Saturday, August 04, 2007


I don't think most people will be much surprised by the finding below but the interesting question is why. The finding actually surprised me somewhat because the content of most media health messages is a quite obsessive repetition of the mantra that fat and salt are bad for you -- messages that have NO support in well-conducted longditudial studies. So is there some other beneficial content in media health messages? Maybe. Though not being able to read warning signs and labels is more likely to have something to do with it. But I think that we should first look more closely at the study below before we draw any conclusions.

It is actually a more sophisticated study than most epidemiological studies in that it DOES control for education and social class. While education and social class are important, however, two other important social stratification variables not considered are income and IQ -- and neither of those have really close proxies in education and social class. Some well-educated people are poor and some rich people are not very bright, for instance. So, applying Occam's razor, I conclude that the study shows simply that poor people die younger. Given their lesser access to good medical care -- PARTICULARLY in socialized medicine systems such as Britain's NHS -- that is not at all surprising.

Another worthwhile possibility to consider is that illiterate or semi-literate people have to take jobs that are more dangerous in various ways

Health Literacy and Mortality Among Elderly Persons

By David W. Baker et al.

Background: Individuals with low levels of health literacy have less health knowledge, worse self-management of chronic disease, lower use of preventive services, and worse health in cross-sectional studies. We sought to determine whether low health literacy levels independently predict overall and cause-specific mortality.

Methods: We designed a prospective cohort study of 3260 Medicare managed-care enrollees in 4 US metropolitan areas who were interviewed in 1997 to determine their demographic characteristics, chronic conditions, self-reported physical and mental health, and health behaviors. Participants also completed the shortened version of the Test of Functional Health Literacy in Adults. Main outcome measures included all-cause and cause-specific (cardiovascular, cancer, and other) mortality using data from the National Death Index through 2003.

Results: The crude mortality rates for participants with adequate (n = 2094), marginal (n = 366), and inadequate (n = 800) health literacy were 18.9%, 28.7%, and 39.4%, respectively (P < .001). After adjusting for demographics, socioeconomic status, and baseline health, the hazard ratios for all-cause mortality were 1.52 (95% confidence interval, 1.26-1.83) and 1.13 (95% confidence interval, 0.90-1.41) for participants with inadequate and marginal health literacy, respectively, compared with participants with adequate health literacy. In contrast, years of school completed was only weakly associated with mortality in bivariate analyses and was not significant in multivariate models. Participants with inadequate health literacy had higher risk-adjusted rates of cardiovascular death but not of death due to cancer.

Conclusions: Inadequate health literacy, as measured by reading fluency, independently predicts all-cause mortality and cardiovascular death among community-dwelling elderly persons. Reading fluency is a more powerful variable than education for examining the association between socioeconomic status and health.

Arch Intern Med. 2007;167:1503-1509

Thanks be unto mice

The number of scientific experiments conducted on animals has declined considerably over the past 30 years. The trend, however, has been reversed recently. The total has risen in each of the past five years and new data released by the Home Office this week show that the 2006 figure exceeded three million for the first time since 1991.

This has angered even the more considered elements of the animal rights lobby. The RSPCA pronounced itself furious and shocked, while the Dr Hadwen Trust, which supports medical research with nonanimal methods, blamed the Government's "ethical negligence". Its message was clear: scientists might talk about replacing, reducing and refining animal experiments, but this is mere lip service. The statistics tell a tale of more animal suffering.

This view might look compelling, but it is not founded in logic. A rise in the raw number of animal procedures does not necessarily mean that medical researchers are being cavalier. As it happens, the upward trend has a perfectly reasonable explanation that has nothing to do with callous indifference to animal welfare.

A close look at the Home Office figures makes this plain. The recent rise in animal use is almost entirely explained by the growing importance to science of genetically modified mice. The number of experiments that use these has more than quadrupled since 1995, to reach 1.04 million last year. One in three animal procedures now involves a GM mouse.

This headline figure, though, is a little misleading. The birth of every GM animal must be recorded as a scientific procedure in the Home Office statistics, even if it is never used in an experiment. Two-thirds are created purely to maintain breeding colonies or to provide cells, and are never given drugs or surgery. Many suffer no ill-effects from being genetically altered. Take them out of the equation and animal experiments would have continued to fall.

That said, it is beyond dispute that the number of GM animals used actively in research is rising and will continue to do so as more genes that influence disease come to light. But that is because these mice - and 97 per cent of GM animals are mice - allow scientists to answer medical questions that could not even have been asked a decade ago.

Conditions with a genetic contribution, such as diabetes, can now be modelled effectively by manipulating the genes of laboratory mice. These animals can then be used both to understand the disease process and to test new drugs. Such work is already having important results: treatments for incurable disorders such as muscular dystrophy that have been developed using GM mice are close to beginning clinical trials.

Such insights, regrettably, cannot be obtained in any other way. Scientists are using more GM mice not because they have become hard-hearted but because they are the best available tools for a certain kind of research of exceptional medical promise. From a patient perspective, the increasing number of GM mouse experiments is something to be welcomed. It means that science is closing in on the genetic origins of disease and thus on new approaches to therapy.

The development of nonanimal methods is of course welcome, and when such techniques have been validated it is right to use them. The number of nonGM animal procedures in research, indeed, has come down from 2.27 million in 1995 to 1.65 million last year. Further investment is appropriate, but too narrow a focus on reduction would mean abandoning new animal models just as they are becoming most useful. Science must be serious about both medical progress and animal welfare, but that may mean using more animals when necessary, and fewer when it is not.



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].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


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