Thursday, May 29, 2008

Moderate wine drinking promotes a healthier liver

Or does it? Maybe it does but the study below does not prove it. The study is better than many in that it did control for social class variables but there are many things not controlled for -- such as personality, diet and lifestyle. Are we to assume that non-drinkers and moderate drinkers are the same on average? Surely not. Yet we would have to assume that to make the causal inferences below.

Amusing that wine is found to be good for you but beer is bad. All of the results below were quite predictable from the probable habits of the researchers. Wine has been getting a good rap for some years now. Anybody would think that wine-drinking had become popular among the bourgeoisie in recent years! Oh dear!

I am sure that the researchers would be quite huffy about the suggestion I have just made but they should read up on the Rosenthal effect

Popular summary below followed by journal abstract

In Hepatology this week, researchers have shown that moderate wine consumption decreases the risk of developing fatty liver disease. A total of 11,754 adults aged 21 and over were involved in the study -- 7211 non-drinkers and 4543 moderate drinkers. "Moderate" was defined as having up to an average of one drink per day of either 120 millilitres (ml) of wine, 350ml of beer or 30ml of spirits. Compared to non-drinkers, those who drank one glass of wine a day had half the risk of developing fatty liver disease. But those who drank moderate amounts of beer or spirits had more than four times the risk of liver disease as non-drinkers.


Modest wine drinking and decreased prevalence of suspected nonalcoholic fatty liver disease

By Winston Dunn et al.


People at risk for coronary heart disease are often at risk for nonalcoholic fatty liver disease (NAFLD). The association of modest wine consumption with NAFLD has not been studied and the recommendation of wine for patients at risk for both diseases is controversial. The aim is to test the hypothesis that modest wine consumption is associated with decreased prevalence of NAFLD. We included Third National Health and Nutrition Examination Survey participants who either reported no alcohol consumption or preferentially drinking wine with total alcohol consumption up to 10 g per day. Suspected NAFLD was based on unexplained serum alanine aminotransferase (ALT) elevation over the cut point of the reference laboratory (ALT > 43) and the cut point based on the 95th percentile of healthy subjects (ALT > 30 for men; ALT > 19 for women).

Multivariate analysis was adjusted for age, gender, race, neighborhood, income, education, caffeine intake, and physical activity. A total of 7,211 nondrinkers and 945 modest wine drinkers comprised the study sample. Based on the reference laboratory cut point, suspected NAFLD was observed in 3.2% of nondrinkers and 0.4% of modest wine drinkers. The adjusted odds ratio was 0.15 (95% confidence interval, 0.05-0.49). Using the healthy subject cut point, suspected NAFLD was observed in 14.3% of nondrinkers and 8.6% of wine drinkers. The adjusted odds ratio was 0.51 (95% confidence interval, 0.33-0.79). Conclusion: Modest wine consumption is associated with reduced prevalence of suspected NAFLD. The current study supports the safety of one glass of wine per day for cardioprotection in patients at risk for both coronary heart disease and NAFLD.

HEPATOLOGY 2008, Volume 47, Issue 6 , Pages 1947 - 1954

What happened to the obesity "epidemic"?

The percentage of children who are obese has been roughly stable since 1999, but no one knows why. But why not?

The stunning three-decade rise in childhood obesity that prompted the government to declare an "epidemic" of fat appears to have leveled off, although the rate is still more than three times higher than in the 1970s, researchers reported today. The analysis was based on data from tens of thousands of children showing that the percentage of obese youngsters has been roughly stable since 1999 in every age and racial group they surveyed.

The level of obesity "is still too high," said lead author Cynthia Ogden, an epidemiologist with the federal Centers for Disease Control and Prevention. But she added: "Maybe there is some cause for optimism."

The mystery is what caused the plateau. The leading possibility is that educational and regulatory campaigns to get children to eat less junk food and exercise more have begun to pay off.

The findings "may signal that this national epidemic is not an unstoppable force," said Dr. Risa Lavizzo-Mourey, president of the Robert Wood Johnson Foundation, which has committed $500 million to promoting physical activity in communities and improving nutrition in schools. "When parents, government, schools, the food and beverage industries, other businesses, and the nonprofit and philanthropic sectors work together, we can make progress, and we can reverse this epidemic," she said in a statement.

Some researchers, however, said the answer could be that the epidemic has simply reached a saturation point -- kids just can't get any fatter. "Eventually it had to level off," said S. Jay Olshansky, an epidemiologist at the University of Illinois at Chicago who was not involved in the study. "The question was when. Maybe this is it."

The rise in obesity among children and adults has been one of the biggest public health issues of the last few years, both in this country and around the world. It was first noticed by researchers in the 1980s as a relentless upward slope that threatened to undo progress on heart disease and exacerbate other killer illnesses influenced by weight, including diabetes, high blood pressure and some types of cancer.

The CDC issued an unsettling report in 2004 [later discredited] that concluded obesity caused 400,000 deaths a year in the United States, just slightly below the death toll from smoking. About a third of U.S. adults are obese, based on a measurement known as body mass index, a ratio of height and weight.

Of particular concern has been obesity in children because their eating patterns set them on course for lifelong health problems. One study in 2005 found that as a result of obesity, children today could be the first generation of the modern era to live shorter lives than their parents.

The latest study, published in the Journal of the American Medical Assn., showed that 16.3% of children ages 2 to 19 are obese and an additional 15.6% are overweight.

The government has been tracking the heights and weights of children since the 1970s as part of an ongoing health and nutrition survey. By today's definition, 5% of children at that time were obese and 10% were overweight.

The latest analysis, which looked at 4,207 children surveyed in 2005 and 2006, found their BMIs did not differ significantly from children surveyed in 2003 and 2004.

When the researchers incorporated the new numbers into their analysis, their statistical model showed that 1999 marked the beginning of the leveling off. The finding tracks with a study last year showing a stabilization of obesity rates among adults.

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