Thursday, June 07, 2007


I am extremely dubious about the study below. I accept that the incidence of asthma has risen in recent decades and I accept that a probable cause of that is insufficient challenge to the immune system in early childhood. What I do NOT accept is that smoking has increased in recent years. Everything I have read tells me that decades of health warnings have gradually had an effect and that smoking has DECREASED in recent decades. The article below asks us to believe the opposite of that. I think it is just another politically correct attack on smoking. How the author jimmied her data to get her desired conclusion I think I know (I suspect that she ignored recent decades and just looked at the century-wide trend) but I can't be bothered wasting my time by looking into it. This is really epidemiology at its worst. Smoking MAY aggravate asthma -- I expect it does -- but this study does not prove it

Environmental tobacco smoke and the epidemic of asthma in children: the role of cigarette use

By Renee D. Goodwin


Background: Asthma is the most common chronic disease affecting youth worldwide. The prevalence of asthma has increased at least 3-fold during the past several decades. The reason for this increase remains unknown.

Objective: To examine one possible factor that may be affecting the increase in prevalence of asthma among youth.

Methods: Data on the incidence of asthma among youth were aggregated using the National Health Interview Survey (sample of 4,500 children) and were compared on an ecologic level with data on cigarette consumption in the United States from 1900 to 2003 from the American Lung Association.

Results: Our results suggest a parallel increase in the rates of cigarette use among adults and asthma in children. These findings show an increase in cigarette use during the past 4 birth cohorts, with subsequent leveling off at a population level with a progressively more prominent increase in cigarette use among women in the United States.

Conclusion: We present one possible factor that may be contributing to the epidemic of childhood asthma. We hypothesize that (1) there has been a marked increase in smoking during the past century, (2) this increase in smoking has resulted in a substantial increase in exposure to environmental tobacco smoke among children, and (3) increased exposure to environmental tobacco smoke has contributed to the increase in childhood asthma. Data on trends in cigarette use among adults and asthma prevalence among children during the past century are presented as ecological evidence in support of this hypothesis. Future studies will be needed to confirm these findings with community-level analyses in a variety of geographic regions.

Annals of Allergy, Asthma and Immunology, 2007, vol. 98, no. 5, pp. 447 - 454

The blind to see again?

A routine operation to restore the sight of people with the most common cause of blindness will be available within a decade, scientists believe. A team of British doctors said that a groundbreaking stem-cell treatment for age-related macular degeneration (AMD), which affects a quarter of people over 60 to some degree, should become widely available. The condition is responsible for the blindness of 14 million Europeans. The doctors are recruiting patients for the first clinical trials, scheduled to take place within five years. The team said that, after earlier studies, they were confident of success.

AMD is caused by the failure of retinal pigment epithelial (RPE) cells - the support cells under the retina that process light. The macula - the central area of the retina - then degenerates and gradually knocks out central vision. The doctors from University College London, Moorfields Eye Hospital in London and the University of Sheffield have already repaired the vision of a handful of patients with AMD using cells from the patients' own eyes. The London Project to Cure AMD, which was launched yesterday with 4 million pounds funding from an anonymous American donor, intends to carry out the same operation using retinal cells grown in the laboratory from embryonic stem cells. Stem cells are immature, dormant cells with the ability to turn into different cell types. Embryonic stem cells are obtained from early-stage embryos the size of a pinhead.

There are two types of AMD: "wet" and "dry". While much progress has been made in tackling wet AMD, which is characterised by leaking blood vessels and accounts for 10 per cent of cases, no treatment is available for dry AMD. It is believed that the new development will offer hope even to patients with the dry form.

Lyndon da Cruz, a consultant ophthalmic surgeon at Moorfields Eye Hospital, has carried out an operation in a few patients with wet AMD to take cells from the healthy periphery of the eye and transplant them into the affected area. The procedures have been successful but are associated with complications, take more than two hours and require two operations. To make it quicker, easier and more widely available researchers at the University of Sheffield have grown RPE cells from embryonic stem-cell lines. The hope is that this can be processed into a layer that can be injected into the patient's eye during a simple 45-minute operation. Tests of the laboratory-grown RPE cells in rats with AMD showed that they restored vision.

Professor Pete Coffey, the project director from the Institute of Ophthalmology at University College London, said that although they had grown RPE cells successfully they now needed to make sure that the cells were safe enough to be used in humans. "Using stem cells - which are far more adaptable - can only improve success of what has already been achieved and in addition establish this as a global therapy. "The goal is within five years to have a cohort of patients to put the cells into," said Professor Coffey, whose team is preparing the laboratory-derived cells for transplant. Given that AMD could affect up to one third of the population by 2070, with the majority suffering from dry AMD, the benefits could be substantial. "The potential to create a treatment strategy for this condition is critical and may have a major impact on vision loss," Mr da Cruz said.

He added that if in ten years the proposed 4mm by 6mm transplant patch of stem cells was not in global use, something major would have failed in the research. "We have the RPE, we have the evidence that doing this can restore vision. [We are dealing with] practicality issues rather than a big unknown."

More operations are also planned with patients' own cells in those suffering from dry AMD to test the procedure's effectiveness. Barbara McLaughlan, from the Royal National Institute of Blind People, said that taking the research from the laboratory into human trials was exciting. "This is particularly good news for the 150,000 people in the UK with dry AMD which currently has no treatment," she said. "However, even if all goes well with this project, potential treatment being made available on the NHS is still five to seven years away."

Last year The Times revealed that thousands of patients whose sight could be saved by the new drug Macugen were being denied treatment on the NHS on the ground of cost. Later an insurance company offered to cover the cost of drugs for older patients for an annual premium equal to their age in years.



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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