What Impairs Detoxification

You’ve learned so far that the sheer volume of chemicals we’re exposed to everyday is so great that it threatens to overload our detoxification systems. Exposure to toxins comes from two main sources: the environment (external toxins), and the gut (breakdown products of our metabolism, or internal toxins). Both can overload endogenous detoxification mechanisms. In addition, our genetics can play a role in our ability to handle these toxins in a safe manner. Let’s dig into the things that impair our detox processes.

External Toxins

The external toxins include chemical toxins and heavy metals from the environment.

  • The heavy metals that cause the most ill health are lead, mercury, cadmium, arsenic, nickel, and aluminum.
  • Chemical toxins include volatile organic compounds (VOCs), solvents (cleaning materials, formaldehyde, toluene, benzene), medications, alcohol, pesticides, herbicides, and food additives.
  • Infections (hepatitis C virus) and mold toxins (sick building syndrome) are other common sources of toxins.
  • Our modern refined diet can be considered toxic because it places an extra burden on detoxification systems through excessive consumption of sugar, high-fructose corn syrup (the two most important causes of elevated liver function tests), trans fatty acids, alcohol, caffeine, aspartame, foods made with genetically modified organisms (GMOs), and the various plastics, pathogens, hormones, and antibiotics found in our food supply.

Internal Toxins

Internal toxins include microbial compounds (from bacteria, yeast, or other organisms), and the breakdown products of normal protein metabolism.

  • Bacteria and yeast in the gut produce waste products, metabolic by-products and cellular debris that can interfere with many body functions and lead to increased inflammation and oxidative stress. These include endotoxins, toxic amines, toxic derivatives of bile, and various carcinogenic substances such as putrescine and cadaverine.
  • Lastly, by-products of normal protein metabolism, including urea and ammonia, require detoxification.


Genetics plays a role in our detoxification powers. Each of us has a unique ability to detoxify chemicals that we are exposed to depending on our individual genetic makeup.

Epigenetics, or the way our environment can switch on and off our genetic coding, can also make a difference in the way our body handles environmental toxins. Meaning, we can influence our ability by our lifestyle nd the foods we eat!

-MTFHR ( methylenetetrahydrofolate reductase) gene. You may have heard of this gene as being important for healthy Phase II detoxification. In fact, about 40% of people’s MTFHR gene is deactivated, or switched OFF, making it harder for them to detoxify their bodies. This gene switch is called a single nucleotide polymorphism (SNP) and is generally nothing to worry about, but may explain why some people have a harder time processing all the environmental toxins we are exposed to on a daily basis.

MTHFR is involved in a series of chemical reactions necessary for your body to properly use folate (vitamin B9) and Vitamin B12; in addition, it transforms a by-product of this process, homocysteine into the amino acid methionine. Methionine is an important building block in protein formation and required for the formation of S-adenosylmethionine (SAM-E), which is a universal methyl donor for almost 100 different substrates, including DNA, RNA, hormones, proteins, and lipids. What’s a methyl donor? It’s a carrier that contributes a methyl group (unromantically, a carbon atom attached to three hydrogen atoms), to a biological reaction in your body.

While there are at least 40 variations in the MTHFR genes, the two that at this time we know carry the most significance for human health and potential disease are the MTHFR genes known as A1298C and C677T. Because we have one copy of each from each of our parents, we can have one or two variations in either. One or even two changes in A1298C usually doesn’t usually lead to any health or medical consequences, though it merits awareness, while changes in C677T can, with two changes presenting the greatest likelihood of potential risk. Emphasis on the word potential – which I’ll come back to shortly.

Should you get testing? Conventional testing is readily available for the MTHFR SNPs themselves, and also for plasma homocysteine, B12, and folate levels. Any licensed provider can order these for you – though they are not necessarily all covered by insurance. Independent labs such as Genova and Doctor’s Data also offer these labs. To read more about what to do if you have the SNP, elevated homocysteine, or low B12, click here.

Remember, regardless of your MTHFR status, we all need to be mindful of supporting our elimination and detoxification pathways, avoiding the toxin exposures within our control in our diets, households, and body products, and leading healthful, mindful lives. Adding in a multivitamin with methylfolate, or supplementing a modest amount daily, is a safe and appropriate strategy even if you’re unable to get any testing and want to maximize your health protection.

-COMT (catechol-O-methyltransferase) is another enzyme and a common SNP to test for in functional medicine. It is attributed to poor detoxification particularly to things like caffeine, cocaine, and stress hormones like neurochemicals like dopamine, epinephrine, and norepinephrine. We typically associate these with a higher level of anxiety and low caffeine tolerance.

-Glutathione pathway is very important when it comes to detoxing the environmental toxins like solvents, herbicides, pesticides, fungicides, and heavy metals. Most people are deficient in glutathione because we are so bombarded with these chemicals in our environment. Furthermore, Tylenol causes us to use up a lot of glutathione in it’s detoxification process and is the leading cause of liver damage in the United States.

-SOD (superoxide dismutase) protects our cell membranes, DNA,  and mitochondria against oxidative stress and damage from free radicals.

Next we will discuss how you can influence and optimize your own body's detoxification processes.