heroin with respect to total number of yearly treatment episodes in the United States, says Vandrey.

He points out that a lack of data, until recently, has led to cannabis withdrawal symptoms not being characterized or included in medical reference literature such as the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, (DSM-IV) or the International Classification of Diseases, 10th edition (ICD-10).

Since the drafting of the DSM-IV in 1994, an increasing number of studies have surfaced suggesting that cannabis has significant withdrawal symptoms. What makes Vandrey's recent study unique is that it is the first study that compares marijuana withdrawal symptoms to withdrawal symptoms that are clinically recognized by the medical community - specifically the tobacco withdrawal syndrome.

"Since tobacco withdrawal symptoms are well documented and included in the DSM-IV and the IDC-10, we can infer from the results of this comparison that marijuana withdrawal is also clinically significant and should be included in these reference materials and considered as a target for improving treatment outcomes," says Vandrey.

Vandrey added that this is the first "controlled" comparison of the two withdrawal syndromes in that data was obtained using rigorous scientific methods - abstinence from drugs was confirmed objectively, procedures were identical during each abstinence period, and abstinence periods occurred in a random order. That tobacco and marijuana withdrawal symptoms were reported by the same participants, thus eliminating the likelihood that results reflect physiological differences between subjects, is also a strength of the study.

Interestingly, the study also revealed that half of the participants found it easier to abstain from both substances than it was to stop marijuana or tobacco individually, whereas the remaining half had the opposite response.

"Given the general consensus among clinicians that it is harder to quit more than one substance at the same time, these results suggest the need for more research on treatment planning for people who concurrently use more than one drug on a regular basis," says Vandrey.

Vandrey's study, which appears in the January issue of the journal Drug and Alcohol Dependence, followed six men and six women at the University of Vermont in Burlington and Wake Forest University School of Medicine in Winston-Salem, N.C., for a total of six weeks. All were over 18 (median age 28.2 years), used marijuana at least 25 days a month and smoked at least 10 cigarettes a day. None of the subjects intended to quit using either substance, did not use any other illicit drugs in the prior month, were not on any psychotropic medication, did not have a psychiatric disorder, and if female, were not pregnant.

For the first week, participants maintained their normal use of cigarettes and marijuana. For the remaining five weeks, they were randomly chosen to refrain from using either cigarettes, marijuana or both substances for five-day periods separated by nine-day periods of normal use. In order to confirm abstinence, patients were given daily quantitative urine toxicology tests of tobacco and marijuana metabolites.

Withdrawal symptoms were self reported on a daily basis Monday through Friday using a withdrawal symptom checklist that listed scores for aggression, anger, appetite change, depressed mood, irritability, anxiety/nervousness, restlessness, sleep difficulty, strange dreams and other, less common withdrawal symptoms. Patients also provided an overall score for discomfort they experienced during each abstinence period.

Results showed that overall withdrawal severity associated with marijuana alone and tobacco alone was of similar frequency and intensity. Sleep disturbance seemed to be more pronounced during marijuana abstinence, while some of the general mood effects (anxiety, anger) seemed to be greater during tobacco abstinence. In addition, six of the participants reported that quitting both marijuana and tobacco at the same time was more difficult than quitting either drug alone, whereas the remaining six found that it was easier to quit marijuana or cigarettes individually than it was to abstain from the two substances simultaneously.

Vandrey recognizes that the small sample size is a limitation in this study, but the results are consistent with other studies indicating that marijuana withdrawal effects are clinically important.


Johns Hopkins Medical Institutions, January 25, 2008
http://www.brightsurf.com/news/headlines/35548/Marijuana_withdrawal_as_bad_as_withdrawal_from_cigarettes.html

Saturday, February 16, 2008

Diet in the origin of metabolic syndrome


Dietary Intake and the Development of the Metabolic Syndrome

The Atherosclerosis Risk in Communities Study

Pamela L. Lutsey, MPH; Lyn M. Steffen, PhD, MPH, RD; June Stevens, PhD, MS, RD
From the Division of Epidemiology and Community Health, University of Minnesota, School of Public Health, Minneapolis (P.L.L., L.M.S.), and Department of Nutrition, University of North Carolina, Chapel Hill (J.S.).


Background— The role of diet in the origin of metabolic syndrome (MetSyn) is not well understood; thus, we sought to evaluate the relationship between incident MetSyn and dietary intake using prospective data from 9514 participants (age, 45 to 64 years) enrolled in the Atherosclerosis Risk in Communities (ARIC) study.

Methods and Results— Dietary intake was assessed at baseline via a 66-item food frequency questionnaire. We used principal-components analysis to derive "Western" and "prudent" dietary patterns from 32 food groups and evaluated 10 food groups used in previous studies of the ARIC cohort. MetSyn was defined by American Heart Association guidelines. Proportional-hazards regression was used. Over 9 years of follow-up, 3782 incident cases of MetSyn were identified. After adjustment for demographic factors, smoking, physical activity, and energy intake, consumption of a Western dietary pattern (Ptrend=0.03) was adversely associated with incident MetSyn. After further adjustment for intake of meat, dairy, fruits and vegetables, refined grains, and whole grains, analysis of individual food groups revealed that meat (Ptrend<0.001), fried foods (Ptrend=0.02), and diet soda (Ptrend=< 0.001) also were adversely associated with incident MetSyn, whereas dairy consumption (Ptrend=0.006) was beneficial. No associations were observed between incident MetSyn and a prudent dietary pattern or intakes of whole grains, refined grains, fruits and vegetables, nuts, coffee, or sweetened beverages.

Conclusions— These prospective findings suggest that consumption of a Western dietary pattern, meat, and fried foods promotes the incidence of MetSyn, whereas dairy consumption provides some protection. The diet soda association was not hypothesized and deserves further study.

Circulation. 2008;117:754-761.
© 2008 American Heart Association, Inc.

Wednesday, February 06, 2008

New dietary guidelines based on fructose

Too much fructose could leave dieters sugar shocked

In fact, many dieters may actually be cutting out the wrong foods altogether, according to findings from a UF paper published recently in the European Journal of Nutrition. Dieters should focus on limiting the amount of fructose they eat instead of cutting out starchy foods such as bread, rice and potatoes, report the researchers, who propose using new dietary guidelines based on fructose to gauge how healthy foods are.

"There's a fair amount of evidence that starch-based foods don't cause weight gain like sugar-based foods and don't cause the metabolic syndrome like sugar-based foods," said Dr. Richard Johnson, the senior author of the report, which reviewed several recent studies on fructose and obesity. "Potatoes, pasta, rice may be relatively safe compared to table sugar. A fructose index may be a better way to assess the risk of carbohydrates related to obesity."

Many diets -- including the low-carb variety -- are based on the glycemic index, which measures how foods affect blood glucose levels. Because starches convert to glucose in the body, these diets tend to limit foods such as rice and potatoes.

While table sugar is composed of both glucose and fructose, fructose seems to be the more dangerous part of the equation, UF researchers say. Eating too much fructose causes uric acid levels to spike, which can block the ability of insulin to regulate how body cells use and store sugar and other nutrients for energy, leading to obesity, metabolic syndrome and type 2 diabetes, said Johnson, the division chief of nephrology and the J. Robert Cade professor of nephrology in the UF College of Medicine. UF researchers first detailed the role of uric acid on insulin resistance and obesity in a 2005 study in rats.

"Certainly we don't think fructose is the only cause of the obesity epidemic," Johnson said. "Too many calories, too much junk food and too much high-fat food are also part of the problem. But we think that fructose may have the unique ability to induce insulin resistance and features of the metabolic syndrome that other foods don't do so easily."

About 33 percent of adults in the United States are overweight or obese, according to the Centers for Disease Control and Prevention.

Studies at other institutions have shown that following a low-glycemic diet can reduce the risk for diabetes and heart disease, but the effect could occur because these dieters often are unintentionally limiting fructose as well by cutting out table sugar, Johnson said.

"Processed foods have a lot of sugar," Johnson said. "Probably the biggest source (of fructose) is soft drinks."

Johnson also noted that, in relation to obesity, the type of fructose found in foods doesn't seem to matter. For example, the fructose in an apple is as problematic as the high-fructose corn syrup in soda. The apple is much more nutritious and contains far less sugar, but eating multiple apples in one sitting could send the body over the fructose edge.

In another UF paper, published in October in the American Journal of Clinical Nutrition, Johnson and his collaborators tracked the rise of obesity and diseases such as diabetes with the rise in sugar consumption. The rates of hypertension, diabetes and childhood obesity have risen steadily over the years.

"One of the things we have learned is this whole epidemic brought on by Western diet and culture tracks back to the 1800s," he said. "Nowadays, fructose and high-fructose corn syrup are in everything."

Aside from soft drinks, fructose can be found in pastries, ketchup, fruits, table sugar and jellies and in many processed foods, including the sugar substitute high fructose corn syrup.

UF researchers plan to test a low-fructose diet in patients soon, Johnson said.

Kathleen Melanson, an associate professor of nutrition and food sciences at the University of Rhode Island, said establishing a fructose index for foods could "be an appropriate approach," depending on how foods are classified. It makes sense to limit foods prepared with high fructose corn syrup and table sugar, which often contain empty calories, but fruits are an important part of a person's diet, she added.

"One concern I have always had with the glycemic index is the potential to pigeonhole foods as good or bad," she said. (December 13, 2007)


University of Florida
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