CBS Mutation & Low Sulfur Diet


CBS Mutation and Low Sulfur Diet:

As a clinician, I have learned that what is healthy for one individual can be poison for another.  When it comes to sulfur, most people NEED more of it and not less.  This is because sulfur based amino acids are foundational components to many enzymes including the powerful anti-oxidant enzyme glutathione.

When the body metabolizes sulfur compounds it produces ammonia as a byproduct.  Ammonia is toxic to the body but most individuals are able to easily excrete it through the urine. Unfortunately, some individuals have particular genetic mutations that do not allow them to effectively metabolize and eliminate ammonia.

Ammonia Production:

Ammonia is a normal product of protein metabolism in the body is generally excreted through our urine.  However, when we are unable to effectively excrete it, major health problems ensue.

Higher levels of ammonia are produced during times of stress as the body uses amino acids and breaks them down into glucose through a process called gluconeogenesis.  Higher amounts of stress will lead to elevations in ammonia.

The gut microbiome (full collection of microorganisms) metabolizes the amino acids into nitrogen compounds, which are used to repair cells.  Some of the species present in our microbiome also produce ammonia when they break down amino acids.  Some individuals have alterations in their gut microbiome to where ammonia producing bacteria are overpopulated.

Our microbiome produces almost 4 grams of ammonia each day in our intestines.  This ammonia is taken to the liver and is turned into urea where it is excreted in the urine.   When the body is producing excessive ammonia and/or when it is not filtering and excreting enough ammonia we can end up with very serious problems.

Elevated ammonia levels reduce the production of cellular ATP which is key for energy production.  This is why individuals with elevated ammonia experience fatigue, muscle weakness, nausea, vomiting, headaches, diarrhea, back pain and accelerated aging.

Ammonia is also extremely damaging to the brain and can lead too mood disturbances, insomnia, loss of coordination and dexterity, clumsiness, confusion and inability to concentrate.

Addressing the CBS Gene Mutation:

The cystathione beta synthase (CBS) enzyme helps make the conversion of homocysteine to cystathionine as part of the transsulfuration pathway (1).  Defects in this enzyme are upregulations in that the enzyme works too fast.   According to Nutrigenomic expert Dr Amy Yasko, the CBS gene mutation must be supported before addressing other genetic variants.

Individuals with a CBS mutation (elevated activity) often have high levels of taurine and ammonia and low cystathione and homocysteine (2,3).  This is due to the rapid conversion and if this is coupled with NOS mutations it can exacerbate ammonia issues.  High ammonia is extremely toxic and inflammatory to the body.

Individuals with a CBS mutation that slows activity have low ammonia and elevated cystathione and homocysteine.  Only individuals with high firing CBS enzyme activity end up with elevations in ammonia.  Individuals with low firing CBS enzyme activity have their own issues with homocysteinuria.

Stabilizing CBS and Lowering Ammonia:

Dr Yasko makes it very clear that stabilizing the CBS mutation and lowering ammonia levels must come before starting other methylation supplementation.  If one tries to support methylation without addressing CBS, the nutrients do not effectively generate glutathione and may negatively effect the entire cycle (4, 5, 6).

The CBS mutation leads to excess taurine, ammonia and sulfur groups that are released into toxic sulfites in the body.  If the individual is consuming large amounts of sulfur containing foods it can lead to more sulfites and increased stress and inflammation (2).

Dietary Restrictions to Stabilize CBS

These individuals must be on a low protein diet where protein makes up about 10% of total caloric intake.  For these individuals, I typically recommend a nutrition plan consisting of 70-80% fat, 10-20% carbohydrate and 10% protein.

Sulfur containing foods are extremely healthy for most individuals but not for those with major CBS mutation problems.  These individuals must limit sulfur intake by removing garlic, onions, cruciferous veggies, eggs, legumes, all protein-rich dairy.  They also must avoid normally great supplements like alpha lipoic acid, chlorella, spirulina, glutathione, MSM, DMSO and N-Acetyl Cysteine.

Detoxification strategies such as heavy metal chelators and Epsom salt baths should be avoided as well.   Other supplements to avoid will be L-methionine, L-cysteine, L-taurine, glucosamine, L-glycine, DMSO, SAMe, methylcobalamine, methyl-folate, Betaine, HCL and choline.

Methylation and MTHFR Defects presented by Benjamin Lynch, ND

Nutrition Plan to Reduce Ammonia:

It is also extremely important to have good drinking water filtration and shower filtration to avoid ammonia that may be in typical city municipalities.  A reverse osmosis filter will take the ammonia out of the water and you can add back trace minerals with a pinch of pink salt.

The nutrition plan should focus on full-fat coconut products, grass-fed butter/ghee and small amounts of grass-fed and pasture-raised meat.  Avocados are good and low-sulfur veggies such as romaine lettuce, celery, cucumbers, carrots and parsley will be very good.  Chia, sunflower, flax and pumpkin seeds along with macadamia nuts can be used in moderation.  Fatty portions of animal such as stock bones are typically well tolerated.

Small amounts of meat and fish can also be used but protein levels should be kept under 50 grams per day.  Extra-virgin olive oil can be used generously as can herbs like turmeric, ginger, oregano, basil, thyme, rosemary and cinnamon.  You can find the whole sulfur intolerance nutrition plan here

Detoxifying Ammonia:

The three major areas responsible for detoxifying ammonia are the liver, kidneys and intestines (7).  One major medical indicator of liver failure is high levels of ammonia in the bloodstream.  The liver normally receives ammonia from the intestines as it is metabolized from amino acids.

A healthy liver detoxifies ammonia and converts it into urea, which then goes to the kidneys and out through the urine.  When the liver is malfunctioning, the ammonia is unmetabolized and may enter into the bloodstream.

Liver health is dependent upon three sulfur based processes: Sulfation, Glucoronidation and Glutathione conjugation.   These three processes all depend upon sulfur compounds which makes liver function challenging for CBS mutations.   The best way to address this is with high dosages of buffered vitamin C w/bioflavonoids, dandelion and parsley.   These are low-sulfur and support the liver’s detoxification processes and glutathione recycling.

Increasing chlorophyll content is also very helpful as it neutralizes ammonia and carbon monoxide.  You can get liquid chlorophyll and add it to your water and you can juice high chlorophyll veggies such as wheat grass and barley grass which are more nutrient dense than chlorophyll alone.

Kidney Excretion:

The kidneys play an important role in filtering out urea and forming urine.  One of the biggest challenges for the kidneys is unstable blood sugar levels.  If blood sugar is imbalanced it will overwork the kidneys and reduce their filtering capacity.  Elevated blood sugar causes increased potassium excretion.  Potassium has a strong alkalizing effect and changes the pH of the urine.  This reduces the kidney’s ability to filter and flush ammonia from the system.

Elevations in ammonia also cause an increased urinary excretion of magnesium, calcium and phosphate.  It also disrupts normal glucose metabolism and can lead to instability in blood sugar.  So this is the tough part, unstable blood sugar promotes ammonia accumulation in the body and elevated ammonia disrupts blood sugar stability.

There are three key amino acids needed for the urea cycle and they function to protect against ammonia toxicity.  These include L-Arginine, L-Citrulline and L-Ornithine.  These are all important but L-Ornithine may be the most critical as it helps remove ammonia from the brain.    Taking dosages of 500 mg of L-Ornithine in the evening and 500 mg of L-Arginine in the morning can be very helpful to aid ammonia metabolism.

Eating celery and drinking celery juice is another helpful strategy to remove excess ammonia and provide good electrolyte balance in the body.

Intestinal Health:

Small amounts of ammonia are naturally produced as a byproduct of protein digestion.  When there is an overgrowth of ammonia producing microorganisms in the gut it can cause serious problems.

Taking some natural anti-microbial compounds such as oregano oil, caprylic acid, black walnut hulls, bearberry extract, grapefruit seed extract, Pau D arco, cat’s claw, slippery elm, etc. will help to reduce the quantity of the ammonia producing microorganisms.  Also, using apple cider vinegar, kombucha and coconut water kefir are great too.

Additional supplementation with probiotics and fermented, low-sulfur foods such as pickles, beet kvass and coconut milk kefir will help to reinnoculate the gut with good microorganism.  Restoring integrity to the gut will help to reduce ammonia build-up in the body and take stress of the liver and kidneys.

Yucca root is also effective for reducing ammonia generation in the intestines.  Cleansing agents such as bentonite clay and activated charcoal have an affinity for ammonia ions and help to pull these along with other endotoxic debris out of the body.


Protecting the Brain From Ammonia:

The brain is especially sensitive to ammonia levels and doesn’t have an effective way of buffering ammonia.  If ammonia levels are high in our blood stream and it is able to cross the blood brain barrier it can be especially dangerous.  Ammonia will cause massive inflammatory damage and destroy many brain cells.

L-glutamine is the most abundant amino acid in the body and plays an important role in stabilizing blood sugar and reducing ammonia levels. When ammonia levels raise the body uses more glutamine in order to reduce the ammonia.

Magnesium is also very important as it helps to stabilize the blood brain barrier.  When blood sugar is imbalanced it causes the body to use up more magnesium and leaves the brain vulnerable to ammonia toxicity.  Magnesium is also important for glutamine metabolism by activating glutamine synthetase, an enzyme that helps to remove ammonia from the cells.

Other supplements that can be helpful include molybdenum, manganese, acetyl-L-carnitine and zinc as excess sulfites may deplete these.


Avoiding Toxic Tap Water:

One of the major sources of ammonia is through drinking city water.  The city adds a mixture of chlorine and ammonia, also called Chloramine, as a sterilizing agent to prevent against infectious diseases being passed through the water systems.

This is a challenging toxin for simple carbon filters to remove and thus most people are ingesting high amounts of ammonia.  This is extremely hazardous and for those with a genetic susceptibility or poor detoxification systems can be life threatening.  This is why a good water filter is SO CRITICAL for a sulfur intolerant individual to get well.

Sources For This Article Include:

1. http://ghr.nlm.nih.gov/gene/CBS

2. http://www.ncbi.nlm.nih.gov/pubmed/?term=cbs+polymorphism+ammonia

3. http://resqua.com/702188759/what-does-a-cbs-gene-mutation-mean

4. http://www.dramyyasko.com/resources/autism-pathways-to-recovery/chapter-6/

5. http://geneticgenie.org/methylation-analysis-example/

6. http://metabolichealing.com/metabolic-gateways-cbs-gene-mutations-glutathione/

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