What Should I Eat with Trimethylaminuria?

Trimethylaminuria (TMAU), or 'fish odor syndrome,' is a metabolic disorder where the body cannot properly break down the compound trimethylamine, according to the NHS. A low-choline diet is the primary dietary strategy to reduce the production of this malodorous chemical and minimize symptoms.

Quick Summary

This article outlines a dietary strategy for managing trimethylaminuria (TMAU), focusing on limiting high-choline foods, specific seafood, and certain vegetables. It provides a list of foods to enjoy, offers meal ideas, and compares food choices to help individuals effectively manage symptoms.

Key Points

• Reduce Choline and Carnitine: The primary dietary strategy is to limit foods high in TMA precursors like choline (in egg yolks, liver, legumes) and carnitine (in red meat) to minimize odor.

• Avoid Marine Seafood: Marine fish and shellfish contain high levels of TMAO, which gut bacteria convert to TMA, so these foods should be strictly avoided.

• Focus on Low-Choline Alternatives: Enjoy plenty of fruits, most vegetables (except Brassicas), low-choline grains, and dairy alternatives to build a balanced meal plan.

• Consult a Dietitian: It is essential to work with a healthcare professional to ensure a low-choline diet remains nutritionally adequate and prevents deficiencies.

• Consider Other Treatments: Beyond diet, other strategies like using acidic soaps, taking specific supplements, and managing stress can help control TMAU symptoms.

• Assess Individual Tolerance: Some foods, like Brassica vegetables, may affect people differently. Careful monitoring of individual reactions is crucial for fine-tuning the diet.

Understanding Trimethylaminuria and Your Diet

Trimethylaminuria (TMAU) is a condition that results from a genetic or metabolic issue affecting the FMO3 enzyme in the liver. This enzyme is responsible for converting trimethylamine (TMA), a smelly chemical produced by gut bacteria, into its odorless form, trimethylamine N-oxide (TMAO). When the FMO3 enzyme is deficient or non-functional, TMA builds up in the body and is released through sweat, urine, and breath, causing a distinct, unpleasant odor.

The key to managing this condition through diet is to reduce the intake of TMA precursors—substances that gut bacteria convert into TMA. The most notable of these are choline and carnitine. Therefore, successful dietary management involves identifying and limiting foods high in these compounds.

The Role of Choline and Other Precursors

Choline is an essential nutrient found in many foods, but in those with TMAU, excess amounts can exacerbate symptoms. Carnitine, another amino acid derivative, can also be converted to TMA by gut bacteria. Furthermore, marine seafood naturally contains high levels of TMAO, which gut bacteria can reduce back to TMA. By being mindful of these dietary components, individuals can significantly impact their odor symptoms.

Low-Choline Foods to Enjoy

Focusing on nutrient-dense, low-choline foods is key to maintaining a balanced and healthy diet while managing TMAU. Here is a list of excellent food choices:

• Grains and Starches: Most carbohydrates are naturally low in choline. Opt for breads, pastas, rice (white or brown), oats, potatoes, and non-bran cereals.
• Fruits: Nearly all fruits are very low in choline and can be eaten without restriction. This includes apples, bananas, pears, grapes, and berries.
• Vegetables: The majority of vegetables are low in choline, with the notable exception of the Brassica family. Enjoy a wide variety, such as lettuce, carrots, spinach, tomatoes, cucumbers, and zucchini.
• Dairy Alternatives: While dairy products can be relatively low in choline, choosing alternatives like almond, rice, or coconut milk can be beneficial, especially if fortified with calcium.
• Protein Sources (Moderate Intake):
  • Egg Whites: The yolk is high in choline, but the whites are a safe and high-protein option.
  • Freshwater Fish: Unlike marine fish, freshwater fish (e.g., trout) contain lower levels of TMAO and are a good protein source.
  • Plant-Based Proteins: Lentils, chickpeas, beans (in moderation), and tofu are generally lower in choline than animal protein sources.

Foods to Avoid or Limit Strictly

To reduce TMA production, it is crucial to limit or avoid foods and supplements that are high in TMA precursors. These include:

• Seafood and Shellfish: Marine fish, squid, octopus, crabs, and lobsters are high in TMAO and should be completely avoided.
• Egg Yolks: These are very high in choline and are a primary source to limit.
• Offal: Liver, kidney, and other organ meats are extremely high in choline and should be avoided entirely.
• Legumes: Peanuts, soybeans, and other beans are high in choline and should be eaten sparingly, if at all.
• Brassicas: Vegetables in this family, such as broccoli, cauliflower, cabbage, and Brussels sprouts, can inhibit the FMO3 enzyme and may increase symptoms. Tolerance can vary, so it's advisable to test your individual reaction to these.
• Supplements: Avoid supplements containing high doses of choline, lecithin, or L-carnitine.
• Specific Milk: Milk from wheat-fed cows may contain high levels of TMA and should be avoided.

Dietary Comparison: High vs. Low Choline

This table provides a quick reference for making better food choices for TMAU management.

Food Category	High-Choline/High-TMAO Option	Low-Choline/Low-TMAO Alternative
Protein	Egg yolks, liver, marine fish, red meat	Egg whites, freshwater fish, lentils, beans (limited)
Dairy	Milk from wheat-fed cows	Rice milk, almond milk, fortified dairy substitutes
Vegetables	Broccoli, cauliflower, cabbage	Most other vegetables, including lettuce, carrots, potatoes
Fats	Fish oil supplements	Olive oil, coconut oil, sunflower oil
Snacks	Peanuts, soy products	Fruits, nuts (not peanuts), low-choline crackers

Essential Dietary Considerations for TMAU

When adopting a low-choline diet, it's essential to do so under the guidance of a healthcare professional, such as a registered dietitian. Restricting too many foods without professional supervision can lead to nutritional deficiencies and unintended weight loss. A dietitian can help create a balanced meal plan that meets your protein, vitamin, and mineral needs.

Moreover, the dietary needs of individuals can vary based on the severity of their FMO3 deficiency or individual tolerances. Some people may find they can tolerate small amounts of certain restricted foods, while others must avoid them completely. The diet should be viewed as a tool for symptom control, not a one-size-fits-all solution. For more information on the genetic aspects of TMAU, the National Human Genome Research Institute offers detailed resources.

Sample Low-Choline Meal Plan

• Breakfast: Oatmeal with sliced banana and a splash of almond milk.
• Lunch: A large salad with mixed greens, chopped vegetables, and grilled chicken breast (moderate portion).
• Dinner: Stir-fried vegetables with tofu and white rice. Use low-choline oils like olive or sunflower oil.
• Snacks: A piece of fruit like an apple or some grapes.

Beyond Diet: Other Management Strategies

Diet is a cornerstone of managing TMAU, but other treatments can also help alleviate symptoms:

• Hygiene: Using slightly acidic soaps (pH 5.5–6.5) can help neutralize TMA on the skin. Frequent washing of clothes can also help.
• Supplements: Some doctors may recommend short courses of certain supplements, such as activated charcoal or riboflavin (Vitamin B2), to help manage symptoms.
• Antibiotics: Short courses of antibiotics can reduce the TMA-producing bacteria in the gut and are sometimes used under medical supervision.
• Stress Management: High stress levels can exacerbate sweating and potentially worsen the odor, so relaxation techniques are recommended.

Conclusion

For individuals wondering what should I eat with trimethylaminuria, the answer lies in adopting a balanced, low-choline and low-TMAO diet. This involves being mindful of food choices, especially limiting marine seafood, egg yolks, offal, and certain legumes. While diet is a powerful management tool, it is not a cure and should be undertaken with professional dietary guidance to prevent nutritional deficiencies. By combining a tailored diet with other personal hygiene and stress management strategies, individuals with TMAU can effectively control their symptoms and significantly improve their quality of life.

Frequently Asked Questions

What foods are highest in choline?

Foods with the highest concentration of choline include egg yolks, liver, kidney, peas, beans, peanuts, soy products, and supplements containing lecithin.

Can I eat fish with trimethylaminuria?

You must avoid marine (sea) fish and shellfish, as they are high in trimethylamine N-oxide (TMAO), a precursor to TMA. Freshwater fish, however, contain lower levels of TMAO and are generally considered safe to eat in moderation.

Are all vegetables off-limits on a low-choline diet?

No, most vegetables are very low in choline. The main group to be cautious of is the Brassica family, which includes broccoli, cauliflower, cabbage, and Brussels sprouts, as they can inhibit the FMO3 enzyme in some individuals.

Is soy safe to eat with TMAU?

Soy products are high in choline and should be avoided or severely limited. This includes tofu, edamame, and soybeans.

Can activated charcoal help with trimethylaminuria?

Some doctors may recommend a short course of activated charcoal, as it can bind to trimethylamine in the gut and help reduce odor.

What kind of soap should I use for TMAU?

Using slightly acidic soaps or shampoos, with a pH between 5.5 and 6.5, is recommended. This helps neutralize the alkaline TMA on the skin's surface and can reduce body odor.

Is it possible to cure trimethylaminuria with diet?

No, there is currently no cure for TMAU. Dietary changes are a management strategy to reduce the odor symptoms by limiting the production of trimethylamine. It's a lifelong condition that can be effectively controlled with proper management.