The Urea Cycle is the body’s waste facility, clearing toxic ammonia from protein breakdown and turning it into safe urea to flush out in urine.

 

Urea Cycle – The Waste Facility

 

 

 

 

 

 

 

🗑️ The Urea Cycle – The Body’s Waste Facility

The primary and most important function of the Urea Cycle (also called the Krebs-Henseleit Cycle) is to safely remove ammonia, a highly toxic byproduct from breaking down protein. Even small amounts of ammonia can cause serious damage to the brain and body. This process takes place mainly in the liver and kidneys.

This cycle is also closely connected to the CBS pathway, a key part of the MTHFR methylation network.

Continuing with the analogy of the Urea Cycle as a waste management facility, it relies on energy from the mitochondria (the power plant) to function. It also collaborates with the previous cycle, BH4, which shares resources to help the Urea Cycle effectively clean out ammonia.

Additionally, this collaboration supports NOS (Nitric Oxide Synthase)—think of it as the Waste Management Supervisor—to produce nitric oxide, a molecule that keeps blood vessels healthy and flexible. Nitric oxide helps prevent plaque buildup, reducing the risk of strokes, heart disease, and circulation problems.

Looking at Alex’s results on CBS:

CBS

699 C>T

TC

impacted

Now, if your CBS is not working properly, and the “waste” spills over to form free radicals, of which superoxide and Peroxynitrate are the most destructive to healthy cells. This can cause the following defects:

• N-acetylglutamate synthase deficiency (Hyperammonemia, type 111 or NAGS deficiency: an inherited disorder that causes ammonia to build up in the Blood i)
• Carbamoyl phosphate synthetase deficiency (congenital Hyperammonemia, type 1: i)
• Ornithine transcarbamoylase deficiency (OTC deficiency: i)
• Citrullinemia (Deficiency of argininosuccinic acid synthase: i)
• Argininosuccinic aciduria (Deficiency of argininosuccinic acid lyase: i)
• Argininemia (Deficiency of arginase: i)
• Hyperornithinemia, hyperammonemia, homocitrullinuria syndrome (Deficiency of the mitochondrial ornithine transporter: i)

⚠️ Urea Cycle Disorders & Uric Acid 

Most urea cycle disorders (UCDs) are associated with hyperammonemia, which means dangerously high levels of ammonia in the blood. However, not all UCDs present this way — for example, argininemia and some forms of argininosuccinic aciduria may occur without elevated ammonia levels.

A common condition linked to dysfunction in waste elimination—though not directly a urea cycle disorder—is gout. In gout, there’s a buildup of uric acid, which forms crystals that cause pain, swelling, and inflammation in the joints.

Uric acid is created when the body breaks down purines, natural compounds found in both your own cells and certain foods. Normally, the body eliminates uric acid through urine, but when this process is impaired or overwhelmed, it leads to painful uric acid buildup.

🔍 Important Clarification:

The urea cycle primarily removes ammonia (from nitrogen waste), while uric acid buildup (as in gout) is related to purine metabolism, a separate waste pathway. However, both systems are part of the body’s larger detox and waste management network, and dysfunction in one can often stress the other.

So, what food can you eat to lower purines and ammonia in your body?

🍎 Food Chart to Lower Purines (Uric Acid) and Ammonia (Support Urea Cycle)

Goal	Eat More Of	Limit / Avoid
Lower Purines	– Cherries, berries, citrus- Leafy greens, cucumbers, bell peppers- Whole grains (oats, barley, brown rice)- Nuts and seeds- Low-fat dairy- Herbs (ginger, turmeric)- Plenty of water	– Organ meats (liver, kidney)- Red meat (pork, lamb)- Anchovies, sardines, shellfish- Beer, alcohol- Sugary drinks- Processed and fried foods
Lower Ammonia	– Cruciferous veggies (broccoli, cauliflower)- Leafy greens, beets- High-fiber foods- Fermented foods (sauerkraut, kimchi, miso)- Liver-support herbs (dandelion, turmeric)- Hydrating foods (watermelon, cucumber)- Lemon water, herbal teas (milk thistle, nettle)	– Excess protein- Processed meats (bacon, sausage)- Alcohol- Junk food and high-sugar items- Very high protein keto diets without balance

🚀 Key Support Nutrients:

• Vitamin C (lowers uric acid)

• B vitamins (Folate, B12, B6) (supports ammonia detox)

• Zinc, magnesium (enzyme cofactors)

• L-ornithine, L-arginine, L-citrulline (supports the urea cycle)

🚰 Hydration is crucial for flushing both uric acid and ammonia.

 

🧬 CBS and Autism 

The CBS gene (Cystathionine Beta-Synthase) controls an enzyme involved in the transsulfuration pathway, which is a branch off the methylation cycle. This pathway is responsible for helping the body:

• Process homocysteine into cystathionine, leading to glutathione (the master antioxidant)

• Remove ammonia, a toxic waste product

• Regulate sulfur compounds, which are vital but can become harmful in excess

⚠️ CBS Upregulation in Autism

In many individuals with Autism Spectrum Disorder (ASD), the CBS enzyme tends to be overactive (a “CBS upregulation”). This causes the pathway to dump homocysteine too quickly into sulfur pathways, leading to:

🔥 Common Issues Seen with CBS Upregulation:

• High ammonia levels → Brain fog, irritability, poor focus, behavioural swings

• High sulfur levels → Sensitivity to sulfur-rich foods (garlic, onions, eggs) and supplements (like NAC, MSM, glutathione)

• Low glutathione if the pathway is overwhelmed → Poor detox, oxidative stress, and  immune challenges

• Low homocysteine levels, which disrupt methylation balance → Affecting mood, focus, and detox

🧠 How CBS Issues Affect Autism Symptoms:

• Increased sensory sensitivity, irritability, and hyperactivity

• Trouble detoxifying → worsened reactions to toxins, heavy metals, or chemicals

• Ammonia buildup can cause neurological symptoms, including meltdowns, sleep issues, or cognitive fog

• Gut issues and poor sulfur processing can lead to discomfort and mood swings

🌱 Supporting CBS Balance in Autism:

🚦 Balance is Key:

CBS upregulation often shows up alongside MTHFR, COMT, and other methylation gene issues. It’s like a traffic jam — if one road is blocked or flowing too fast (like CBS), it affects the whole detox and methylation network.

🏗️ In Simple Terms:

CBS in autism is like an overactive waste chute — it tries to clean out too fast, creating sulfur buildup, ammonia overload, and stress on detox pathways. Gentle support of ammonia clearance, sulfur balance, and methylation helps calm the system.

PLEASE NOTE: ANY VIEWS REGARDING THE RESULTS ARE MY UNDERSTANDING AND DO NOT SERVE AS PROFESSIONAL ADVICE. THE TREATMENT RECOMMENDATION IS STRICTLY RELATED TO ALEX’S RESULTS AND NOT MEANT FOR SELF-TREATMENT. ALWAYS SPEAK TO YOUR HEALTHCARE PROVIDER BEFORE STARTING ANY TREATMENTS.