Histamines... Food Sensitivity
Updated: Feb 25
WHAT ARE HISTAMINES?
Like all of the sections on this site, I thought that it was important as an autism parent to be aware of histamines. Histamine intolerance is very common in children with autism, for various reasons that you'll see below. Knowledge is power. And whilst all of these food sensitivities are important to know about. It is equally important to understand that a very restricted diet, food anxiety/fears, are also not a sustainable healthy way to live. Food sensitivities are usually part of a much bigger issue, as you will see. Restricted diets should only be a temporary measure whilst healing is taking place, if necessary. It is good to be armed with this information when looking at symptoms and root causes. I hope it helps.
Histamine is a chemical that can be found in almost every living organism. It is produced by mast cells and plays a very important part in the body's immune response.
Think of histamine as the 'irritating chemical'. It is found in stinging nettles, and also found in the venom of many insects, such as bees and wasps.
Thanks to histamine, you itch and swell when you make contact with nettle leaves. In the human body, histamine is found in almost every tissue, and most of it is stored as granules in the mast cells, as well as the basophils and eosinophils (the white blood cells). Once the histamine gets released from these granules, it immediately starts producing different effects such as muscle contraction, blood vessel dilation, gastric acid stimulation etc within the body. Histamine also acts as a neurotransmitter and is in charge of transferring chemical messages to the nerve cells.
HISTAMINE'S ROLE WITHIN THE BODY;
Defence mechanism
It helps the body to defend itself from invaders, such as viruses, bacteria, or other harmful foreign bodies.
Inflammatory response
One of histamine's most important effects is its ability to dilate blood vessels and cause swelling around the site of the foreign invader, for example, a sting or bite. This is the inflammatory response and is how your body heals. The dilated blood vessels increase blood flow and lead to the immediate delivery of white cells to the site of the sting/bite.
Sleep/wake regulation
Histamine is a neurotransmitter. Its function in the brain is to support wakefulness and reduce symptoms of sleep. Hence, antihistamines usually cause a sedative effect. Overproduction of histamine can be a large part of the reason some children with autism struggle falling asleep at night.
Release of gastric acid
Histamine triggers the release of stomach acid to help digestion
Histamine has many important functions within the body. The way to think about histamine in our bodies is like a bucket of water. As long as the bucket is not overfull, everything is fine. But if you pour in more water than the bucket can hold, everything overflows.
As long as we do not make or consume more histamine than our histamine bucket can hold and our enzymes, such as DAO - (See below) can process, all is fine. But if we consume or make more than our bucket can hold (and our enzymes can process) the bucket will overflow, and we will experience symptoms.
HISTAMINE INTOLERANCE
What is histamine intolerance?
When people have an intolerance, it usually means that their bodies are sensitive to something. An example is lactose in milk. The body cannot digest lactose, and so the body becomes very sensitive to milk products. Histamine intolerance is different in that the intolerance isn't because we can't tolerate histamine or that we are sensitive to histamine - it means we have too much histamine.
When histamine levels increase too much, it impacts our health adversely. In order for histamine to function effectively within the body, it needs to be broken down. If our body can't break it down histamine effectively or quickly, it begins to build up.
I have linked some resources below related to histamine and autism health. Histamine intolerance is very common in children with autism due to bacterial imbalances and common deficiencies in key nutrients required to break down histamine effectively, caused by picky eating and or impaired detox pathways.
The enzymes that break down histamine - DAO and HMT
DAO AND HMT
Diamine oxidase (DAO) is the major enzyme involved in processing histamine and is responsible for ensuring a steady histamine level required for the balance of several chemical reactions taking place in the body. DAO is the key enzyme responsible for the degradation of histamine, regardless of whether the histamine originates from allergy-induced processes in the body or is consumed with food. This is in charge of breaking down histamine in the small intestine.
N-Methyltransferase (HMT) is the major enzyme responsible for breaking down histamine in the central nervous system.
Where Does Histamine Come From?
FOODS AND PRODUCTS;
Meat, poultry, fish, egg. Fish and shellfish, whether fresh, frozen, smoked or canned. Processed smoked and fermented meats, such as ham, bacon and sausages. Leftover food protein based food.
Milk and milk products. Cheese of any kind, yoghurt, buttermilk, kefir
Fruits. Orange grapefruit, lemon, lime, cherries, grapes, strawberries, apricots, avocado, raspberries, pineapple, cranberries, prunes, loganberries, dates, raisins, currants
Vegetables. Tomatoes, soy and soy products, spinach, red beans, aubergine, olives in vinegar or brine, pumpkin, pickles, relishes, and other foods containing vinegar
Food additives. Artificial food colours, preservatives, especially benzoates and sulphites
Seasonings. Cinnamon, cloves, vinegar, chilli powder, anise, curry powder, nutmeg
Miscellaneous. Fermented soy products such as soy sauce, miso, fermented foods such as sauerkraut, tea (regular or green), chocolate, cocoa, and cola drinks, alcoholic beverages of all types
Toiletries and cosmetics containing cinnamaldehyde, Balsam of Peru, benzoates of any type, sulphites and dyes
Medication. Some antidepressants, asthma medication, anti-hypertensive drugs
THE BODY CELLS AND SYSTEMS;
Histamine is produced by histidine, one of the twenty essential amino acids present in the human body. This process happens when the enzyme histidine carboxylase acts on the amino acid histidine.
THE MICROORGANISMS IN THE COLON
There are many bacteria in the human colon that are capable of producing histamine.
POSSIBLE CAUSES OF HISTAMINE INTOLERANCE
Foods that block DAO enzymes or trigger histamine release
Foods that trigger histamine release:
Alcohol, bananas, chocolate, cow’s milk, nuts, papaya, pineapple, shellfish, strawberries, tomatoes, wheat germ, artificial preservatives and dyes
Foods that block DAO enzymes:
Alcohol, energy drinks, black tea, mate tea, green tea
Bacterial overgrowth, such as SIBO (Small intestinal bacterial overgrowth).
Some gut microbes produce high amounts of histamines as a byproduct of their metabolism.
This bacteria grows when food isn’t digested properly, causing overgrowth of histamine-producing strains.
Click here for info on SIBO and DAO. https://www.drbenlynch.com/sibo-histamine/
Medications that prevent the production of DAO or block its functions
Medications such as;
Non-steroidal anti-inflammatory drugs (ibuprofen, aspirin)
Some antidepressants
Immune modulators
Antiarrhythmics
Antihistamines (Such as Benadryl)
Histamine (H2) blockers
Gastrointestinal disorders, such as leaky gut syndrome and inflammatory bowel disease
Intestinal permeability creates major inflammatory stress in the body, which can contribute to poor DAO function.
Deficiencies in zinc, copper, magnesium, vitamin C, B12, B6
These are common deficiencies in children with autism and are all important in either the
metabolism or functioning of DAO. Deficiencies in these can cause improper functioning of DAO and the impaired histamine processing - leading to symptoms.
It is important to note that sugar competes with vitamin C in the body. Decreasing sugar in the diet can have a positive impact on vitamin C levels.
Some strains of probiotics, such as Lactobacillus bulgaricus, Lactobacillus casei and Lactobacillus reuteri
Some probiotics are histamine producers. We learned this the hard way with Rose. Starting a new probiotic we assumed would be useful. Rose reacted very badly and was up until 10 pm screaming in distress. It took a lot of digging and research to uncover that histamine was the cause.
GENETICS/ IMPAIRED METHYLATION
Some children will be genetically susceptible to histamine intolerance.
DAO: Diamine oxidase (DAO) is an enzyme that is critical for the breakdown of histamine - if the gene that produces this enzyme is mutated has an (SNP) it can impair the function of the DAO enzyme.
Remember that environment impacts gene expression too, and even when these pathways are impaired, there are many things that can be done to reverse negative symptoms. If your child is predisposed, this means the chances of histamine intolerance becoming an issue are more likely, particularly if your environment (food, stress, toxin exposure, gut function) is not optimal.
INFECTIONS SUCH AS H.PYLORI
Heliobacter pylori is a species of bacteria that can live in your digestive tract. H. pylori typically infects your stomach and produces histamine. Children with H. pylori may exhibit no symptoms. You can ask your doctor for a stool test analysis if you are concerned about H. pylori.
UV LIGHTS
Recent research suggests that UV light can trigger additional histamine release. If exposed to it frequently, the child may become histamine intolerant.
Some Symptoms of Histamine Disorders
Headaches/migraines
Difficulty falling asleep, easy arousal
Hypertension
Vertigo or dizziness
Arrhythmia, or accelerated heart rate
Difficulty regulating body temperature
Anxiety
Nausea, vomiting
Abdominal cramps
Flushing
Nasal congestion, sneezing, difficulty breathing
Abnormal menstrual cycle
Hives
Fatigue
Tissue swelling
Bad reaction after eating fermented food like sauerkraut
Physical reaction like hives or emotional reaction like anxiety and hyperactivity if consuming citrus foods
HOW DO I KNOW IF MY CHILD HAS HISTAMINE INTOLERANCE?
As I always say, there is nothing more powerful than a simple food diary!
I have seen huge improvements in our tolerance to histamine since focusing on other areas of our health, such as gut health - as always remember that the dietary changes you may have to make don't need to be permanent. Histamine can be a symptom of other issues within the body that can be addressed.
Look for clues in your diary. Your child is always your best guide at navigating their health.
The worst offenders for us were: dried fruits in high quantities, food that has been cooked and then reheated a few days after (histamine increases with decreasing freshness of foods), all alcohol, but especially wine (not likely to be administering this to our kids, hopefully!). A histamine reaction isn't always immediate. This is why it is sometimes difficult to pinpoint.
A food diary will definitely show patterns, and you can adjust your lifestyle accordingly
There are lab tests, which analyse the stool or blood for histamine level. These can be costly, though. So I would always suggest using a food diary first. In which case, if you suspect histamine intolerance, an elimination diet can also be useful, whilst you are addressing root causes.
Sauerkraut is a brilliantly nourishing, gut healthy food. But is very high in histamine. One of the clearest signs of histamine intolerance is a bad reaction to having fermented foods such as
as sauerkraut.
What can be done to help my child?
Remove problem foods
Studies have shown success with elimination diets for diagnosing and treating histamine intolerance. An elimination diet is a diet eliminating all foods high in histamine.
You will eliminate all histamine foods from the child's diet for a certain period of time - usually between 1-3 months. Avoiding all histamine rich foods.
During this time, you can use a food diary (click here for the one we use) to track progress and see if symptoms improve. If so, you can start to reintroduce foods one at a time and in moderation. This way, you'll be able to see which foods cause symptoms/ can be tolerated and those that cannot.
Try not to eat leftovers that have been sitting around too long (even refrigerated)
This can be tough when you are cooking for your family. But take it back to basics, just cook what you need. Make simpler meals like platters with whole foods that don't require as much cooking. Leftover food can have significant levels of histamine, and the levels will vary depending on how fast this microbial metabolism takes place. It’s important to note that histamine levels can be excessively high well before the food is spoiled, too. Leftovers were a huge issue for us at the start. They are better tolerated since some healing has taken place.
Consumption of certain foods can help to lower histamine by stabilising the mast cells from which histamine can be released.
Foods such as;
Ginger
Turmeric
Thyme
Holy basil
Pomegranate
Tarragon
Pea sprouts
Foods high in quercetin can also help lower histamine levels.
Quercetin is a bioflavonoid found in ginger, garlic, onions, elderberries, bee pollen, and fennel leaves.
Nettle and milk thistle are also known to be helpful in histamine disorders.
Certain probiotics have been found to reduce or produce histamine.
When considering probiotics, it’s important to ensure that supplements contain the right strains. There are certain probiotic strains which have been shown to reduce histamine levels, such as Bifidobacterium Infantis, Bifidobacterium Bifidum, Bifidobacterium Longum, Lactobacillus Salivarius, Lactobacillus Plantarum, Bifidobacterium Lactis, Bifidobacterium Breve, and Lactobacillus Rhamnosus.
Some strains of probiotics actually produce histamine.
Probiotics that produce histamine:
Lactobacillus Reuteri
Lactobacillus Helveticus
Lactobacillus Casei
Lactobacillus Bulcarius
Do your best to ensure adequate intake of vit c, zinc, B6, iron, magnesium and copper, as DAO functioning is dependent on these nutrients being balanced and optimum.
Sources include
Vitamin B6 can be found in salmon, eggs, chicken liver, beef, carrots, spinach, sweet potato, green peas, bananas, chickpeas, and avocados
Copper is found in leafy greens such as Swiss chard, nuts and seeds, shiitake mushrooms and liver
Magnesium is found in pumpkin seeds and leafy greens
Iron can be found in organ meats, legumes, red meat, and pumpkin seeds
Vitamin C can be found in all fruits and vegetables, particularly in kiwifruit, oranges, and berries.
Improving underlying bacterial imbalances and gut health.
Eat a diverse variety of plants - aim for different per week
Reduce toxins
Sleep
Focus on reducing foods which exacerbate the growth of unwanted bacteria, such as processed foods and refined carbohydrates
Use bacterial repelling herbs such as garlic, rosemary, oregano, and olive leaf
Lower protein diet
Many parents on a healing journey resort to diets extremely high in protein. From my own observations in my own child, this has been disastrous from a histamine perspective.
Histamine is mainly made from histidine, which is an amino acid. Since amino acids like histidine are derived from protein, it is logical that foods high in protein can impact histamine levels. This is especially the case with food protein that cannot be easily digested in the gut, since the levels of histamine are known to increase as the food is digested. Because it is digested slowly and is left to age in the gut, this feeds bacteria and can also increase histamine also. This can be one of the reasons why the GAPS diet might not be successful for some.
AVOID UV LIGHTING
UV light triggers the release of histamine. If you suspect your child already has histamine intolerance, exposure to UV light could exacerbate the problem.
Many of the sensory toys aimed at children are fitted with UV light.
Sources and Further Reading
