Diet & Digestion

From the standpoint of consumption, it is not difficult to achieve the recommended daily intake of copper in even a modestly “healthy” diet.  For adults, the RDA is considered to be 900mcg.  Considering the RDA, and that a fairly healthy total range for most people falls somewhere between 1mg-3mg per day, it is not difficult to achieve this dose.  Consider also that many supplements which contain copper typically provide 500mcg to 2mg. According to the NIH, the average human diet provides approximately 1100mcg - 1400mcg / day for women and men respectively.  In the West, and especially in India, that daily intake is higher.   Thus, even though the RDA is merely a baseline and some people may certainly do better with higher dietary intakes of copper, a true population-wide deficiency of dietary copper intake would not seem to be as pressing a concern as is what happens when excess copper is allowed to accumulate. 

Considering the important role of zinc and metallothionein in helping regulate copper and prevent excess copper absorption, along with the importance of bile in helping with excess copper excretion, we can see how certain dietary choices can lead one to greater risk of copper accumulating and/or developing copper toxicity.  The problem is not so much about higher copper intake through diet, it’s more about how the body is able to regulate the copper consumed.  

For this, we can begin by looking at the plant-based diet.  It's important that the following discussion is not taken as a knock on the virtues or benefits (at least short term) of veganism / vegetarianism.  Copper toxicity can affect anyone, meat eaters as well. This section is therefore not to dissuade anyone from the plant-based diet, but rather to empower the reader with information typically not discussed so that, regardless of dietary choices, one can take proactive steps as needed in order to protect and optimize health, and in some cases, recover faster.

The vegetarian diet, and even more so the vegan diet, does generally put one at higher risk of accumulating excess copper.  However, how long one’s been following a strict plant-based diet, in combination with the strength of one's detox pathways, genetic factors such as retinol conversion via the BCMO1 gene, stressors in life, and whether other sources of copper (such as the birth control pill or IUD) are also contributing – these factors all add up and, in the end, determine how affected one might be by their diet. We cannot paint everyone with the same paintbrush.  What one person tolerates the next person may not.  However, through HTMA data, we see the copper toxic pattern in a majority of long-term vegans/vegetarians.   Why is this?   

Well, for one, consider that retinol is required to lock the copper ion onto the ceruloplasmin transport protein.  Without retinol, copper tends to remain unbound and bio-unavailable, even as it accumulates.  The plant-based eater has to rely primarily on their body’s natural conversion of beta-carotene to retinol. For some people, this conversion is efficient.  However, for roughly half the population who have a BCMO1 genetic variant, this conversion to retinol is very poor… leading to an inherent retinol deficiency and, thus, potential issues with copper.

Secondly, zinc is very important for metallothionein (MT) synthesis.  One of MTs vital roles is binding to copper to support utilization and/or for removal and excretion. Without adequately absorbed dietary zinc, MT synthesis can be impaired, further allowing copper to build up. 

Phytates, common in plant foods, further compound the problem by interfering with zinc absorption. The copper-zinc ratio in plant foods is already high to begin with, and the phytates (and oxalates too, for that matter) just make it worse. Phytates significantly impair zinc absorption.  Without adequate 'high-absorption' zinc,  the individual  further lacks the ability to properly retain potassium.  Adequate potassium and especially zinc are necessary for hydrochloric acid secretion in the stomach - a deficiency of which can then further reduce nutrient assimilation and may also lead to developing a distaste for animal protein because it becomes harder to digest.  Eating meat then just doesn’t “feel as good”.   This mineral imbalance also contributes to a slowing of metabolism which further makes higher fat foods (ie: some meat cuts) more difficult to digest. The answer is not to simply eat more potassium, but rather to help the body make it usable by strengthening the adrenals, metabolism, and supporting stomach acid.  Otherwise, the vegetarian will continue to crave stimulants such as chocolate (high in sugar, copper, and oxalic acid) or running/jogging (which temporarily whips up the adrenal glands) making the person feel temporarily 'more alive'...all the while depleting energy reserves further and allowing copper to rise.

Another key deficiency in the vegan is sulfur, and the sulfur-containing amino acid taurine.  Taurine is an amino acid found in good supply in meat, and to a small extent in seaweed, but it is not found in vegetables grown on land.  Taurine is essential for the production of bile.   Bile is the primary method by which excess copper is removed from the body.  Sulfur, in general, is essential for liver detoxification and the removal of heavy metals from the body.  Though sulfur itself can certainly be found  in some  vegetables, it is in the most usable form in meat. The vegan, therefore, is also predisposed to not only a possible sulfur deficiency, but also a taurine deficiency, further impairing their ability to detox copper and other toxins.

Looking at how diet can contribute to copper toxicity from a different angle, it’s not as simple as assuming milligrams consumed has a straight correlation with toxicity.   It absolutely does not.  In fact, a person can have a high copper diet and not necessarily develop excess accumulation. A key reason for this is that, as dietary consumption increases, the absorption percentage of that copper decreases substantially, in effect protecting the body against toxicity or overload.  This is why the ability to consume a high copper diet has very little bearing on the development of copper toxicity. The body’s ability to regulate copper plays a much bigger role than intake alone.  

"The amount [of copper] absorbed increases as the amount in the diet increases, but absorption is much more efficient and a higher percentage is absorbed when intake is low. Thus, a 10-fold increase in dietary copper results in only twice as much copper absorbed."... 
…"The regulation of excretion appears to be more important than regulation of absorption in determining

copper retention"[3]

Copper toxic individuals very often will also have gut concerns, including candida and yeast, low HCl, poor nutrient absorption, gluten sensitivity, even leaky gut. One of copper's roles is that of an anti-fungal, and when in balance, helps to control fungi and yeast / candida in the gut.  However, with toxic levels of copper, much of this copper is in a bio-unavailable form stored in tissues, and is not serving it's role in controlling the candida / yeast, or other parasites. This, along with the anaerobic GI environment that's created, allows candida, fungi, yeast, parasites and bacteria to flourish. 

Indeed, many women experience yeast and candida issues when going on a copper IUD, yet the standard physician response to such concerns is that there is no connection.  However, a basic understanding of these mineral roles provides that connection, while even this study [5] indeed shows the increased risk of candida when on the copper IUD.

Meanwhile, as mentioned above, copper toxicity (by way of lowering zinc) also reduces hydrochloric acid production. When hydrochloric acid (HCl) is low, the healthy gut flora are weakened (and zinc is lowered further - a vicious cycle).  HCl helps kill off pathogens and is required for the absorption of nutrients such as calcium, iron, and various vitamins. Reduced digestive enzyme production occurs and the intestine becomes overly alkaline, giving a nice home to pathogenic bacteria. Copper toxicity leads to low HCl by way of slowing metabolism and reducing sodium and potassium levels, two minerals which are required in the production of HCl. The destruction of gut function and the collapse of one's metabolism are hallmarks of copper toxicity.

Long term copper-induced zinc deficiency will increase the permeability of the gut lining, contributing to leaky gut and food intolerances.  "Research has shown that both metallothionein and zinc play powerful roles in preventing and restoring the damage in the gut barrier. Damage to the intestinal barrier can lead to serious conditions, such as leaky gut, colitis and Crohn's Disease" [6].  We already know that copper lowers zinc, and zinc is important for metallothionein synthesis.  For the vegan / vegetarian, they do require extra zinc supplementation.  However, that alone may not be enough.  This is because, when the body is under stress or suffering from adrenal weakness, the zinc level can drop further even when supplementing - allowing copper to accumulate further.  A whole body / endocrine system approach is required to understand which supplements (and in what amounts) are optimal.