Dr. Amy Yasko, a physician specializing in nutrigenomics for autistic children, has put forth a theory based on her experience that says that being homozygous (AA alleles) for CBS C699T causes difficulties with excess ammonia in the body.
Most of what’s written here is about that perspective, but it is worth noting that at least one researcher has written a detailed paper on why he disagrees with her assessment.
Having the AA alleles for the CBS gene, Dr. Yasko says, results in the body not detoxing ammonia well enough. As issues related to this problem, taurine levels and sulfur groups may be high. She recommends that people with CBS have the sulfite levels in their urine tested. You can also test your own urine for sulfites at home by purchasing sulfite test strips. If urinary sulfates are greater than 800-1000, high CBS activity is likely.
If urinary sulfite levels are too high, she recommends avoiding the following foods and supplements until the problem is under control. This may be difficult, as people with CBS tend to crave sulfur-rich foods:
- Milk thistle
- Anything “sulfate”
- Alpha lipoic acid
- Brussels sprouts
- Coconut oil or milk
- Dried beans
- Epsom salt baths
- NAC (N-acetylcysteine)
Nutrients those with CBS should make sure they have enough of include molybdenum and manganese.
Molybdenum is required to detox all the sulfites and aldehydes in your system. It also keeps your copper to zinc ratio in balance. Low molybdenum levels makes it harder for your body to detox aldehydes, which come from a variety of sources, such as candida overgrowth, perfumes, vanilla, cinnamon, cumin, tarragon and alcoholic drinks.
Manganese tends to be low when there’s excess ammonia in the body. Some signs of manganese deficiency include:
- Low cholesterol (there is such thing as cholesterol that is too low, contrary to what many doctors will tell you. Cholesterol is needed to make hormones.)
- Elevated alkaline phosphate levels
- Poor T-cell mediated immune system function (This is caused by thymus issues resulting from low manganese.)
- Difficulties with dopamine and insulin synthesis, since when manganese gets used up detoxing ammonia, none is left for producing dopamine or insulin.
Those with CBS tend to have low homocysteine because it is converted into taurine too quickly. They also may have low levels of BH4, which causes low nitric oxide. Low BH4 is associated with high blood pressure, arteriosclerosis and severe parasite infections. BH4 is available as a prescription medication called Kuvan. The generic name is sapropterin dihydrochloride. This drug is usually prescribed to people with PKU.
Other effects of CBS include low citrulline, low methionine and excessive levels of phenylalanine.
Substances that could help people homozygous for CBS, Dr. Yasko says, include:
- EDTA in low doses, which helps the body produce glutathione instead of taurine
- CoQ10 (although this should be monitored because it is a lipid donor- see below)
- Yucca root
- Ammonia Support RNA, a product Dr. Yasko sells (but it’s $85…yikes!)
- Activated charcoal
- Alpha ketoglutarate
- Arginine (but don’t take this if you have the NOS mutation)
- Curcumin (curcumin is, however, a methyl donor, so it may not be suitable for everyone with a CBS mutation)
She recommends that people with CBS monitor lipid donors, such as:
- Alpha lipoic acid
- High doses of essential fatty acids (EFA’s)
- Lipoceutical EDTA or glutathione
- Transdermal creams
She also recommends that people with CBS monitor their use of supplements that contain methyl groups, such as:
- Methyl B12
What’s at Risk in Those with a CBS C699T Mutation?
People with this mutation may have excessive production of ammonia, urinary sulfites and low levels of glutathione. If you have this mutation, you should monitor your urinary sulfite levels and your vitamin B6 levels.
Excess sulfur can cause fragile red blood cells, which burst too easily, leading to anemia. It can also cause problems with substances that are sulfur donors, like DHEA or sulfur chelators like DMPS. Signs of sulfur toxicity include broken capillaries, excessive bruising and/or bleeding and impaired blood sugar regulation.
It’s interesting that in studies on mice, mice in ketosis showed a 200% reduction in CBS activity.