inflammation

You are currently browsing articles tagged inflammation.

The thyroid-gut connection

July 29, 2010 in Thyroid Disorders | 2 comments

Hippocrates said: “All disease begins in the gut.” 2,500 years later we’re just beginning to understand how right he was. And, as I’ll explain in this article, hypothyroidism is no exception. Poor gut health can suppress thyroid function and trigger Hashimoto’s disease, and low thyroid function can lead to an inflamed and leaky gut – as illustrated in the following diagram:

thyroidgut

The gut-thyroid-immune connection

Have you ever considered the fact that the contents of the gut are outside the body? The gut is a hollow tube that passes from the mouth to the anus. Anything that goes in the mouth and isn’t digested will pass right out the other end. This is, in fact, one of the most important functions of the gut: to prevent foreign substances from entering the body.

Another important function of the gut is to host 70% of the immune tissue in the body. This portion of the immune system is collectively referred to as GALT, or gut-associated lymphoid tissue. The GALT comprises several types of lymphoid tissues that store immune cells, such as T & B lymphocytes, that carry out attacks and produce antibodies against antigens, molecules recognized by the immune system as potential threats.

Problems occur when either of these protective functions of the gut are compromised. When the intestinal barrier becomes permeable (i.e. “leaky gut syndrome”), large protein molecules escape into the bloodstream. Since these proteins don’t belong outside of the gut, the body mounts an immune response and attacks them. Studies show that these attacks play a role in the development of autoimmune diseases like Hashimoto’s.

We also know that thyroid hormones strongly influence the tight junctions in the stomach and small intestine. These tight junctions are closely associated areas of two cells whose membranes join together to form the impermeable barrier of the gut. T3 and T4 have been shown to protect gut mucosal lining from stress induced ulcer formation. In another study, endoscopic examination of gastric ulcers found low T3, low T4 and abnormal levels of reverse T3.

Likewise, thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH) both influence the development of the GALT. T4 prevents over-expression of intestinal intraepithelial lymphocytes (IEL), which in turn causes inflammation in the gut.

The gut-bacteria-thyroid connection

One little known role of the gut bacteria is to assist in converting inactive T4 into the active form of thyroid hormone, T3. About 20 percent of T4 is converted to T3 in the GI tract, in the forms of T3 sulfate (T3S) and triidothyroacetic acid (T3AC). The conversion of T3S and T3AC into active T3 requires an enzyme called intestinal sulfatase.

Where does intestinal sulfatase come from? You guessed it: healthy gut bacteria. Intestinal dysbiosis, an imbalance between pathogenic and beneficial bacteria in the gut, significantly reduces the conversion of T3S and T3AC to T3. This is one reason why people with poor gut function may have thyroid symptoms but normal lab results.

Inflammation in the gut also reduces T3 by raising cortisol. Cortisol decreases active T3 levels while increasing levels of inactive T3. 1

Studies have also shown that cell walls of intestinal bacteria, called lipopolysaccharides (LPS), negatively effect thyroid metabolism in several ways. LPS:

  • reduce thyroid hormone levels;
  • dull thyroid hormone receptor sites;
  • increase amounts of inactive T3;
  • decrease TSH; and
  • promote autoimmune thyroid disease (AITD).

Other gut-thyroid connections

Hypochlorhydria, or low stomach acid, increases intestinal permeability, inflammation and infection (for more on this, see my series on acid reflux & GERD). Studies have shown a strong association between atrophic body gastritis, a condition related to hypochlorhydria, and autoimmune thyroid disease.

Constipation can impair hormone clearance and cause elevations in estrogen, which in turn raises thyroid-binding globulin (TBG) levels and decreases the amount of free thyroid hormones available to the body. On the other hand, low thyroid function slows transit time, causing constipation and increasing inflammation, infections and malabsorption.

Finally, a sluggish gall bladder interferes with proper liver detoxification and prevents hormones from being cleared from the body, and hypothyroidism impairs GB function by reducing bile flow.

Healing the gut-thyroid axis

All of these connections make it clear that you can’t have a healthy gut without a healthy thyroid, and you can’t have a healthy thyroid without a healthy gut. To restore proper function of the gut-thyroid axis, both must be addressed simultaneously.

Healing the gut is a huge topic that can’t be covered adequately in a few short sentences. But I will say this: the first step is always to figure out what’s causing the gut dysfunction. As we’ve reviewed in this article, low thyroid is one possible cause, but often hypochlorhydria, infections, dysbiosis, food intolerances (especially gluten), stress and other factors play an even more significant role. The second step is to address these factors and remove any potential triggers. The third step is to restore the integrity of the gut barrier. My preferred approach for this last step is the GAPS diet.

The influence of thyroid hormones on the gut is one of many reasons why I recommend that people with persistently high TSH and low T4 and T3 take replacement hormones. Low thyroid hormones make it difficult to heal the gut, and an inflamed and leaky gut contributes to just about every disease there is, including hypothyroidism. Fixing the gut is often the first – and most important – step I take with my patients.

  1. Stockigt, JR and Baverman LE. Update on the Sick Euthyroid Syndrome. Diseases of the Thyroid. Humana Press, Totowa, NJ, 1997, pp.49-68 ↩

Tags: , , , , , ,

Three reasons why your thyroid medication isn’t working

July 1, 2010 in Thyroid Disorders | 24 comments

medicationIn the last post I explained that, for the vast majority of patients, hypothyroidism is an autoimmune disease. This isn’t just an academic distinction. It’s the reason both conventional and alternative treatments are so often ineffective.

In this post I’m going to show you why taking replacement thyroid hormones without addressing the underlying immune imbalance is doomed to fail.

The ultimate effect of hypothyroidism, whether it’s caused by iodine deficiency or autoimmunity, is to decrease the amount of thyroid hormone available to the body. The conventional approach is to simply replace these hormones with either synthetic or bio-identical forms.

On the surface it seems like a reasonable approach. Patient doesn’t have enough hormones? Give more hormones. Simple, right?

Not so much.

Once again the conventional approach falls short because it ignores the underlying cause of the problem. It’s like taking Advil when you’ve got a pebble stuck in your shoe. It might work for a little while, and might even be necessary to dull the pain. But you’d be a lot better off if you took the pebble out of your shoe. Right?

Let’s take a closer look at why thyroid hormones often don’t work, or stop working over time. The following diagram illustrates how autoimmunity affects thyroid metabolism:

hashimotos

Immune dysregulation is another term for autoimmune disease. We still don’t know exactly what causes it, but most researchers agree it’s a mixture of genetic susceptibility and environmental factors such as iodine (excess), infection, pregnancy, diet and intestinal permeability.

In autoimmune disease the body attacks itself. It does this the same way it attacks foreign invaders like bacteria and viruses: with T-cells, B-cells, natural killer cells, and cytotoxic T cells. The immune response also involves proteins called cytokines, chemical messengers that pass messages between cells.

This self-attack by the immune system increases inflammation. And inflammation has a profound effect on all aspects of thyroid metabolism and physiology.

First, inflammation suppresses the hypothalamus-pituitary-thyroid (HPT) axis. One study showed a single injection of the inflammatory cytokine TNF-alpha reduced blood levels of TSH, T3, free T4, free T3 and TRH for 5 days. This shows inflammation disrupts the production and regulatory mechanisms of thyroid hormones. Thyroid medication will increase the levels of T4 (and possibly T3), but it doesn’t address the other effects of HPT axis suppression.

Second, inflammation decreases both the number and sensitivity of thyroid hormone receptors. If there aren’t enough receptors, or they aren’t sensitive enough, it doesn’t matter how much thyroid medication we take. The cells won’t be able to use it. It’s like when my grandpa used to turn down his hearing aids while he was watching the football game. It didn’t matter how much my grandma yelled at him – he couldn’t hear a word she said.

Third, inflammation decreases the conversion of T4 to T3. T4 is the inactive form of thyroid hormone. The body has to convert it to the active T3 form before it can be used. Most synthetic hormone medications on the market are T4. If you give a T4 medication (like Synthroid, Levoxyl, Unithroid, etc.) to someone with inflammation, it’s not going to work because they can’t convert the T4 to T3.

Patients who don’t convert T4 to T3 well do better on bio-identical hormones like Armour, because it contains both T4 and T3 (in a 4.22:1 ratio).

Inflammation disrupts thyroid metabolism in several other ways, but I think these three examples make the point.

Now let’s review.

Inflammation causes HPT axis disruption, decreased receptor function, and decreased conversion of T4 to T3. Thyroid medication only increases the levels of thyroid hormone (usually T4) in the blood. No matter how much we take, it’s not going to restore HPT axis coordination, improve receptor function, or increase conversion of T4 to T3.

The only way to do that is to address the problem at its root by regulating the immune system and decreasing inflammation. Unfortunately, this is rarely done in either conventional or alternative treatment of thyroid disorders.

Before I sign off, I just want to make one thing clear. I’m not saying thyroid medication isn’t necessary or useful. In fact, I think it’s an important part of treating Hashimoto’s – especially when TSH is consistently elevated and T4 and T3 are consistently low. My point is thyroid medication is only one piece of the puzzle, and it won’t be effective on its own unless the autoimmunity and inflammation are addressed.

If thyroid medication is the fantasy magic bullet of conventional medicine, iodine is the equivalent in alternative medicine. In the next post I’m going to explain why supplemental iodine may cause more harm than good in Hashimoto’s patients.

Tags: , , , , , , ,

Chinese Medicine Demystified (Part IV): How Acupuncture Works

March 11, 2010 in Myths & Truths | 24 comments

person receiving acupunctureNote: This is the fourth article in an ongoing series. Make sure to read the previous articles before reading this one, and check out the next articles in the series afterwards.

In this post we’re going to explore how acupuncture works from a western scientific perspective. As I’ve argued in the previous articles, there is no disagreement between the fundamental anatomical and physiological concepts of western and Chinese medicine. However, as methods of scientific inquiry have progressed, the mechanisms of acupuncture are beginning to be more clearly understood.

Acupuncture effects every major system of the body, including the cardiac, gastrointestinal, circulatory, cerebral, genitourinary, endocrine and immune systems. It would take an entire book to describe all of the mechanisms involved, and in fact there is such a book for those who are interested in that level of detail. In this post my purpose is to summarize that research in a way that’s easy for lay people to understand, while providing links to more technical resources for medical professionals and others that might be interested.

Broadly speaking, acupuncture has three primary effects:

  1. It relieves pain.
  2. It reduces inflammation.
  3. It restores homeostasis.

Homeostasis refers to the body’s ability to regulate its environment and maintain internal balance. All diseases involve a disturbance of homeostasis, and nearly all diseases involve some degree of pain and inflammation. In fact, research over the last several decades suggests that many serious conditions like heart disease previously thought to have other causes are in fact primarily caused by chronic inflammation. If we understand that most diseases are characterized by pain, inflammation and disturbance of homeostasis, we begin to understand why acupuncture can be effective for so many conditions.

Several modes of action have been identified for acupuncture, which I’ll discuss below. The mechanisms can get quite complex. But ultimately acupuncture is a remarkably simple technique that depends entirely upon one thing: the stimulation of the peripheral nervous system. It’s important to point out that when nerves supplying acupoints are cut or blocked there is no acupuncture effect.

A large body of evidence indicates that acupoints, or “superficial nodes” as they are more accurately translated, have abundant supply of nerves. According to Chen Shaozong, “For 95% of all points in the range of 1.0 cm around a point, there exist nerve trunks or rather large nerve branches.” 1

The following is a list of mechanisms that have been identified so far:

  • Acupuncture promotes blood flow. This is significant because everything the body needs to heal is in the blood, including oxygen, nutrients we absorb from food, immune substances, hormones, analgesics (painkillers) and anti-inflammatories. Restoring proper blood flow is vital to promoting and maintaining health. For example if blood flow is diminished by as little as 3% in the breast area cancer may develop. Blood flow decreases as we age and can be impacted by trauma, injuries and certain diseases. Acupuncture has been shown to increase blood flow and vasodilation in several regions of the body.
  • Acupuncture stimulates the body’s built-in healing mechanisms. Acupuncture creates “micro traumas” that stimulate the body’s ability to spontaneously heal injuries to the tissue through nervous, immune and endocrine system activation. As the body heals the micro traumas induced by acupuncture, it also heals any surrounding tissue damage left over from old injuries.
  • Acupuncture releases natural painkillers. Inserting a needle sends a signal through the nervous system to the brain, where chemicals such as endorphins, norepinephrine and enkephalin are released. Some of these substances are 10-200 times more potent than morphine!
  • Acupuncture reduces both the intensity and perception of chronic pain. It does this through a process called “descending control normalization”, which involves the serotonergic nervous system. 2 I will explain this process in further detail in the next post.
  • Acupuncture relaxes shortened muscles. This in turn releases pressure on joint structures and nerves, and promotes blood flow.
  • Acupuncture reduces stress. This is perhaps the most important systemic effect of acupuncture. Recent research suggests that acupuncture stimulates the release of oxytocin, a hormone and signaling substance that regulates the parasympathetic nervous system. You’ve probably heard of the “fight-or-flight” response that is governed by the sympathetic nervous system. The parasympathetic nervous system has been called the “rest-and-digest” or “calm-and-connect” system, and in many ways is the opposite of the sympathetic system. Recent research has implicated impaired parasympathetic function in a wide range of autoimmune diseases, including arthritis, lupus, rheumatoid arthritis and inflammatory bowel disease.

Several other mechanisms have been identified, but the ones I’ve listed above are the most relevant and clearly understood.

Some purists object to acupuncture being described in biomedical terms. They claim that such descriptions are “reductionistic” and narrow-minded, and don’t take into account those aspects of acupuncture that we may not yet understand.

Others who are still committed to the “energy meridian” model are opposed to the biomedical descriptions because, in their eyes, such scientific inquiry “takes the magic” out of acupuncture.

While I agree that there we don’t yet fully understand how acupuncture works, I think it’s vital that practitioners of acupuncture are able to explain what we do know about it from a biomedical perspective to their patients and colleagues in the medical profession. As practitioners we have a moral obligation to provide each patient with the latest medical understanding available in terms they can understand and relate to. Doing this will improve patient outcomes and open the door for acupuncture to be integrated into the healthcare system, which is needed now more than ever.

I would also suggest that explaining the mechanisms of acupuncture in scientific terms should not in any way lessen our appreciation of its uniqueness. The fact that inserting fine needles into the skin can have such a broad range of powerful effects is just as remarkable when those effects are explained in terms of the nervous system as when they are explained in terms of “energy” and “meridians”. When you consider that the Chinese made these discoveries hundreds of years before the birth of Christ, acupuncture is even more impressive.

What’s more, as others have pointed out, acupuncture is inherently holistic even without the “energy meridian” theory because it restores internal homeostasis through the simple act of piercing the skin with a needle.

In the next article I’ll explain the latest theory on how acupuncture relieves pain in more detail. Stay tuned, and as always, I welcome your comments!

  1. Shaozong, C. Modern acupuncture theory and its clinical application. (Chapter 5 The Morphologic Relationship between Points and Nerves). International Journal of Clinical Acupuncture. 2001;121(2):149-158 ↩
  2. Dung HC. Anatomical features contributing to the formation of acupuncture points. American Journal of Acupuncture. 1984;12:139-143 ↩

Tags: , , , , , , ,

Inflammation worsens danger of heart disease

January 22, 2009 in Heart Disease | 13 comments

inflammationA recent study published in the American Journal of Pathology adds to the already considerable body of evidence which suggests that inflammation is a primary cause of heart attacks and strokes.

In an article I wrote last year, Preventing Heart Disease Without Drugs, I reviewed the current scientific understanding of what causes heart disease. If you’ve been following this blog, you know that inflammation and oxidative damage – not saturated fat and cholesterol – are the primary causes of heart disease.

I wrote:

Inflammation is the body’s response to noxious substances. Those substances can be foreign, like bacteria, or found within our body, as in autoimmune diseases like rheumatoid arthritis. In the case of heart disease, inflammatory reactions within atherosclerotic plaques can induce clot formation.

When the lining of the artery is damaged, white blood cells flock to the site, resulting in inflammation. Inflammation not only further damages the artery walls, leaving them stiffer and more prone to plaque buildup, but it also makes any plaque that’s already there more fragile and more likely to burst.

Oxidative damage is a natural process of energy production and storage in the body. Oxidation produces free radicals, which are molecules missing an electron in their outer shell. Highly unstable and reactive, these molecules “attack” other molecules attempting to “steal” electrons from their outer shells in order to gain stability. Free radicals damage other cells and DNA, creating more free radicals in the process and a chain reaction of oxidative damage.

Normally oxidation is kept in check, but when oxidative stress is high or the body’s level of antioxidants is low, oxidative damage occurs. Oxidative damage is strongly correlated to heart disease. Studies have shown that oxidated LDL cholesterol is 8x greater stronger a risk factor for heart disease than normal LDL.

The data from this study provide further support for the “oxidative response to inflammation” hypothesis described above. The researchers found that inflammation leads to a reduction of mature collagen in atherosclerotic plaques, leading to thinner caps that are more likely to rupture. This is important because other studies have shown that it is not atherosclerosis alone, but the rupture of the atherosclerotic plaques, that causes heart attacks and strokes.

It follows, then, that if we want to prevent heart disease we need to do everything we can to minimize inflammation and oxidative damage.

Top four causes of oxidative damage & inflammation

  1. Stress
  2. Smoking
  3. Poor nutrition
  4. Physical inactivity

By focusing on reducing or completely eliminating, when possible, the factors in our life that contribute to oxidative stress and inflammation, we can drastically lower our risk for heart disease.

For more in-depth information about each of these factors and how to minimize your risk of heart disease without drugs, please refer to Preventing Heart Disease Without Drugs.

Tags: , , , ,

Bad Behavior has blocked 376 access attempts in the last 7 days.

Better Tag Cloud