What causes asthma: pollution or cleanliness?

Several months ago I wrote a post called, "Is there a link between asthma and air pollution," in which I posed the question to you in a poll: "Does air pollution cause asthma?" I believe it was something like 67% of my readers said they did believe pollution does cause asthma.

I purposely left my question vague because I have noted many people confuse "cause" and trigger." Bellow I will pose a few definitions:

Asthma cause: Anything that turns on the asthma gene causing a person to develop asthma.

Asthma trigger: Anything that results in a person having an asthma attack. There are many asthma triggers, as you can see by this link here.

I think the following stat from AAAAI.com had many people drawing to the conclusion that pollution caused asthma:

• The prevalence of asthma increased 75% from 1980-1994.3
• Asthma rates in children under the age of five have increased more than 160% from 1980-1994.3
• It is estimated that the number of people with asthma will grow by more than 100 million by 2025.2
• And, not mentioned at AAAAI.com is the statistic that a majority of the 3,384 asthma deaths, and a majority of cases of asthma near death experiences occur in cities, where pollution rates tend to be higher.

All of these statistics had many people leaning toward the notion that pollution causes asthma. Now, while this "theory" still could be true, many statistics and pollution studies done over the past 15 years show that even in cities where pollution rates have declined, asthma rates have continued to increase.

So, is the politically correct notion that pollution causes asthma true? It is possible, as there was a new study released recently that showed that moms who breath in polluted air before their child is born are more likely to give birth to children with asthma.

However, more and more scientists have been questioning the notion that pollution causes asthma, and looking at a new theory that says that it isn't so much pollution that turns on the asthma gene, but the fact that we are too clean.

It was in the late 1990s that scientists started looking at asthma statistics world wide that showed impoverished nations where most people lived on farms had the same allergens and pollution levels of U.S. cities, yet had lower rates of asthma

These statistics sent scientists to theorize that perhaps asthma is spreading so fast because modern technology, showers, antibacterial soap, antibiotics and the like are also spreading fast. They came to suspect that asthma is caused because we are to clean.

This was also the conclusion draw after studies showed the following resulted in fewer incidences of asthma:

• Children who are breast fed
• Children who attend day cares
• Children of large families
• Children who do not take antibiotics in first three months of life
• Children who are not born by c-section

In all these cases, children are exposed to bacteria a newborns immune system needs to develop properly.

This theory, now poplar in the scientific community, is called The Hygiene Hypothesis. I wrote a post about this recently, and if you click here I will morph you to my latest asthma post.

Keep in mind here I am not drawing to any conclusions here, just placing all the latest wisdom on the table. When you have are finished you can participate in the poll at the top of my blog. I want to see if your opinion as to what causes asthma has changed.

Thank you, and have a wonderful day.

The Hygiene Hypothesis: Does Cleanliness Cause Asthma? by Rick Frea Wednesday, June 17, 2009 @ HealthCentral.com

Asthma-like symptoms were recorded in the earliest forms of writings going all the way back 5,000 years. With all that history, it's hard to believe we only recently started coming up with viable "guesses" as to why some people develop asthma. My favorite guess is the hygiene hypothesis.

The ancient Romans found a link between cleanliness and disease, and created aquaducts to supply clean water and bath houses to give people a place to wash up. When bacteria were discovered in the 1800s, the Roman's were proven correct.

Since the discovery and understanding of how germs cause disease, there has been an effort by society to stay clean. But is it possible that we have become so clean that we have opened ourselves up to suffering new kinds of diseases? Is it possible that civilization causes asthma? According to the Hygiene Hypothesis, the answer is yes.

Many scientists speculated that the same things that trigger acute asthma attacks are the same things that cause asthma. In that sense, many scientists looked at pollution as a main cause. Asthma rates increased by 75% between 1980 and 1995. Most asthma deaths (80.2% according 1989 stats) occured in highly populated urban areas as well.

However, while pollution has been proven to "trigger" asthma, other studies show that in areas where pollution levels are decreasing asthma rates are still on the rise.

This research encouraged David P. Strachan to look in a unique direction. He made an observation that in Third World nations where people lived in poverty, on farms, and were rarely innoculated from infectious disease, asthma rates were lower than in developed nations like the U.S., Europe and Australia with high concentrations of the population living in urban areas and high rates of childhood vaccination.

He also observed that the same pollution and allergens that exist where asthma rates are low also exist in places where asthma rates are high.

He then proposed the Hygiene Hypothesis in the British Medical Journal in 1989. This hypothesis, or educated guess, is that the asthma gene is not turned on because we are too dirty, but because we are too clean. He came to this conclusion after looking at studies that revealed people who live near farm animals were less likely to develop asthma. Since people in many Third World nations work in farming or are often around animals, they are exposed to bacteria and parasites common around these animals.

Likewise, studies revealed people exposed to pig and cattle parasites and bacteria in the first three months of life (when their immune system is still developing) were less likely to get asthma. According to The Medical College Of Wisconsin, these studies and observations "led several researchers to conclude that organisms in cattle dust and manure may be the stimuli that their immune systems needed to fight off asthma."

Also, several studies (like this one) showed that children exposed to pet dander (proteins in pet saliva and skin, but not pet hair) were less likely to develop asthma. This seems counterintuitive, since it is common (and correect) advice for people and children with asthma and allergies to either get rid of their pets or to, at least, keep them out of the bedroom and off the furniture.

So why would this be? Consider this: asthma is an autoimmune disease. When we are born, our immune systems are still developing. Considering that our immune system doesn't fully mature until we are about 3 months old, it is prior to this time that something "might" occur to turn the so-called asthma gene on -- if a person has the asthma gene.

The hygiene hypothesis surmises that if we are not exposed to certain bacteria and parasites for our immune systems to battle, our immune systems get "bored" and may, instead, react to and create antibodies against normally harmless substances such as pollen and dust, i.e. allergens.

Once the asthma gene is turned on, you, more than likely, will have asthma. Many people will notice asthma symptoms in childhood as they are exposed to their asthma triggers. However, many others will have symptoms so mild during childhood they won't even realize they have it until they are adults (adult onset asthma).

Per this hypothesis, there are people that may be at higher risk of developing asthma as well as events more likely to trigger its development, such as:

• Premature babies (they have immature immune systems)
• Respiratory Syncitial Virus
• Antibiotic usage in the first months (they kill normal bacteria as well as bad bugs)
• Children born by C-section (no exposure to bacteria in the vaginal canal)
• Not breast feeding (no exposure to bacteria from mom)
• Smoke inhalation
• Obese mothers (fat may hamper development of the lungs)
• Pregnant women breathing pollutants (may cause asthma in the womb)
• Stress

However awkward this sounds, it all makes sense to me. What do you think?

Does pollution cause asthma?

There is a lot going around these days that pollution is the cause of asthma. While asthma rates are marginal in 3rd world nations, they are growing in industrialized nations, particularly large cities like New York and Chicago. The question I would like to toss out today is this: is pollution the real culprit?

Now, unlike some people, I have no bias either way. If asthma is caused by pollution it’s caused by pollution. But before I come to any conclusion I like to have all the facts on the table. I don’t like to believe in one theory over another just because one makes me feel better, or is more popular.

Is pollution the cause of asthma? Lets look at the facts.

You can look back at the 1800s when there was horse poop on the streets, coal and wood fires burning in every household, smoke billowing through the air. If you take a deep breath you can smell the smoke, smell the poop. I’m sure all this had a negative impact on any asthmatic in the day.

If you listen you can hear flies buzzing around your head as they swoop down to lay another egg on the horse dung. Whatever diseases they are spreading you can only imagine.

Today, however, we have no such horse poop. We have far fewer coal and wood fires, although they do still exist. However, the horse poop is exchanged for car fumes.

In the 1800s, however, there was no technology available to clean the air. There were no filters. There were no concerns about air pollution. You simply didn’t think about it. But was there less air pollution in 1888 than today. Who knows?

However, we do know that there were still volcanoes that erupted and caused holes in the ozone much larger than any nuclear explosion man has ever made. We know that as a fact. We know that there have always been holes in the ozone. So any bad rays that get through now have always gotten through.

So recent studies that show that asthmatics who are exposed to ozone are more likely to have a decrease in lung function may not necessarily show that this is a new phenomenon.

Based on what I just wrote we have zero evidence that pollution is the cause of asthma, and no evidence that it is not. What we have hear is some groundwork to show that pollution existed long before industrialized nations, and we must not come to a harsh conclusion just because it’s convenient or obvious or popular.

I have been doing a lot of writing lately about asthma. This disease is a major conundrum for scientists in that it has been around longer than most diseases in recorded history and we are just now beginning to understand it.

Considering this long history, there have been a lot of truths, and a lot of false information to go with those truths. In the 1800s, for example, scientists educated doctors that asthma was definitely a psychosomatic disease, "that the disease is all in the head of the asthmatic."

Well, now we know that "theory" was pure poppycock --fiction. Sure stress can act as an asthma trigger, but it cannot cause asthma. Despite this truth, millions of hours and lots of cash was spent in an effort to treat asthma as a mental disorder.

Recently, with the high rates of air pollution, many scientists have been teaching that air pollution may be a cause of asthma. Yet new theories have been created that challenge the pollution theory.

A new theory – called the Hygiene Hypothesis – notes that the cause of asthma may be just the opposite of what the pollution theory postulates: that asthma is caused not because of pollution, but because we are too clean.

It may not be popular to go against the pollution theory, but that's exactly what RT philosophers like myself are not getting paid to do.

Stay tuned, keep your mind open, and I’ll continue to discuss this in the days to come.

Is there a link between air polution and asthma?

Is there a link between air pollution and asthma? That is a question I am going to spend the next seven days investigating, and reporting on here at the RT Cave.

What is the answer to that question? I do not know. Many of us may have an opinion in this area, but are we really right?

It is true that there is a certain level of pollution in the air, and some of it is definitely caused by the burning of coal and oil, and some of it caused by natural things like the sun and ozone.

Setting opinion aside, we have some facts documented.

We know that, according to the AAAAI.org that between 1980 and 1994 the prevalence of asthma increased a whopping 75%. There are many theories for this increase, and one of them is air pollution. But there are other theories too

Likewise, according to the authors of a book called Fatal Asthma, the incidence of asthma related deaths has increased from being "negligible" in 1930 according to asthma experts at that time, to 3,000 per year in 1998 and 5,000 per year as of 2006.

Is pollution the cause of this rise in the prevalence of asthma? Is pollution the cause of the increase in asthma related deaths?

My goal in the next week is to clear my head of any bias I have (and I ask you to do the same), and I aim to investigate this matter and come to a logical conclusion based on the facts.

However, before you clear your head of any bias you might have, take the poll at the top of this blog. Go ahead, do it right now! I'll wait here for you.

Good. Sometime in the next week I will participate in the poll too. Throughout the next week (and time permitting because I do have to work 8 of the next 10 days), I will read, study and report to you facts regarding this matter.

Next Wednesday (April 1, 2009) at midnight the poll will close, and I will announce the results next Thursday. Likewise, at that time I will give you the latest information regarding pollution and asthma, and together we'll come up with a conclusion to our question: Is pollution the reason for the increase in the prevalence of asthma?

Once all the facts are on the table we'll retake the poll and see if the results change.

Oh, and one more thing: If any of my readers has any information regarding pollution, or that shows how pollution is or is not linked to asthma, send it my way and I will share it with my readers.

Go vote! Now! And then, with an open mind, stay tuned to the RT Cave for an open minded discussion on this matter. And don't be afraid to admit you are wrong or gloat if you are right.