If you have histamine intolerance, a leaky gut, or a compromised immune system, unsafe food handling practices may be the underlying cause of your histamine intolerance.
Two different pathways produce histamine.
One is naturally occurring in some fresh food products (such as tomatoes, eggplant, and spinach), and the second is by pathogenic microorganisms.
Bacteria is present in most food of animal origin (such as fish, meat, eggs, and cheese), but when fresh, the levels are harmless even when histamine intolerant.
Given the right conditions, however, bacteria can multiply quickly.
Sometimes this is deliberate via fermentation. Sometimes it is unplanned, through poor food handling practices or cross-contamination.
Poor food handling practices may also cause pathogenic gut infections, the leading cause of histamine intolerance in my clients.
For example, gut test infections can be linked to poor food handling or cross-contamination.
Some simple steps can stop you from accidental histamine food poisoning.
Bacteria are everywhere.
Most are harmless, many are beneficial, but some are pathogens that release histamine, tyramine, or other biogenic amines.
Pathogenic bacteria multiply by splitting themselves in two. In the right conditions, one can become 2 million in less than 7 hours, leading to high histamine levels.
Once formed, we cannot destroy histamine-producing bacteria in food, merely halt it.
Histamine and Gut Infections
The immune system attends to incidental pathogen exposure in a person otherwise well. There is no problem.
Add in other stressors (such as low hydrochloric acid, low bile production, dysbiosis, viral infections, food intolerances (especially gluten), dental plaque, nutritional deficiencies, medication use, lack of sleep, and stress), and your gastrointestinal, immune system becomes overwhelmed.
Now it’s a problem. Pathogenic bacteria can then become relocated into the gastrointestinal tract, where it continues to produce histamine, tyramine, and other biogenic amines.
Pathogenic bacteria are a leading cause of histamine intolerance in my client base. The good news is that expelling these pathogens and restoring the gastrointestinal immune system often reverses histamine intolerance.
Bacteria need certain conditions to thrive, including:
Bacteria need food to grow.
The type of food a bacteria thrives on differs depending on the type of bacteria and the food’s pH.
Most bacteria thrive in an acidic Ph with an optimum pH between 4 and 5.5. This pH does not mean that the diet needs to be alkaline, simply that food handling needs to be better observed in acidic foods.
Cooked grains, dairy products, meat, fish, seafood, and coffee (especially coffee pods) provide the acidic environment in which histamine-producing bacteria thrive.
Fruit and vegetables are not acidic – and food handling practices can be more relaxed.
Histamine intolerant people may, for example, tolerate leftovers of fruits and vegetables.
Bacteria cannot survive without some form of moisture (such as water). Without moisture, bacteria stop growing.
For centuries, salting, dehydrating, and smoking techniques have been used to remove moisture from foods and prevent histamine-producing bacteria from growing. It also means that bacteria can survive in water.
Treated tap water does not kill all parasites. Boiled, filtered (preferably with a PurOne or Berkey filter – with the fluoride addition), and reverse osmosis water (with added minerals), are generally safe.
Prewashed foods, such as store-bought bagged lettuces, are at high risk of contamination due to moisture content.
Storing foods in air-tight containers can dramatically improve food safety as any bacteria is starved of oxygen.
Temperature and Time
Temperature abuse has a decisive impact on histamine production and is the most critical factor to monitor, particularly for animal protein.
The time that animal protein is exposed to temperature abuse will determine the ultimate level of histamines.
Control the temperature during transportation, storage, and food processing; you essentially control the histamine levels.
The effect of temperature on food has been extensively researched. Animal products at between 5 – 60 degrees Celsius (40 – 140 Fahrenheit) are in danger of producing histamines and biogenic amines.
Once formed, histamine is difficult to destroy. Therefore, if histamine accumulates in the product before cooking, it will be there after cooking.
It is possible, however, to stop it from reproducing. Refrigerating or freezing foods (at 5 degrees Celcius or under) significantly slows replication. Freezing animal products is the best weapon to reduce histamine.
While cooking foods above 75 degrees, Celcius halts histamine replication, which has several practical implications for safe food handling.
1. Food Transportation
The temperature at which produce is held (mainly dairy products, meat, fish, and seafood) between the time it is processed, and eaten, often defines the histamine levels of fresh produce.
Fish can be eaten if gutted within twelve hours of the catch, and not temperature abused (by storage above 5 degrees Celcius) in the supply chain is generally safe.
Chicken, rabbit, lamb, and other lower histamine animal proteins, which do not require hanging to be edible, are generally safe provided they have not been temperature-abused in the supply chain.
The larger the animal, the longer it needs to be hung to be edible, and therefore the longer it is exposed to temperature abuse. This principle is why histamine intolerant people more easily tolerate smaller animals.
As a general rule, sourcing animal protein locally, as opposed to from long distances, minimizes the chance that there will be a breakdown in the supply chain.
We are also part of the supply chain. Transporting animal products briefly in a cooler bag, then placing them straight into the fridge or freezer, ensureS that we are not part of the supply chain breakdown.
2. Food Storage
Freezing foods halts histamine production. The room temperature is in the danger zone. Generally, leftovers of animal products and cooked acidic grains may be problematic.
In comparison, we may tolerate leftovers of fruit and vegetables. We should also store food in air-tight (glass) containers in the fridge or freezer.
3. Thawing Foods
Thawing foods, which require exposure to danger zone temperatures, presents a challenge.
A 2017 study looked at three methods of thawing fish; immersion in water, cold water, and room temperature.
It was found that thawing in cold water minimized histamine levels. Also that gutting the fish reduced histamine formation. Foods can be defrosted using a cold water bath.
Produce should be placed in leak-proof packaging and submerged in cold tap water. We should change the water every 30 minutes to ensure the product stays cold.
The study did not look at defrosting in the fridge. However, this is likely to be another viable and more practical alternative, although it will take longer.
4. Cooking Methods
The cooking method of animal protein (rather than other foods – where there is much more latitude) is essential.
All raw animal protein should be thoroughly cooked at a temperature above 75 degrees Celcius before eating.
A 2017 Korean study looked at different cooking methods. The study suggested cooking methods of animal protein (such as grilling or frying) that remove water concentrated (rather than increased) histamines. The study was far from conclusive.
I mention this study because these findings were more or less consistent with studies looking at the effect of cooking methods on anti-nutrients.
An animal protein grilled, broiled, roasted, seared, or fried is at higher risk of anti-nutrient formation.
To retain moisture, an animal protein that is cooked at under 120 degrees Celcius (250 Fahrenheit), especially when steamed or cooked in liquid, will not form anti-nutrients.
In summary, cooking animal protein will halt histamine formation. How you cook animal protein will optimize nutrition.
Histamine Cross Contamination
Cross-contamination occurs when bacteria is moved from one object to another and is an often-overlooked means of acquiring pathogenic bacteria.
We are mainly concerned with raw dairy products, meat, fish, and seafood. But also soil/dirt-based bacteria which is not always beneficial.
So, for example, a chopping board with raw meat on it and not being appropriately cleaned will continue to fester. The next time you use it, the bacteria will have multiplied and likely relocated onto what you are cooking.
Another example is a dishcloth, which is used to wipe down the same chopping board, and then left to fester. The next time you use the dishcloth, the bacteria will multiply and likely be relocated onto what you cook next.
Cleaning removes residues, but it does not remove bacteria. We can remove bacteria by sanitizing with a temperature greater than 75 degrees Celcius or applying a 3% hydrogen peroxide solution. A dishwasher set on a hot cycle achieves this effortlessly.
Returning to the chopping board example, remove the debris, rinse with running water and detergent, wipe with a 3% hydrogen solution, rinse it, and air-dry it, and you’re all good.
A word about soil. Soil contains many microbes which are integral to soil health. However, not all soil microbes are necessarily beneficial.
Eating unwashed fruit and vegetables is not a problem in a healthy person, as they have the immune system to sort the good from the bad.
However, when you histamine intolerant or immune compromised, there is a good chance that you cannot. So yes, I’m suggesting you wash your fruit and vegetables.
Here are a few basic rules to minimize cross-contamination:
1. Food Preparation
Consider all raw foods as contaminated
Store raw foods separately or store raw foods below cooked foods in the refrigerator
Use separate preparation areas for raw and cooked foods
Never use the same equipment for raw and cooked foods
Don’t return tasting spoons to the cooking pot or use them in food preparation
Always wash your hands after working with raw food
Wipe down all kitchen benches immediately after preparing meals
Empty garbage and clean the bin daily.
2. Fruit and Vegetables
Wash thoroughly all fruit and vegetables before use.
Place vegetables in a sink of cold water with ¼ cup of 3% hydrogen peroxide or baking soda and soak for 20 minutes.
Rinse in cold water and then use them.
Dirty dishes should not be left in the sink overnight.
If hand washing dishes, do so under running water, not in a full sink.
Tea towels harbor bacteria, so air-drying dishes are preferable.
Dishcloths harbor bacteria and are common cross-contamination, so we should change them frequently.
These safe food handling practices are not unique to histamine intolerance. At least in Australia, they are the standards required of any food handling business. However, if you have histamine intolerance there is less room for error.
Histamine is naturally occurring in some fresh food products (such as tomatoes, eggplant, and spinach) but also unintentionally in some food (mainly dairy products, meat, fish, and seafood) that has been temperature abused or cross-contaminated.
Safe food handling practices can dramatically reduce the histamine content of foods allowing more foods to be kept in the diet.
To learn more about how food handling affects our histamine levels, check out my blog post, Easy Protein Swaps: That Lower Histamine Without Cutting Foods.
Roseiro, C., Santos, C., Sol, M., Silva, L. and Fernandes, I. (2006). Prevalence of biogenic amines during ripening of a traditional dry fermented pork sausage and its relation to the amount of sodium chloride added. Meat Sci., 74(3):557–563.
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