Tuesday, March 25, 2008

Damage to unborn baby from smoking 'negligible' in the first five months

This is a nice bit of iconoclasm. Rather in line with the passive smoking findings, too. The authors even managed to reject the "correlation is causation" belief that seems to pervade medical research. Will wonders never cease?

Smoking in pregnancy is far less damaging to the unborn baby than commonly supposed, detailed analysis suggests. If women give up smoking by the fifth month of pregnancy, the effect on the baby is negligible, the study found. And even if they do not, the effect on birthweight is surprisingly small. The study by Emma Tominey, a research assistant at the Centre for Economic Performance at the London School of Economics, throws new light on government efforts to stop women smoking when they become pregnant. While it does not suggest that such efforts are pointless, it shows that directing advice towards the newly pregnant is worthwhile.

It also shows that the worst effects are suffered by women from the poorest backgrounds, because in their case smoking is often combined with other unhealthy activities, such as poor diet and consumption of alcohol. Middle-class women suffer almost no damaging effects, the analysis suggests, even if they continue to smoke throughout pregnancy.

The findings, published as a report by the centre, will not be welcomed by anti-smoking groups, whose message to young women is intended to make them feel guilty about damaging their babies. In Ms Tominey's view, the damage is real but relatively small, and even if all women gave up smoking, only about one in eight babies with a low birthweight would avoid being classified as such.

The report uses data from the UK National Child Development Study, which provides details of mothers and their children between 1973 and 2000 - a total of 3,368 women and 6,860 children. The information includes the mothers' smoking habits, information about their families, and the birthweight and gestation period of the children.

Analysis of the data shows that smoking throughout pregnancy reduces birthweight by 5.6 per cent, and the gestation period by just over a day. But when the results are corrected for other factors, such as diet, lifestyle and alcohol, the effect of smoking on birthweight drops to 1.8 per cent and the reduction in gestation becomes insignificant. The study also finds that, contrary to the normal belief that damage is done early in pregnancy, it is the final third that matters most, because this is when babies gain the most weight.

Another surprising finding is the strong class effect. The damage is greatest among mothers with the lowest levels of education. Those who leave school at 16 cause twice the harm to their babies with each cigarette smoked. Ms Tominey concludes: "Other behaviours of the mother play a large role . . . over and above her smoking habits." Policies intended to help babies should aim to educate mothers generally, not simply try to persuade them to stop smoking, she said.

However, she does not conclude that smoking is harmless. "We find that up to 13 per cent of children classified as low-birthweight born to smoking mothers could have been classified as healthy, had their mothers not smoked." The policy implications, however, are that stopping smoking alone is not enough to deal with inequalities in child health, she concludes. "Not only is it the low-socioeconomic-status mothers who choose to smoke, but they are also the mothers bearing the greatest burden from the smoking." She said: "Therefore, any potential solution must offer help to these mothers, to target those with the worst habits and poorest records of child health."


Wow! Big risk from "old" blood

This rather amplifies my comments about transfusions in the side-column. People are finally doing research into transfusions -- and entrenched assumptions are falling like ninepins

Thousands of heart surgery patients may be at risk from transfusions of blood that has been stored for two weeks or more. A study of more than 9,000 patients in the US has shown that those given blood more than 14 days old are 65 per cent more likely to die before discharge, and 50 per cent more likely to die within a year. Recipients of older blood are also at much higher risk of blood poisoning and multi-organ failure, according to the survey at the Cleveland Clinic in Ohio.

Blood is usually more than ten days old before it even reaches British hospitals, so patients here are at least as likely as those in America to receive blood that is more than two weeks old. As there are at least 30,000 cardiac operations a year in Britain, half involving blood transfusions, many patients could be at risk. Professor Peter Weissberg, the medical director of the British Heart Foundation, said that the safety of blood transfusions given to heart surgery patients should urgently be reviewed. "This research suggests that the longer transfused blood has been stored, the greater the risk of complications following cardiac surgery. Further research is urgently needed to clarify the indications for transfusion and the effects of blood storage on outcome," he said.

He said that research carried out for his foundation in Bristol last year indicated that many transfusions given to heart patients did more harm than good. "Together, these studies suggest that only those whose lives are at serious risk without a transfusion should receive blood," he said.

The Cleveland Clinic researchers, writing in The New England Journal of Medicine, say that changes are needed urgently to prevent unnecessary deaths among this large but vulnerable group of patients. According to Colleen Koch, the lead researcher, the results suggest "that blood should be classified as outdated earlier than current recommendations". On the basis of earlier laboratory studies, Dr Koch speculates that by the age of two weeks the structure of stored red blood cells has begun to break down. This, she says, may increase the risk that they will block blood vessels and reduce their capacity to carry oxygen.

Her team studied the records of patients who had major heart surgery at the hospital between June 1998 and January 2006. A total of 2,872 patients received blood that had been stored for 14 days or less, and 3,130 patients received blood that was more than 14 days old. The mean storage age was 11 days for the newer blood and 20 days for the older blood.

The number dying in hospital was significantly higher among those who were given older blood: 2.8 per cent compared with 1.7 per cent, while death rates a year on, at 11 per cent, were nearly half as high again as those who were given newer blood (7.4 per cent). There was no significant difference in the amount of blood received by the patients in the two groups.

Gavin Murphy, a senior lecturer in cardiac surgery at the University of Bristol who led last year's British Heart Foundation study, said that the routine use of transfusions for heart surgery patients put them in danger and was a huge drain on resources. Giving transfusions and treating transfusion-related illnesses increased the overall cost of staying in hospital by more than 40 per cent.



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 correlation 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 conditions and lynchings in Raper's data. Raper had the misfortune of stopping his analysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic conditions 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.

"What we should be doing is monitoring children from birth so we can detect any deviations from the norm at an early stage and action can be taken". Who said that? Joe Stalin? Adolf Hitler? Orwell's "Big Brother"? The Spanish Inquisition? Generalissimo Francisco Franco Bahamonde? None of those. It was Dr Colin Waine, chairman of Britain's National Obesity Forum. What a fine fellow!


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