Sunday, November 18, 2007


We must stop the peasants from drinking! Popular summary below followed by Abstract. This is in most ways an unusually high-quality study. They actually made an attempt at community sampling and controlled for a few obvious things! Wow! Most unusual in the medical literature. But the heading on the journal article rightly shows an awareness that the causal inferences are still a problem.

The findings about attention deficit disorders are particularly interesting. What looks at first like an alcohol effect was shown on closer examination to be a family effect. Conduct problems generally, however, could not be ruled out as a family effect. This fits in with a view that attention-deficit syndrome is more strongly genetically determined than are conduct problems generally.

A major weakness of the study, however, is its reliance on maternal reports. This makes it particularly important that there was a failure to control for many possibly relevant psychological variables in the mother. To expect that there are not important psychological differences between mothers who drink daily and mothers who do not drink at all would be naive in the extreme -- yet it seems primarily to be the difference between the children of those groups of mothers upon which the researchers hang their hat.

It could be asserted, for instance, that neurotic (or depressed, or introverted or abused or ....) mothers were both heavier drinkers and more likely to report problem behaviour in their children. In that case, the alcohol would NOT be the causal variable in the observed correlation. Only a study that used direct observation of behaviour could rule out such possibilities -- though use of a comprehensive personality inventory would go some way towards alleviating doubts.

It may be worth noting that the conclusions below do not necessarily conflict with the recent study that found binge drinking to be harmless -- as the study below focuses on chronic alcohol use. The contrast with the findings of the binge-drinking findings does however suggest that the generalizations permitted by the study below may be too crude to be useful. The question clearly now is HOW MUCH and WHEN drinking is harmful and the study below lacks the detail that would enable an answer to that

In the Archives of General Psychiatry this week, researchers report that women who drink alcohol during pregnancy increase the chances of their children having conduct problems. The study involved 4912 mothers and 8621 of their children. Mothers were surveyed about their substance use during each of their pregnancies, with average intakes ranging from zero to six standard drinks per day. Children were assessed every second year between ages 4 and 11 for behavioural problems.

For each additional day per week that mothers drank alcohol during pregnancy, their children showed a significant increase in conduct problems. And the findings held true even after accounting for other factors, including the mothers' drug use during pregnancy, education level and intellectual ability.


Causal Inferences Regarding Prenatal Alcohol Exposure and Childhood Externalizing Problems

By Brian M. D'Onofrio et al.

Context: Existing research on the neurobehavioral consequences of prenatal alcohol exposure (PAE) has not adequately accounted for genetic and environmental confounds.

Objective: To examine the association between PAE and offspring externalizing problems in a large representative sample of families in the United States using measured covariates and a quasi-experimental design to account for unmeasured genetic and environmental confounds.

Design: This study combines information from the National Longitudinal Survey of Youth and the Children of the National Longitudinal Survey of Youth. The analyses statistically controlled for measured characteristics of the mothers and families and exposure to other prenatal psychoactive substances. In the primary analyses, siblings differentially exposed to prenatal alcohol were compared.

Setting and Participants: Women were recruited from the community using a stratified and clustered probability sample and were followed longitudinally. The sample included 8621 offspring of 4912 mothers.

Main Outcome Measures: Maternal report of conduct problems (CPs) and attention/impulsivity problems (AIPs) during childhood (ages 4-11 years) using standardized assessments related to psychiatric diagnoses.

Results: There was an association between PAE and offspring CPs that was independent of confounded genetic and fixed environmental effects and the measured covariates. The CPs in children of mothers who drank daily during pregnancy were 0.35 SD greater than those in children whose mothers never drank during pregnancy. Although AIPs were associated with PAE when comparing unrelated offspring, children whose mothers drank more frequently during pregnancy did not have more AIPs than siblings who were less exposed to alcohol in utero. Additional subsample analyses suggested that maternal polysubstance use during pregnancy may account for the associations between PAE and AIPs.

Conclusion: These results are consistent with PAE exerting an environmentally mediated causal effect on childhood CPs, but the relation between PAE and AIPs is more likely to be caused by other factors correlated with maternal drinking during pregnancy.

Arch Gen Psychiatry. 2007;64(11):1296-1304

A bit more support for the expected influence of caloric restriction in humans

Eating little may help people live longer, a study has found, offering support for an idea that has tantalized scientists for decades.

Researchers have long known that cutting animals' food supply to nearstarvation levels gives themfor reasons still unclearlonger lives and healthier old age. Studies have found that in humans, too, sharply reduced eating is associated with healthier aging, as long as nutritional balance is maintained.

But whether this practice could actually lengthen our lives has remained uncertain.

Some scientists have argued that it's doubtful, because humans already live unusually long. Only one small past study in humans offered weak evidence that people eating less lived longer, according to its authors, who were also involved in the new research.

The new study is the first to probe the claim by comparing human populations, wrote the American and Japanese scientists in a report on their findings.

Moreover, they added, it's "the first study that has shown extended average and maximum life span in a human population that is potentially due to" reduced eating. The practice is known as caloric restriction.

The researchers studied residents of the Japanese island of Okinawa, known through much of the last century both for exceptionally longlived inhabitants and for very spare, though balanced diets. The investigators said they found evidence that the two things are at least partially related.

Although that conclusion might seem obvious to somegiven the past researchthe scientists wrote that to reach it, they had to account for some factors that had hampered systematic analysis. For one, Okinawan diets have changed, becoming richer since about the end of the 1960s. Also, it wasn't clear how to best assess historical dietary intake and compare it to that of other populations.

The findings, by Bradley Willcox of the Pacific Health Research Institute and John A. Burns School of Medicine in Honolulu and colleagues, appear in the November issue of the research journal Annals of the New York Academy of Sciences.

Animal tests have found that the extreme dieting of caloric restriction entails cutting some 40 percent of calories to get the strongest lifeextending effects. Animals placed on such regimens live up to 40 percent longer than normal, as long as the diet remains nutritionally balanced. (Some scientists proposeagain based mostly on animal teststhat taking a substance called resveratrol may replicate caloric restriction's benefits, without the unpleasantness.)

Willcox and colleagues found that at least from the mid20th century through the 1960s, the Okinawan diet was about 11 percent short of what would normally be recommended to maintain body weight. As of 1995, the average Okinawan lived about five years longer than the average American, and about 18 months more than the average Japanese.

The islanders' spartan diets may have been a legacy of "periodic crop failures that occurred in Okinawa in the early 20th century and a long history of marginal food supply," the researchers wrote.

The study had some weaknesses, they added; for instance, it couldn't rule out that Okinawans lived longer because of the types of nutrients they ate, rather than the amount. Nonetheless, the "tentative" findings fit with a broad array of animal studies, and point to a need for still more research, Willcox and colleagues wrote.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

9). And how odd it is that we never hear of the huge American study which showed that women who eat lots of veggies have an INCREASED risk of stomach cancer? So the official recommendation to eat five lots of veggies every day might just be creating lots of cancer for the future! It's as plausible (i.e. not very) as all the other dietary "wisdom" we read about fat etc.

10). And will "this generation of Western children be the first in history to lead shorter lives than their parents did"? This is another anti-fat scare that emanates from a much-cited editorial in a prominent medical journal that said so. Yet this editorial offered no statistical basis for its opinion -- an opinion that flies directly in the face of the available evidence.

Even statistical correlations far stronger than anything found in medical research may disappear if more data is used. A remarkable example from Sociology:
"The modern literature on hate crimes began with a remarkable 1933 book by Arthur Raper titled The Tragedy of Lynching. Raper assembled data on the number of lynchings each year in the South and on the price of an acre's yield of cotton. He calculated the correla-tion coefficient between the two series at -0.532. In other words, when the economy was doing well, the number of lynchings was lower.... In 2001, Donald Green, Laurence McFalls, and Jennifer Smith published a paper that demolished the alleged connection between economic condi-tions and lynchings in Raper's data. Raper had the misfortune of stopping his anal-ysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic condi-tions deteriorated, yet lynchings continued to fall. The correlation disappeared altogether when more years of data were added."
So we must be sure to base our conclusions on ALL the data. But in medical research, data selectivity and the "overlooking" of discordant research findings is epidemic.


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