Sulfur is the third most abundant mineral element in the body. It is critical for life and essential for optimal health.

Most, if not all, of our sulfur comes from food. In order to be utilised by the body, it needs to be converted to organic sulfate (SO4). This conversion happens for the most part in the brush border of the GI tract or in the liver.

I'm sure you're wondering... if it's so important for health... why do people become intolerant to it?

It's all about the ability to convert dietary sulfur to the form that our body can utilise to perform many important functions, which is organic sulfate (SO4). Some people have issues with this conversion, which means that although there might be plenty (or even too much) sulfur in the diet, it is not converted to the form that the body needs.

If this conversion is not working, not only will you be deficient in sulfate (see the many roles of sulfate below), but there are two main by-products that can be produced instead that can cause many health issues, hydrogen sulphide (H2S) and sulphite (SO3).

Hydrogen Sulphide (H2S) is a gasotransmitter, so it can easily access all cells in the body. It has a positive role in the body at a low/ controlled concentration. However, when level increases, it can have numerous negative effects, such as:

• Causing inflammation in the bowel wall (shown to contribute to inflammatory bowel disease such as ulcerative colitis, but also IBS).
• Impairment in learning, memory and reaction time.
• Impairment in blood sugar regulation (via death of insulin producing beta cells in pancreas).
• Possible implication in some cancers, mainly colon and ovarian.
• It relaxes blood vessels, so it lowers blood pressure. At high concentration, it can cause orthostatic hypotension, with dizziness upon standing.

Sulphite (SO3), such as the preservative in wine (more on sources of sulfites below), can also be produced as a by-product of sulfur metabolism. When in excess, it activates the sympathetic nervous system (fight or flight), causing anxiety. It also causes headaches, fatigue and brain fog for many people. Reacting negatively to the preservative in wine is an indication that you might have an issue with sulfur/sulfites.

SOURCES OF SULFUR

Diet: Most of our sulfur comes from diet. In fact, a lot of the foods that we consider very healthy are very high in sulfur, such as garlic, onions, cruciferous vegetables, dark leafy greens (kale, spinach) and eggs. Meat and dairy are also high in sulfur in the form of cysteine and methionine.

Sulfites (SO3): the preservative used in wine, dried fruits and other foods.

Mucus (sulfomucin): The mucus in our gut lining contains sulfur. This is important as it can be used as a source of food for sulfur reducing bacteria (more on that below).

Sulfur containing supplements: ALA, MSM, Taurine, NAC and most 'detox' supplements including milk thistle. If you've ever reacted negatively to those supplements, or when doing a detox protocol, it could be an indication that you have a sulfur intolerance . Many people think they are having a detox reaction, when in fact it's a negative reaction to the sulfur in the supplement.

Bile acids: Taurine, a sulfur containing amino-acid, is one of the building blocks of bile.

SOURCES OF SULFITES IN FOODS

Apart from being produced as a by-product of sulfur metabolism (when things go wrong), sulfites are frequently used as a food preservative and/or enhancer and its uses don’t stop with dried fruits and wines.

Some people can be extremely sensitive to even tiny amounts of sulfites… so it's worth taking a look at where sulfites can be found.

Sulfites slow down the browning (or discolouration) of foods. Think of a freshly cut apple. An organic apple will go brown within minutes after being cut. But an apple treated with sulfites will look perfectly white and fresh for hours - even days! I don’t know about you, but this just doesn’t seem ‘right’. You can check to see if a dried apricot is sulfite free simply by observing its colour. If it’s brown, it’s sulfite free. If it’s bright orange, it’s probably been treated with sulfites.

Sulfites can be listed on food labels, but can also remain undeclared and be hidden in many packaged foods. Sulfites do not need to be declared if they have been used as a part of food processing. This means that sulfites can even be found in foods labelled "preservative free". This can be a huge problem for people who suffer with severe sulfite sensitivities – especially for those who don’t even know they’re sensitive and have struggled with debilitating health issues for years without knowing why.

Sulfites can't be used in organic foods in Australia. Therefore, if you want to avoid sulfites in packaged foods, buy Australian Certified Organic (ACO). However, this may not the case in other countries.

A note on Organic Wines:

Even organic wines contain sulfites. However, there is less sulfur dioxide (220) used in organic and biodynamic wines. The level of sulphites in organic wines must be lower than their conventional equivalents. Certification typically allows 50 per cent of what can be used under conventional standards. There tends to be higher levels of sulfur dioxide added to white wines as they are more susceptible to oxidation, whereas the tannins in red wines act as a natural preservative. To complicate things even further, sulfur dioxide (220) can also be produced naturally by yeasts during the fermentation process. So, while buying a preservative free wine may help, it could still be a problem for some people. Preservative free basically means that no sulfites have been physically added to the product.

Sulfites come in various forms including:

• 220 Sulfur Dioxide
• 221 Sodium Sulfite
• 222 Sodium Bisulfite
• 223 Sodium Metabisulfite
• 224 Potassium Metabisulfite
• 225 Potassium Sulfite
• 228 Potassium Bisulfite

These sulfites are typically found in the following foods:

• Most dried fruits, including dried and shredded coconut (& therefore coconut milk/cream).
• Corn/maize starch/flour, potato starch/flour, and cassava/tapioca flour. As you can see by looking at these ingredients, gluten free foods can contribute heavily to sulfite overload.
• Thickeners and modified starches are also a hidden source of sulfites. Thickeners can be found in yogurts, ice cream, sauces, gravies, processed cheeses etc.
• Corn syrup, glucose syrup and caramel colour can also contain hidden sulfites.
• Bottled lemon juice.
• Cordials and other drink mixers.
• Potato chips/crisps and frozen potatoes (fries).
• Sausages, salami, hamburger patties and luncheon meats.
• Supermarket meats can be preserved with sulfites, especially mince/ground meats to prevent it from going brown.
• Prawns/shrimp are often treated with sulfites on the boat.
• Sulfites are used to preserve many bottled waters and can even be found in tap water, due to farming runoffs.

As you can see, sulfites can be found in many foods that you may consume on a daily basis. This means it can take years to finally realise that sulfites have been contributing to your health issues, as they are so hard to avoid. If you have health issues that are not improving with any other dietary intervention, you might be sensitive to sulfites and complete avoidance could lead to dramatic health improvements. We recommend avoiding all of the above to see if you feel better.

It's important to understand that you can still react to less than the ‘10 parts per million’ (USA), or ‘10mg per kilo’ (AUS) that is legally allowed in foods. Always read food labels, but be aware that there are many loopholes that allow manufacturers to put sulfites in your food without declaring it (even in organic foods in some countries).

Sadly, sulfites are used in such a wide range of industries because nearly everything requires a long shelf life.

Sulfites are even used to prevent skincare products like moisturisers from spoiling. Sodium Sulfite and Sodium Metabisulfite (& other forms of sulfites) are used in hair colour, facial cleansers and masks, facial moisturisers, anti-aging moisturisers, sunless tanning products and sunscreen. Remember that what you put on your skin gets directly absorbed into your system. This is why we recommend using organic skincare products as much as possible.

ROLES OF SULFATE IN THE BODY

As mentioned above, we need sulfate (in the form of organic/activated sulfate) for many crucial roles in the body. Remember that we need the sulfur in our diet to be converted to organic sulfate before it can perform the important functions described below.

Protein’s Building Blocks

2 sulfur amino-acid, cysteine and methionine, are used to build pretty much every protein in our body.

Connective Tissues

Connective tissues (such as ligaments and tendons, but also blood vessels, skin, etc) contain large amount of sulfate. Heparan sulfate supplies the sulfate needed by glucosamine and chondroitin to build strong connective tissues. Heparan sulfate, when combined with other sugars and proteins, forms glycosaminoglycans, or GAGS, and proteoglycans.

Without sulfate, our connective tissues lose it’s integrity, leading to ruptures, tears and other problems. A tendency to have tendon issues (tendinopathy) or very tight tendons can indicate a sulfate deficiency.

Detoxification

Sulfate is needed in phase 2 detoxification pathways in the liver called sulfation (more on that below).

Antioxidant

Many common antioxidants contain sulfate, such as alpha lipoic acid (ALA), glutathione and MSM.

Immune Function

Acute and chronic infection and inflammation raises the demand for sulfate dramatically in order to build the various molecules needed. Hence, chronic infection/inflammation would deplete sulfate.

Hormones and Neurotransmitters

Sulfate attaches to many hormones and other compounds in the body, acting as a shuttle for these molecules to be transported throughout the body. The hormones are generally considered to be inactive when sulfate is attached to it. Once it has been brought safely inside the target cells, enzymes remove the sulfate from the hormone and put it to any of several uses inside the cell. The hormone also becomes active in this process and can be put to use as well.

Sulfate is also needed to inactivate and remove catecholamines, such as dopamine, epinephrine, norepinephrine as well as exogenous phenolic compounds in certain foods (salicylates, histamine, etc).

This inability to breakdown catecholamines and dopamine can greatly affect stress and mood regulation.

Digestion and Gut Integrity

Not having enough sulfate can really interfere with your digestive function.

Sulfate is needed for the production of bile (hence fat digestion), via taurine, a sulfur containing amino-acid.

You also need it for pancreatic enzymes.

Sulfation increases the resistance to pathogenic bacteria. In fact, the way that H.Pylori colonises is by desulfating the gastric mucins in the stomach, and that allows them to colonise.

Unsulfated glycosaminoglycans in the gut lining will cause the gut to be leaky. In other words, low sulfate can lead to leaky gut.

Blood Viscosity

This is very complex, but let’s just say that sulfate regulates the viscosity of our blood.

HOW CAN WE BECOME SULFUR INTOLERANT

• Too much sulfur in the diet. We used to eat high sulfur foods seasonally, but nowadays it's become very popular to consume very high amount of sulfur-rich foods, such as garlic, onions, spinach, kale, etc.
• Glyphosate exposure (round-up), which interferes with the conversion of sulfur to sulfate in many ways.
• Heavy metals (aluminum, mercury, cadmium) exposure is a huge contributor to sulfur intolerance.
• Nutrient issues, mainly iron, B6, B12, Molybdenum and COQ10.
• Genetic (see more below on genes that can affect sulfur metabolism).

SYMPTOMS OF SULFUR INTOLERANCE

Here are the many possible symptoms of sulfur intolerance. It's important to note that nobody will experience ALL of these symptoms, but if you recognise yourself in quite a few of these, it would be worth trying a low sulfur diet (more on that below).

Digestive issues: reflux, gas, bloating, “bubble” sensation in the gut, focal pain in the abdomen/gut, itching and burning of anus, smelly stools.

Reactions to sulfa drugs such as certain antibiotics (Septra, Bactrim, Erythromycin-sulfisoxazole) or sulfasalazine (used for the treatment of Crohn's disease and Ulcerative Colitis). This should be a big red flag that you might be sulfur intolerant.

Anxiety, panic attacks, sympathetic dominance (mostly caused by excess sulfite).

High night cortisol.

Fatigue (too much H2S inhibits energy production).

Slow or irregular heartbeat.

Orthostatic hypotension/ low blood pressure/disliking standing up for long periods.

Heat: hot flashes, night sweats, flushing. Sleeping with feet out of the blanket.

Sleep issues: either difficulty falling asleep, or waking up after 3-4 hours of sleep. Light sleeper, easily awakened.

Skin: rashes, red cheeks, acne, hives, red stuff, itching.

Tendonitis, tight tendons and muscles, plantar fasciitis.

Poor alcohol tolerance or unique/exaggerated symptoms with alcohol. Especially those containing sulfites (white wine is higher in sulfites, beer, cider).

Brain fog.

Headaches.

Anger, irritability (especially ‘flash’ anger).

Cough (especially after eating high sulfur food).

Curvature problems: scoliosis, transverse lines in nails.

Fatty food intolerance (because of low taurine).

Frequent urination, especially at night.

Chronic pain.

Eye irritation/inflammation.

Dry red lips.

Symptoms of high ammonia: H2S production liberates ammonia, which can lead to other symptoms, such as brain fog (especially post prandial, more with animal products). Increased ammonia can also lead to decreased production of dopamine and serotonin, with symptoms such as poor concentration, depression etc.

Symptoms of histamine intolerance: Increased sulfite in the body can increase histamine production, leading to histamine intolerance symptoms. Read more about histamine.

Other symptoms that have been associated with sulfur intolerance: nightmares when sleeping on the back. Feeling that there is something living inside the gut, rectal contraction after bowel movement, ammonia smelling sweat.

GENES THAT CAN AFFECT SULFUR METABOLISM

First, there are genes in the methylation cycle that can influence sulfur metabolism. We won't go in a lot of details here as methylation is a very complex topic, but basically, if the methylation cycle is either too slow or too fast, it will influence how much sulfur goes down the transulfuration pathway.

Snps in the following methylation genes could impact sulfur:

• MTHFR
• BHMT
• MTR
• MTRR

And then there are genes in the transulfuration pathway.

• CBS
• CTH
• SUOX
• CDO
• PAPSS

IMPORTANT NUTRIENTS INVOLVED

Vitamin B6: necessary for many chemical reactions in the trans-sulfuration pathway. Both too little and too much can be an issue.

Iron: necessary for building SUOX, which is necessary for converting SO3 (sulfite) to SO4 (sulfate).

Molybdenum (Moly): required for the enzyme SUOX to function. If there is not enough moly, sulfite (SO3) will build up in the body.

Key reasons for moly deficiency:

• Not enough in the diet (very rare... only if highly processed diet).
• Can be chelated or bound up by other substances and thus rendered unusable. Glyphosate and heavy metals are mostly responsible for this.
• High alcohol intake or candida. The enzyme needed to process alcohol (ALDH) uses moly. If a lot of moly is needed for this process, little is left for SUOX to do its job. See note below as well.  

*Molybdenum is also needed by an enzyme called aldehyde dehydrogenase, which breaks down the substance that causes hangovers from drinking excessively, called acetaldehyde. If Moly is in short supply, you are likely to have an exaggerated reaction to alcohol. Acetaldehyde is also produced by candida, so moly can also be useful for people suffering from candida. You can learn more about this in the Candida & SIFO section. Other symptoms from sulfur food intake can also be worse on the day after drinking alcohol.

Vitamin B12: plays a central role, in conjunction with other B vitamins and cofactors, in the methylation cycle, converting homocysteine back to methionine. In this way, it prevents homocysteine from backing up and spilling too much into the trans-sulfuration pathway.

The form of B12 hydroxocobalamin has been shown to dramatically reduce blood levels of H2S (hydrogen sulphide), which can help a lot to reduce certain symptoms of sulfur intolerance, such as brain fog and impaired cognition.

IMPORTANCE OF EATING ORGANIC

Eating organic is important for many reasons, but we will mainly focus on glyphosate (round up).

Glyphosate has many negative impact in the body. Here are the main reasons it can affect sulfur metabolism specifically:

Nutrient depletion: Glyphosate can bind to several minerals, leading to nutrient depletion. Of significance for sulfur metabolism are iron, zinc, manganese, moly and cobalt (needed for B12).

Dysbiosis: Glyphosate can shift the balance in the gut towards more sulfur reducing bacteria (see below). It also inhibits the growth of healthy bacteria.

Eating organic can also reduce your consumption of sulphites as discussed above.

SULFUR REDUCING BACTERIA (SRB)

These bacteria can use sulfur for their energy production. When this happens, instead of producing sulfate (which the body needs), hydrogen sulphide (H2S) and sulfites (SO3) are produced, which can cause numerous health issues, as described earlier.

Issues happen when these bacteria are present in high number.  

SRB can also extract sulfur from bile (which contain the sulfur amino acid taurine) and from mucins (mucus). As mentioned above, the process of desulfating the mucins can allow them to colonise and become more pathogenic.

Most common sulfur reducing bacteria:

• Desulfovibrio
• Biolophila wadsworthia
• H.Pylori
• Enterobacter
• Campylobacter jejuni
• Staphylococcus aureus
• Escherichia coli
• Streptococcus anginosus
• Clostridium
• Klebsiella

SRB are notorious for forming sturdy biofilm, protecting them from treatment protocols. Using a biofilm destroyer is therefore important during treatment. We use biofilm as part of Clean Up Protocol #2.

LINK WITH SIBO

Many cases of SIBO are in fact hydrogen sulphide SIBO. Although hydrogen sulphide is not tested in the standard SIBO breath test, it is thought to show up as a 'flat line' on the test, with low hydrogen numbers all the way.

We have observed that people who respond very well to anti-microbials or rifaximin for SIBO treatment, feeling much better while on it, but relapse quickly as soon as they are off, may have sulfur metabolism/sulfur intolerance issues.

Greg Nigh, who has researched sulfur extensively, believes that it’s possible that many cases of SIBO are in fact an adaptation to low sulfate availability in the body.

For these reasons, we believe that a low sulfur trial is worth it for everybody with SIBO.

You can read more about SIBO here.

LINK WITH MITOCHONDRIAL DYSFUNCTION

The recycling of sulfate through the kidneys requires ATP. If you have mitochondrial issues and you’re not creating enough ATP, you can’t recycle sulfate, which then leads to a sulfate deficiency.

Vit D is also important for this process.

LINK WITH OXALATES

• High oxalate leads to glutathione depletion and mitochondrial dysfunction, which leads to low ATP and low sulfate, as described above.
• High oxalates can lead to yeast overgrowth, which depletes molybdenum.
• Depleted sulfate can lead to oxalate intolerance as well.

Read more about oxalates

LINK WITH FOOD CHEMICAL SENSITIVITY

An enzyme called PST (aka phenol-sulfotransferase) is required for the processing of phenols. Low PST activity, or an issue with sulfur metabolism/low sulfate can cause salicylates and/or histamine sensitivity.

Also, diets that are high in salicylates and/or histamine can overload sulfation, leading to low sulfate. An overgrowth of pathogens that produce histamine can also overload sulfation.

Excess sulfites can also lead to excess histamine/histamine intolerance.

Therefore, some people might benefit from a low chemical food diet for a while to improve sulfur food tolerance and reduce symptoms.

You can read more about food chemical sensitivity here.

LOW SULFUR DIET TRIAL

If you think that sulfur intolerance might play a role in your health issues, we would highly recommend trying a low sulfur diet for 1 - 2 weeks. In a very short time, you can quickly know if sulfur is an issue for you and save yourself years of trial and error with diets!

It's simple... download the PDF below and follow the instructions ;-)

There are even some low sulfur recipes in there to help you with the trial.

LAB TESTING

Although we believe that doing a low sulfur trial is the best way to determine if you may have sulfur intolerance, here are a few blood test results that could also be helpful.

Uric acid: below 4.0 for males and below 3.0 for females is suggestive of Moly deficiency.

High ratio of plasma cysteine to sulfate.

Low homocysteine (if fast CBS)

High Cholesterol (sulfate is needed for cholesterol metabolism)

USEFUL SUPPLEMENTS AND OTHER TOOLS

There are a few supplements that can be very helpful for people with sulfur intolerance. You don't need to take all of those.

The top 4 in bold are the most essential.

Molybdenum: It is best to get it in liquid form. We like Seeking Health Optimal Molybdenum Drops (AUS - USA)

Start low (1 drop/ 25 micrograms twice per day) and increase to up to 5 drops (125 micrograms twice per day).

MoZyme Forte by Biotics is also a good option, but must be chewed (1 tablet twice per day).

Hydroxocobalamin (B12): The form of B12 hydroxocobalamin has been shown to dramatically reduce blood levels of H2S. 2000 mcg (2mg) daily. It can be really useful to reduce brain fog and improve cognition.

We like Seeking Health Hydroxo B12 lozenges (AUS- USA)

Manganese: 10 mg twice per day. Helps clear ammonia. Reduces brain fog. May also help to promote the growth of lactobacillus in the gut.

* Seeking Health's Trace Mineral complex II contains both Moly and Manganese although in smaller amounts. Could be a good maintenance option (AUS - USA)

Epsom salt baths: These are a very important part of the treatment as it supplies sulfate, an easily absorbed form of sulfur, while by-passing the digestive tract. See more here.

Korean Red Ginseng: Can inhibit the enzymes that produce H2S. Can help improve energy. 1000mg twice daily with food.

Available on iherb here and here.

Capsaicin: Works on the receptor that are stimulated by H2S, including both motor and pain receptors. Can be useful for people with abdominal cramping, or when pain is a significant symptom. Use in tincture form (1 dropper 3 times daily) or in capsules, 1 cap 3 times daily.

Probiotics: The probiotics recommended in the 'Probiotics - Crowding out the bad guys section' would be very helpful.

Lemongrass: May help to suppress the growth of sulfur reducing bacteria. Can also help with anxiety and sleep. Use an organic essential oil, 3 drops twice daily. You can increase the dose every 3 days by 1 drop up to a maximum of 6 drops twice daily.

Bismuth citrate: can reduce bloating from hydrogen sulfide. Can be useful short term to reduce bloating, but shouldn't be used long term.

Butyrate: Short chain fatty acid produced by certain beneficial bacteria in our gut. People with dysbiosis often have low levels of butyrate producing bacteria. Butyrate reduces inflammation both in the gut and systematically. May help to re-establish integrity of the gut lining, which can greatly reduce food reactions. 1 gram twice daily. Butyric Cal/Mag by Biotics, EnteroVite by Apex Energetics or ProButyrate by Tesseract.

Coffee enemas: See more here.

Flaxseed powder: Inhibits two major enzyme involved in H2S production, CBS and CTH. 1 tbsp twice daily. Drink plenty of water with it.

Sulfur containing supplements that may be problematic (STOP if taking): MSM, NAC, ALA, ‘Detox’ supplements, Taurine, garlic extracts (including allicin), milk thistle, methionine.