The Purpose of the Appendix

We are all born with one and for many of us, the first time we are aware of it is when it starts causing us serious pain. Like so many people my appendix was removed a long time ago after becoming inflamed. Appendicitis is a very painful condition which typically leads to surgery.

Left untreated, appendicitis can result in sepsis and even death so when my own appendix was removed I was pretty glad to see the back of it. I was told by my mother-a nurse- that it had no purpose anyway, a viewpoint backed up by my doctors and the prevailing wisdom of the time.

The appendix was thought to be a useless remnant of our long evolution, shrinking gradually over time as a result of our changing diets.
However, recent research suggests that may not be the case at all. Far from being a useless leftover from the days we foraged the land for fruit and grain, the appendix may actually perform certain important functions and that it is far from redundant.

According to recent research, the appendix may be responsible for repopulating the gut with good bacteria which aids digestion and immunity.

Structure of the Appendix

The appendix which is a pouch shaped organ around four inches in length is located on the lower right hand side of the abdomen attached to the large intestine. It is not certain why it happens but the appendix can often become infected, inflamed and rupture. When this happens, a severe pain is experienced in the lower right part of the abdomen and surgical removal may be necessary.

Evolution of the Appendix

Charles Darwin is among the many scientists and doctors who believed that the appendix was no more than a vestigial organ and many science books still refer to it as such. It was believed to help our ancestors to digest tree bark in the days when our diets were not quite as varied as they are now.

Of course, tree bark is not found on many menus these days leading scientists to believe that the appendix was redundant. However, researchers at Duke University who recently set out to investigate the functions of the appendix believe that Darwin and the others were wrong all along. (1)

Evolution and research?

According to the Duke researchers and their collaborators at Arizona State University, the appendix does indeed perform a useful function for our health and that it is far more than a forgotten and needless evolutionary remnant.
According to their research, the appendix appears in nature far more often than we previously realized and it has also been around for a lot longer than anybody had ever suspected.

William Parker Ph.D, the study’s senior author suggests that it may be time to reassess the traditional view that the appendix serves no purpose and that the textbooks that still refer to it as a vestigial organ are due to be corrected. In their groundbreaking research, Parker and his colleagues discovered that the organ had evolved more than once over the course of animal history.

It evolved once among the marsupials of Australia and again in rodents, certain primates and us humans. They estimated that the appendix had been around in nature for over 80 million years which is far longer than Darwin’s theory would lead you to predict.

Charles Darwin believed that the human appendix was an evolutionary remnant of a much larger structure known as a cecum. He theorized that the cecum was needed by our ancient ancestors to properly digest their food.
The study conducted at Duke University found several major issues with the theory. Firstly, there are still a few living species of animal that have a cecum with their appendix attached to it. These include lemurs, rodents and flying squirrels.

Another problem is that the appendix is much more widespread in nature than Darwin believed. Darwin thought it only appeared in a tiny handful of the animal population but we now know that over 70% of primate and rodent families also have an appendix.

What is the Purpose of the Appendix?

In 2007, the research team at Duke University published their original research in which they proposed that the appendix served a vital function. They claimed that the appendix was a safe haven for good bacteria or ‘gut microflora’ to hang about until it was needed by the gut for repopulation following illness like a bad bout of dysentery or diarrhea.

For Digestion and Immunity

The digestive system is home to billions of bacterium which play an important role in digestion. When we suffer illness or attack from disease, many of these healthy types of bacteria are destroyed and purged from the gut. The appendix effectively acts as a safe haven for reserve bacteria which can repopulate our gut once the immune system has beaten the illness away.

The research also says that the appendix plays a vital role in the way our immune system develops. Following birth, lymphoid tissue develops and accumulates in the organ which in turn helps B lymphocytes to mature and stimulates antibody production.

And that is not all; according to the researchers, the appendix also produces molecules which help transport lymphocytes to the locations in the body where they are most needed.

The researchers were at pains to point out that appendicitis is a very serious condition and that people should not try to hang onto their appendix if it is causing them trouble.

However, some of the evidence points to the fact that people without an appendix are more prone to certain illnesses. The appendix acts as a reserve for beneficial gut microflora which researchers say provides back up protection when their numbers are reduced by sickness.

Those whose appendix has already been removed are far more likely to suffer an intestinal inflammatory condition or colitis caused by Clostridium difficile bacteria. The illness can cause a number of nasty symptoms including severe abdominal cramps, fever and diarrhea. Clostridium difficile tends to be present if the body is lacking the normal amounts of gut flora. This might add further credence to the theory that the appendix is linked to maintaining the levels of healthy gut bacteria.

Appendix complications

Despite these newfound benefits, the appendix is still prone to developing appendicitis which causes it to become inflamed and which may lead to a rupture if it is not dealt with swiftly. The cause is not always known but may be a result of a blockage caused by a build-up of parasites, mucus or more often than not of fecal matter.

Appendicitis can be a very serious illness and should never be taken lightly. When it is left untreated, it can result in a condition called peritonitis which is a very serious and potentially life threatening infection. According to estimates several hundred people in the US die as a result of appendicitis each year while the figure is much higher in other parts of the world.

Symptoms of appendicitis include a serious pain in your lower right abdomen, nausea and fever. If you have these symptoms, it is very important to seek medical help as soon as you can.

Treatment normally means removal of the appendix but do not worry. In spite of this new research, the vast majority of people will recover very quickly and suffer no future complications.

(1) http://www.sciencedirect.com/science/article/pii/S002251930700416X