Is it just hay fever, or could it be something else?
Spring in Christchurch brings longer days, beautiful blossoms… but for many of us, the familiar sneezing, itchy eyes and runny nose that come with pollen season!
However histamine isn't just something to associate with hay fever. It's a natural chemical messenger in the body, involved in immune responses, digestion and other important functions.
But what happens when histamine becomes part of a bigger picture involving digestive symptoms, skin reactions, headaches or feeling generally unwell? And could your gut health and genetics be playing a role?
Explaining histamine.
Histamine is produced naturally by our bodies and is also found in certain foods. During an allergic response, immune cells release histamine, contributing to symptoms such as sneezing, itching, watery eyes and a runny nose.
Some people also report symptoms that may be associated with sensitivity to dietary histamine, including flushing, headaches, digestive discomfort, diarrhoea (or very soft bowel motions) and itchy skin. For example aged cheese, fermented foods, cured meats, alcohol and leftover foods are just some of the common culprits that contribute to histamine symptoms.
However, these symptoms can have many different causes. Seasonal allergies, food allergies, other medical conditions and possible histamine intolerance need to be distinguished rather than assumed to be the same thing.
What does your gut have to do with histamine?
Your gut microbiome is made up of trillions of microorganisms that influence digestion, immune function and the environment within your digestive tract.
Some gut bacteria can produce histamine, while the activity of other bacteria and the health of the intestinal lining may influence how your body responds to different substances.
Your digestive system also plays an important role in breaking down histamine from food. One enzyme involved in this process is diamine oxidase (DAO), which is produced in the intestinal lining.
When digestive health is compromised, it's worth considering whether several factors may be contributing to a person's symptoms. These could include changes in the gut microbiome, intestinal inflammation, food-related triggers or other underlying digestive conditions.
Research has identified differences in gut microbial patterns in some people reporting histamine intolerance, and the evidence is still developing. So we cannot assume that a particular microbiome imbalance causes histamine symptoms, or that correcting one bacterial finding will resolve them. But it can definitely be part of the picture for many. In fact, histamine can be detected on a GUT IQ microbiome stool analysis. But the sole cause may not be due to poor microbiome diversity only.
But, if you are experiencing persistent digestive symptoms alongside skin complaints, headaches or other reactions, it may be worth looking beyond individual foods and considering the wider microbiome picture.
Could your genes influence how you process histamine?
Our genes provide instructions for making the enzymes and proteins involved in many of the body's processes, including histamine metabolism.
Two genes of interest are:
AOC1: provides instructions for producing diamine oxidase (DAO), an enzyme involved in breaking down histamine, particularly in the gut.
HNMT: provides instructions for producing another enzyme that helps break down histamine within cells.
Genetic variations may influence how these pathways function, but they don't tell us on their own whether someone has histamine intolerance or will develop symptoms.
This is where nutrigenomics can be helpful as part of the wider assessment.
Understanding relevant genetic variations may add another piece of information when considered alongside symptoms, medical history, diet and digestive health.
Your genes are part of the picture, but not the whole story!
How can GUT IQ and DNA testing help?
In clinic, I look at health through an individualised, functional nutrition lens. Rather than guessing which foods or supplements might help, the aim is to build a clearer understanding of the factors that may be contributing to your symptoms.
GUT IQ (microbiome stool analysis) provides information about the microorganisms in your gut, alongside other digestive and intestinal markers included in the test. This can help guide questions about microbial balance and digestive function. Although there is a histamine panel, this does not diagnose histamine intolerance or establish which gut bacteria are responsible for allergy symptoms. But can help to validate the presenting symptoms, and allow this to be part of the treatment focus.
Smart DNA nutrigenomics testing can provide information about selected genetic variations involved in processes such as histamine metabolism. These findings can help inform individualised nutrition requirements, but genetic results need to be interpreted cautiously and alongside your clinical picture.
Neither test is necessary for everyone, and neither replaces appropriate medical assessment for allergies or other conditions. Depending on your symptoms, a different investigation or referral may be more useful.
Where should you start?
If spring allergies are causing you concern and you also experience ongoing bloating, bowel changes, unexplained skin symptoms, headaches or reactions to a wide range of foods, it may be worth investigating further using functional testing.
In the meantime, focus on a varied, nourishing diet that supports your overall health. Avoid jumping into a long list of food exclusions or a restrictive low-histamine diet without a clear reason, as this can make eating unnecessarily complicated.
At Nutri Viva, I help clients look beyond individual symptoms to explore the connections between digestion, the microbiome, nutrition and metabolic health. When appropriate, functional testing can help guide that process.
If you're curious about whether your gut health or genetics could be relevant to your own health concerns, make sure to reach out!
Blog image, photo by Simon Kadula on Unsplash