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The science of purging, or the purging of science?

It’s Thanksgiving in the U.S., one of my favorite holidays.  Thanksgiving habits get set down early in life, and the while I may find your lima bean casserole execrable, to you it’s just not Thanksgiving without it.

And speaking of excrement, you can expect to see adds encouraging you to “detox” from all of your holiday excesses.  Outside the field of substance abuse, what the hell is “detox” anyway?  “Detoxification” is apparently the pinnacle of modern health care, if you believe the dozens of adds on late-night TV.

For me to explain to you why even the very idea is laughable, I have to teach you a bit of human biochemistry—just a little, I promise. My scientific readers will find this grossly oversimplified, but hopefully they will forgive me.

Detox sounds so simple, but in fact, human biology is more complex and beautiful than is dreamt of in the quacks’ philosophies.

Your body is a complex biochemical machine, but not all that mysterious. Human biochemistry is a fascinating area of research, and has been for over a century.

In order to produce and use the energy that keeps us alive, the essential substances of life must be taken in or produced, utilized, and the byproducts of their metabolism removed. Among the substances essential to life are water, oxygen, lipids (fats), carbohydrates (starches and sugars), polypeptides (proteins), and nucleic acids (DNA and RNA).

There are other micro-nutrients that are essential to life, which early scientists named “vitamins”. Vitamins aid in the metabolism of the various substances listed above. They are required in very small amounts to be effective.

The intake, utilization, and production of these essential substances is the meat of biochemistry.  A large part of metabolism gives us the horribly toxic byproducts of carbon dioxide and water.  I like to think that the detox folks are speaking of something else, but who know.  When speaking of “toxin removal” a few organs in particular deserve mention.

Lungs

One of the most important byproducts of human energy metabolism is carbon dioxide (CO2). People think of the lungs as the “oxygen gatherers” of the body, but at least as important is their role in removing CO2 from the body. The kidneys may remove small amounts, but it really falls to the lungs. Failure to remove CO2 is one of the main reasons that a patient may end up on a ventilator, more so than lack of oxygen.

Kidneys

CO2 functions as an acid in the body, and the lungs and a blood buffering system keep the body’s pH closely regulated. Even small deviations of pH create a very, very sick person. The kidneys help remove various other acids produced by the body, and one of the effects of kidney failure is to be come “acidotic”. The kidneys also remove excess water from the body, as water is a main by product of metabolism. Water also serves as a solvent, or vehicle, to removing excess electrolytes and other toxic metabolic wastes, such as urea.

Liver

The liver is a giant factory of necessary substances, and also serves as an organ of “detoxification”. Once of the ways the liver does this is by taking toxic substances that are not soluble in water, and adding a molecule that allows them to dissolve in water and be excreted by the kidneys. The liver also produces bile, which eventually helps certain substances be excreted in the stool.  A common biliary target of detox quackery is the “gall stone flush“, which uses old-fashioned sleight-of-hand to make the pigeon think they have purged themselves of stones.  And “liver pills” are as old as advertising.

Colon

The colon is not so much a detoxifying organ as a waste removal and water reclamation unit. When a colon ruptures, it is not the toxins contained in the stool that makes someone sick, but the overwhelming infection due to colonic bacteria. These bacteria normally live peacefully, even benevolently, in the colon, but they are rather nasty if they reach the rest of the body.

People don’t like poo, and the colon is seen as “dirty”, but it is actually an efficient, complex hunk of machinery. Certain diseases can disrupt the machinery—certain infections (some caused by antibiotics), autoimmune diseases, trauma—but there is no inherently “toxic” condition in the colon. It’s just a “poop chute”, and does its job well.

Toxic states

When our own complex detoxification system breaks down, we become noticeably ill—not just “uneasy”, but very, very sick. Failure of the lungs to remove CO2 lands us on a ventilator. Liver failure, which is more complex than just toxin removal, leads to death without transplant. Kidney failure leads to uremia, acidosis, electrolyte imbalances, and water overload. As mentioned above, the colon really only hurts us if other diseases attack it and thereby compromise its integrity.

Acid-Base regulation
As mentioned above, acid-base balance is so tightly regulated, that even very small variations create a very ill patient.  Enzymes, which are really biologic catalysts, only function well in a narrow pH range.  Attempts to change your pH through diet are going to fail, as your lungs and kidneys will make up the difference—unless you do it  so drastically that you succeed, leading to illness and death.  Claims regarding pH and health are a bunch of hooey.

Detoxification

Detoxification refers to a host of interventions that supposedly rid your body of harmful toxins. This type of woo usually falls into a few specific categories, but since it isn’t guided by science, there are wide variations. The only common thread is that none of these ideas are based on any real understanding of biochemistry, and none have been successfully tested and shown to be effective.

  • Poo woo: Colon cleansing is a popular pastime. The only reason to completely empty a colon is so that a colonoscopist can see without being blinded by a shit storm, or so a surgeon can safely operate on the gut without worrying about soiling the abdominal cavity with colonic bacteria.
  • Chelation: Chelation is a very popular form of quackery. It has been purported to do almost every kind of good, and is especially popular among cranks who believe in the mercury-vaccine-autism hypothesis. It’s killed a few people, but that doesn’t stop the quacks.
  • Liver detox: another load of crap. See article.

The final myth, about which Orac knows more, is this “oxidation” business. Free radicals are oxidative compounds formed in our bodies. Some are waste products, some are used by the immune system to kill invaders—it’s rather complex. This complexity can be seen in the offers of woo-peddlers. Some try to sell you “anti-oxidants”, while others try to sell you oxygenated drinks or “hyperbaric oxygen“—they can’t seem to decide which is better— more oxygen or less oxygen. The truth is the human body pretty much takes care of this stuff, and more research is being done on the whole “free radical” issue. It’s not as simple as the quacks make it sound.

Except in the context of substance abuse treatment, the term “detoxification” is wholly unmedical, unscientific, and quasi-religious. Nearly everyone who offers it tacks on a Quack Miranda Warning. If you aren’t feeling well, medical science has much to offer—sometimes there are no easy answers, but they certainly won’t be found on late-night TV.

Posted in: Science and Medicine

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5 thoughts on “The science of purging, or the purging of science?

  1. Dilaceratus says:

    Fine article, but (as used in the opening paragraphs) the word execrable doesn’t have anything to do with excretion. It instead refers to the act of cursing.

    (Unless you were trying to say that lima bean casserole is itself another phrase for excrement. In which instance your case may have more merit.)

  2. overshoot says:

    Failure to remove CO2 is one of the main reasons that a patient may end up on a ventilator, more so than lack of oxygen.

    Thanks for the reminder. I wish CPR classes emphasized this, since respiratory cessation leads to cardiac arrest. There’s a reason that we do “Airway, Breathing, Circulation” instead of some other order.

    Be well, please enjoy the day with those you love.

  3. Fizzizist says:

    “Your body is a complex biochemical machine, but not all that mysterious. ” This is famous quote material right here. Good article I now know a little more about my body so thank you very much, and happy thanksgiving.

  4. Cultural Iconography says:

    Excellent article! You really have a talent for explaining things clearly and interestingly.

    I highly recommend you submit it to a few MSM outlets, to see if any of them are interested. Of course, given the stunning scientifically illiteracy of the MSM, and alas, the public itself, I doubt it.

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