Inconvenient Facts
There was only one problem. As more data came in, they failed to tell the same story as the hygiene hypothesis. Children in Latin America with high rates of supposedly protective infection have even higher rates of asthma than children in western Europe. Inner-city children in Chicago and New York have quite high rates of asthma, despite unhygienic living. And the rates of asthma varied among countries with very similar histories of cleanliness—indicating that there was more to it than tidiness. For example, by 2004 Sweden’s asthma cases had increased to 10 percent, according to one international study, while the number of cases in the U.K. had soared to 20 percent.
In addition, research showed that the relation between asthma and allergy is not at all straightforward. Some cases of asthma are indeed triggered by allergies, although the consensus among researchers over the past decade is that the connection is probably not as clear-cut as the hygiene hypothesis would suggest. Still other layers of immune regulation must be involved. Maria Yazdanbakhsh, a parasitologist at Leiden University in the Netherlands, has shown that people infected with parasitic worms have very high levels of the allergy-related immune cells but very low rates of asthma, disproving a direct connection between allergy and asthma in these cases at least.
What is more, a landmark review of asthma studies in 1999 by Neil Pearce, now at the London School of Hygiene and Tropical Medicine, demonstrated that at least half of asthma cases in the general population have no connection to allergic reactions at all. These could never be explained by the hygiene hypothesis.
In fact, the same factors that the hygiene hypothesis suggests protect people from developing allergic asthma may cause them to develop nonallergic asthma. “We think that dirt protects against allergic asthma, as foretold by the hygiene hypothesis, but increases the risk of having a nonallergic form,” says Laura Rodrigues of the London School of Hygiene and Tropical Medicine, who studies asthma in Latin America. Pollutants in the air can irritate the airways and cause inflammation that leads to constricted breathing. Childhood colds, which the hygiene hypothesis suggested might help prevent development of asthma, can actually be a risk factor for asthma, especially if severe, says James E. Gern, a pediatrician who studies colds and asthma at the University of Wisconsin–Madison. “Early-life infections are an indicator of asthma risk rather than protective in any way,” he says.
Besides the hygiene hypothesis, what can explain the increase in asthma rates? Other suggested causes include a rise in sedentary lifestyle, which could affect lung strength, and the rise in obesity, which increases inflammation throughout the body. A reworking of the hygiene hypothesis that focuses on changes in the normal nondisease-causing bacteria that live inside and on the body (in the intestines or the airways or on the skin) has promise. Studies by von Mutius and others have shown that children who live on farms where cows or pigs are raised and where they drink raw milk almost never have asthma, allergic or otherwise. Presumably because the children drank unpasteurized milk and handled livestock, they have different strains of normal bacteria in their airways that are somehow more protective than those found in city kids.
But the short answer to the question of why asthma has increased, according to Pearce, von Mutius, Rodrigues and many others, is, “We don’t know.” Pearce, in particular, wonders whether modernization in general or westernization in particular may play a role. “There is something about westernization that means people’s immune systems function in a different way,” he says. “But we don’t know what the mechanism is.”
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29 Comments
Add CommentI was surprised that your article ‘Why are asthma rates soaring’ did not consider ‘The Elephant in the Article (aka room)’. The article had a large image of a blue (bronchodilator) inhaler. I understand that the only statistic that correlates strongly with asthma incidence is the use of these inhalers. Over the years there has been strong theoretical grounds for considering that this relationship is causative! My grandson (15 months) was recently given a blue inhaler for a ‘night cough’. Also these inhalers are routinely given for the common and benign symptom of wheezing (bronchospasm) in young children. Why do young children wheeze? Could it be an evolutionary mechanism for protecting an immature immune system? Other than relative airway size I know of no other proposed reason. Clearly the use of blue inhalers may circumvent this mechanism leading to lifelong problems and the life threatening condition of Status Asthmaticus, which only seems to occur in patients on these inhalers. I am not aware that this hypothesis has been tested. Could this be due to research funding in this field mainly coming from pharmaceutical companies, who understandably prefer to promote research that furthers their sale of their drugs rather than damage a nice little earner such as the blue inhaler? I understand that current paediatric practice is to strongly encourage the use of these inhalers in young children with wheezing and also night cough. Whilst I am not aware of any evidence that not using these inhalers in young children would reduce asthma incidence, all I can say is that in the last 10 -15 years of my 37 years as a medical practitioner (now retired) I have totally avoided initiating these inhalers in this vulnerable age group without any adverse incident.
Reply | Report Abuse | Link to thisFollowing a recent discourse concerning asthma at the Royal Institution, London, I found abundant evidence on the web for my contention that it could be dealt with by attention to manganese nutrition. Go to scienceuncoiled.co.uk for an introduction to my researches.
Reply | Report Abuse | Link to thisI would have to agree with AJ_jenkins. As it is pointed out by the article, it is seen to have a relation to the western culture. Medicine is the go to for releaving any type of discomfort, a quick fix is valued more than a long-term treatment. I believe that the causation of inbreading(not so much from brother to sister or direct family members but of same genes in a grand scale) has minimized the variety of alterations or mutations within the geen pool. Areas that are more one-sided seem to have more medical problems than those with diverse backgrounds and communities. Also the use of external chemicals, such as those seen in food production, have weekened our biotic makeup and steered us away from organic consumption that is filled with radiation and ions that are unseen in processed/GM produce but beneficial to human health.
Reply | Report Abuse | Link to thisI found Veronique Greenwood’s review of increasing asthma rates very honest, transparent and refreshing. It was also – with one exception – very thorough.
Reply | Report Abuse | Link to thisIt has now been 20 years since Dr. Roger Bone, a now deceased pulmonologist and associate editor of the Journal of the American Medical Association (JAMA), first suggested that an infectious disease pandemic, specifically Chlamydia pneumoniae infection, could explain increasing rates of asthma worldwide (Bone RC. Chlamydial pneumonia and asthma: a potentially important relationship. JAMA. 1991; 266: 265.). Since then an increasingly robust science supports this possibility. For a repository of over 60 scientific articles, editorials, abstracts and letters on this topic, link to: http://www.dean.org/Foundation/research/asthma-references.aspx. In particular, item #57 “A theory explaining time trends in asthma prevalence” would have been a welcome addition to this otherwise excellent article.
But I do not blame Ms. Greenwood for this omission. The expert asthma research community, upon whom she presumably depends for her information, has been peculiarly reluctant to talk about the potentially breakthrough evidence that at least some asthma (it appears to be the worst, most treatment resistant form) is related to a treatable infection. Why this reluctance? I have no direct evidence for underlying motivation, only for the fact of neglect. I do believe, however, that it is relevant to consider the facts that pharmaceutical companies drive the asthma research agenda – and that it is more profitable to control a disease than to cure it.
Coincidentally, the latest "Earth Beat" radio show, "The Dirt Show", includes an interview with Katherine Ashenburg (the author of a book on the history of hygiene), who discusses the "hygiene hypothesis" and describes the research on the differences between asthma cases in East and in West Germany that seems to corroborate it. "Earth Beat" is an environmentalist Radio Netherlands Worldwide program and the said show can be listened to at http://www.rnw.nl/english/radioshow/dirt-show-0.
Reply | Report Abuse | Link to thisMy guess is that the cause is over-diagnosis.
Reply | Report Abuse | Link to thisAll 3 of my children were diagnosed with asthma by our family doctor, and treated with medication. I was always quite suspicious of this, since none of them really had any problems in sports or in general. It was discovered through testing in the doctor's office with a cheap little test unit.
Fast forward a few years. We decided to take them to the University of Michigan to a specialist. There, with better testing equipment, all three were cleared. They don't have asthma and likely never did have it.
Soccerdad, despite your having three kids, your tale refers to a single doctor, and is at best a single anecdote.Overdiagnosis may have occurred in that case, but no valid conclusions can be made about the broader situation from just that.
Reply | Report Abuse | Link to thisTo the extent that diagnosis of asthma is 'judgement call' by all types of physicians there may be a wide discrepancy in the veracity of diagnosis.
Reply | Report Abuse | Link to thisLikewise, anyone prescribed the use of an inhaler would be considered to be asthmatic: it should be expected that there'd be an extremely high correlation between the incidence of asthma and inhaler user. That correlation does not infer causation.
I have to say I disagree with your hypothesis here AJ. I believe that you and H1 are onto the correct answer here and it is that the western world has an overabundance of doctors thus making detection and records more accurate. I don't deny that drugs in vast quantity, especially to a young developing body, are a bad thing but I would assume that lung scarring would be something the FDA would check on a drug we breathe. I had asthma as a kid and I grew out of it. I think maybe its something else you eluded to which is that young people are going through so many changes that maybe certain parts of the body have trouble coping with catching up. Quite possibly it has to do with food source and steroid use in animals. Maybe parts of our bodies are growing faster than the rest of us and it takes several years to catch up. That would also help explain why so few adults are diagnosed with asthma or still have the effects after the end of puberty. If you look at it from that standpoint it also would make sense that the year the jump began was 1980 being that it was under a decade from the real widespread practice of steroids and antibiotics in our animals. Agree to disagree I suppose.
Reply | Report Abuse | Link to thisAnother factor that might be considered is the mind/body connection re stress.
Reply | Report Abuse | Link to thisI find it interesting that the article states that there is a lesser rate of occurances in lesser population densities ie a farm lifestyle and Sweden ( aprox ( 5 million ) and the UK ( 60 million + ) these densities would almost certainly co relate with higher stress levels on average.
Further on this line of thinking it might also be considered as to whether certain personality types that find srtess more difficult to deal with would be more succeptible to asthma.
Coping and becoming more peaceful might therefore have as much to do with better health here as the othe factors mentioned .
thanks
Quote: “We don’t know.”
Reply | Report Abuse | Link to thisAnswer: Could? it be simple increased red blood cell production / erythrocytosis ? Theophylline used to treat asthma is **specifically** used to lower red blood cells in other diseases. In asthma the erythrocytosis found is considered SECONDARY to asthma but is treated with theophylline which "coincidentally" specifically lowers red blood cells ?
In that case, wouldn't asthmatics necessarily also be anemic?
Reply | Report Abuse | Link to thisSomeones link the increase in asthma rates with the too early introduction of cereals in baby's food (before one year of age). Serious studies stablish a negative correlation between intestinal infections during childhood and asthma; in countries where Diesel motored vehicles abund, the particulates and NO in the Diesel exhaust gas are also blamed for. Who knows ?
Reply | Report Abuse | Link to thisAnemic ? I don't see the connection. Erythrocytosis is a subcategory of hemochromatosis. Asthmatics commonly present with erythrocytosis. This increase of red blood cells they consider to be SECONDARY to the asthma. The asthma CAUSES the increased red blood cells. WHEN theophylline is used the asthma is treated AND "coincidentally" the red blood cells go down. Theophylline is used in OTHER diseases to SPECIFICALLY lower red blood cells. Lowering red blood cells in someone with INCREASED red blood cells would very likely bring them down into a NORMAL hemoglobin / red blood cell count.
Reply | Report Abuse | Link to this"Erythrocytosis is a subcategory of hemochromatosis"
Reply | Report Abuse | Link to thisPart of the theory is below.
The excess iron would lead to increased red blood cells / erythrocytosis.
"Allergies, Autism Linked To Excess Dietary Iron
U. Padhye
Abstract
Autism and other closely related disorders under Pervasive Developmental Disorder (PDD) umbrella have grown exponentially in past 30 years in the United States. During the same period of time Iron consumed by
infants rose exponentially. This research sheds the light on connection between increased iron consumption and autoimmune disorders such as Allergies, Eczema, Asthma, Autism and PDD disorders."
Sorry I misunderstood - thanks for the clarification.
Reply | Report Abuse | Link to thisWhat statistics are being used to support the assumption that asthma rates are soaring?
Reply | Report Abuse | Link to thisFor example, with a quick search I found:
http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&lv=list.listbyalpha&r=219646&subtop=381
"In adults, an increase in asthma prevalence rates (i.e., lifetime diagnosis) is evident from 1997 to 2001, with some decrease after 2001 and subsequent increase after 2003 (Exhibit 5-29, panel B). The prevalence rates range from a low of 85 cases per 1,000 in 1999 to a high of 126 cases per 1,000 in 2008. "
"In 2008, just over 10 million children within the U.S. (age 0-17 years) were reported as ever having a diagnosis of asthma and over 4 million reported experiencing an asthma episode or attack during the previous 12 months. As shown in Exhibit 5-31, asthma prevalence rates increased approximately 4 percent per year between 1980 and 1996. Rates in subsequent years (1997- 2008), reported in two of the three asthma categories (current asthma and asthma attack prevalence), show no sharp upward or downward change through most of the time period."
I am a physician and have been aware that something was seriously wrong with the Western Diet for my entire career. My frequent questions could not be adequately answered by the experts until fairly recently. I have been very impressed with the importance of the omega 3 to 6 ratio to explain much of this. I like to understand problems down to the molecular level and this helps on many levels. In the short run there is often a major difference in the behavior of signaling eicosenoids (C-20 lipid molecules)depending on whether they were made from omega 3 or omega 6 precursors. In the longer run the composition of the lipids in membranes has an impact on the behavior of enzymes and receptors embedded in the membranes.
Reply | Report Abuse | Link to thisThe balance of omega 3 and 6 lipids has been radically altered in the Western Diet over the last few decades. You are what you eat. You are also what you eat ate. We need to look at changing disease frequencies with these thoughts in mind. Unfortunately our dependence on the financing of health research by industry tends to ignore lines of research that do not lead to lucrative patents. Industrial farming, the prepared food industry, and the big pharmaceutical industry are not financially inclined to change the status quo of the Western Diet. For the rest of us we are talking about our health and 1/6th of the GNP going into health care. Looking at the lipids in research subjects as part of epiodemologic studies is not prohibitivly expensive and may well help to lead us to better understanding. That is what science should be about.
"Dear Secretary Vilsack:
Reply | Report Abuse | Link to thisA team of senior plant and animal scientists have recently brought to my attention the discovery of an electron microscopic pathogen that appears to significantly impact the health of plants, animals, and probably human beings. Based on a review of the data, it is widespread, very serious, and is in much higher concentrations in Roundup Ready (RR) soybeans and corn-suggesting a link with the RR gene or more likely the presence of Roundup. This organism appears NEW to science!
More on GMO Dangers Here
This is highly sensitive information that could result in a collapse of US soy and corn export markets and significant disruption of domestic food and feed supplies. On the other hand, this new organism may already be responsible for significant harm (see below). My colleagues and I are therefore moving our investigation forward with speed and discretion, and seek assistance from the USDA and other entities to identify the pathogen's source, prevalence, implications, and remedies.
We are informing the USDA of our findings at this early stage, specifically due to your pending decision regarding approval of RR alfalfa. Naturally, if either the RR gene or Roundup itself is a promoter or co-factor of this pathogen, then such approval could be a calamity. Based on the current evidence, the only reasonable action at this time would be to delay deregulation at least until sufficient data has exonerated the RR system, if it does.
For the past 40 years, I have been a scientist in the professional and military agencies that evaluate and prepare for natural and manmade biological threats, including germ warfare and disease outbreaks. Based on this experience, I believe the threat we are facing from this pathogen is unique and of a high risk status. ......
...A diverse set of researchers working on this problem have contributed various pieces of the puzzle, which together presents the following disturbing scenario:
Unique Physical Properties
This previously unknown organism is only visible under an electron microscope (36,000X), with an approximate size range equal to a medium size virus. It is able to reproduce and appears to be a micro-fungal-like organism. If so, it would be the first such micro-fungus ever identified. There is strong evidence that this infectious agent promotes diseases of both plants and mammals, which is very rare........"
http://www.gmwatch.org/index.php?option=com_content&view=article&id=12899:researcher-roundup-or-roundup-ready-crops-may-trigger-animal-miscarriages-
Next question
http://www.gmwatch.org/index.php?option=com_content&view=article&id=12899:researcher-roundup-or-roundup-ready-crops-may-trigger-animal-miscarriages-
Reply | Report Abuse | Link to this"....Unique Physical Properties
This previously unknown organism is only visible under an electron microscope (36,000X), with an approximate size range equal to a medium size virus. It is able to reproduce and appears to be a micro-fungal-like organism. If so, it would be the first such micro-fungus ever identified. There is strong evidence that this infectious agent promotes diseases of both plants and mammals, which is very rare.
Pathogen Location and Concentration
It is found in high concentrations in Roundup Ready soybean meal and corn, distillers meal, fermentation feed products, pig stomach contents, and pig and cattle placentas........"
Newly discovered micro-fungus! Next question.
Article states that asthma started spiking, like so many other afflictions, in the 1980's. Glyphosate was invented in the 1970's. Seems like a reasonable time set for a ramped exposure to the population in general.
Reply | Report Abuse | Link to thisI wouldn't be surprised if similar discoveries link this micro-fungus and other yet unidentified organisms to all sorts of epidemic spikes.
What are you suggesting regarding the "omega 3 to 6 ratio"? Are you suggesting that one or the other is too low in the "Western Diet"? Are you suggesting that the balance of omega 3 to 6 more important than the amounts ingested of either?
Reply | Report Abuse | Link to thisI like to understand problems at the conceptual level. In my personal experience I happened to have been prescribed Lovaza a few years ago to reduce triglycerides, coincidentally following 9 months of chemo. Starting with 1G doses, within one week I noticed a dramatic restoration of intellectual capabilities (that I hadn't realized I'd lost). I now attribute that improvement to possible repair of damage to the insulating neuronal axon myelin sheaths suffered as a result of severe anemia due to chemo effects.
While that result may seem to have nothing to do with asthma (or Allergies or Eczema, or Autism and PDD 'umbrella' disorders), but IMO anything that can make such a dramatic improvement in neuronal performance as I'd experienced should be investigated in relation to afflictions that may be related to neuronal conditions.
After reading the article and all the prior comments, I am alone in thinking air pollution is having an effect on people that is transmitted to their off spring in conjunction with breathing more air pollution. One thing is for certain, air pollution is killing countless of thousands. Air pollution, lung disease, asthma, and other rising respiratory disorders all seen to have one think in common and that is breathing. Now consider communities near or down wind of the highly pollutant industries and compare their statistics of respiratory illness.
Reply | Report Abuse | Link to thisI believe the smoking gun is apparent unless the studies are funded by industries moneys. Not saying this research is however, universities, state sponsored research, industries funded research scientist, etc all have a vested interest in averting the truth. Or have we forgotten about all the scientific evidence presented to congress and other committees stating, cigarette smoking is not addictive and absolutely does not cause lung cancer. I guess we can say the exact same thing regarding coal dust, asbestos, DDT, etc and all shared in similar denials only later to discover the dangers were known many of years earlier.
I had the same problem with one of my sons and the same doctor that diagnosed asthma is the one that later said the diagnosis was incorrect. That doctor said it is easy to incorrectly diagnose asthma and that you should always monitor the situation and have a second opinion and follow-up testing periodically as more is learned.
Reply | Report Abuse | Link to thisI've noticed a variety of health improvements since cutting back on meat and starting to take flax seed oil. Unlike fish oil it has more omega 3 than omega 6. I don't have asthma but a varitey of other issues have gotten better. It isn't a cure all though.
Reply | Report Abuse | Link to thisHow about the increase in pollution? We live in a sea of Petro Chemicals.
Reply | Report Abuse | Link to this10 YEARS AGO HARLEM NY HAD THE HIGHEST ASTHMA RATES-POOR PEOPLE WITH OLD CARPETS? REASONS FOR ASTHMA: A DIET WEAK IN THINGS TO RREVENT ALLERGIES AND COLDS, UNCLEANLINESS, CIGARETTE SMOKE, POLLUTENTS IN THE AIR.
Reply | Report Abuse | Link to this10 YEARS AGO HARLEM NY HAD THE HIGHEST ASTHMA RATES-POOR PEOPLE WITH OLD CARPETS? REASONS FOR ASTHMA: A DIET WEAK IN THINGS TO RREVENT ALLERGIES AND COLDS, UNCLEANLINESS, CIGARETTE SMOKE, POLLUTENTS IN THE AIR.
Reply | Report Abuse | Link to thisSince my original comment (3/25/11), my approach has amassed much supporting evidence - see www.scienceuncoiled.co.uk or request 'Trace elements in human nutrition' from michaeltdeas@gmail.com. Asthma could easily be eradicated.
Reply | Report Abuse | Link to thisMichael T Deans MA MSc