In brief
Nutrigenomics uses a DNA cheek swab to look at 36 metabolic and biochemical pathways, including the DAO (diamine oxidase) and HNMT (histamine N-methyltransferase) genes involved in histamine breakdown. Your DNA stays the same for life, and gene expression changes with your nervous system, food, sleep and stress. I read the genetic results alongside your symptoms and history to personalise your plan, and genetic testing is optional. A genetic test you order on your own gives you basic information. Testing with me gives you more detailed, specific information, because a well-trained practitioner is needed to interpret the results fully.
You have followed the low histamine food list. You have tried the supplements that seem to work for everyone else in the social media support groups. Some of the supplements helped a little, some left you reacting more, and nobody could explain why your body responds the way it does.
Nutrigenomics is one way to start understanding why your body responds the way it does. Nutrigenomics looks at how your genes influence the way your body handles food and nutrients, so your plan can be matched to your biology and not to the average woman's. In my practice, nutrigenomics is an optional add-on to the Happy Without Histamine Method and the gut microbiome restoration package. Genetic testing can help provide more information to inform your personalised plan. Most of my clients don't need it, and some clients arrive already with genetic tests. If you're interested in understanding your genetics and how that can relate to your symptoms, then genetic testing is available for you.
Does any of this sound like you?
- You have worked through most of the low histamine and gut advice, and the results do not match the effort you have put in
- A supplement that has been recommended works for everyone else but it sets you back
- Coffee, tea or chocolate leaves you wired, flushed or unable to sleep, even in small amounts
- Your reactions do not follow the rules on the food lists
- You are tired of trial and error and want a clearer place to start
- You want a plan built around your own biology, not the average woman's
If that sounds familiar, I understand. I was down to five foods, unable to take supplements and still reacting, so I know how it feels when standard advice does not fit your body. Genetic information will not answer every question, but it can take some of the guesswork out of deciding where to start.
What is nutrigenomics?
Nutrigenomics is the study of how your genes influence the way your body responds to food and nutrients. Genes are the instructions written in your DNA. A single nucleotide polymorphism (SNP, pronounced “snip”) is a single spelling change inside one of those gene instructions, and one spelling change can make an enzyme work faster, slower or differently. Most of your DNA is the same as everyone else's, and the small differences are where the personal detail sits.
The 3x4 Genetics test is a simple cheek swab. The 3x4 Genetics report looks at 36 metabolic and biochemical pathways, and groups many SNPs together within each pathway instead of reading one gene in isolation (3x4 Genetics). A single SNP rarely tells the full story, so I base decisions on the pattern across a pathway and your detailed health history. Not every SNP has strong supporting research either, so I never build a plan in isolation.
What is epigenetics, and what can change gene expression?
The code in your DNA stays the same for life. Gene expression, meaning how strongly each gene gets switched on or off, changes with your nervous system, your food, your sleep, your exposure to toxins and your stress load. The layer that controls gene expression is called epigenetics, and epigenetics is where we get to work!
Think of your genes as a recipe, and your nervous system, food and environment as the kitchen where the recipe gets cooked. The same recipe turns out differently in a calm, well-stocked kitchen than in a chaotic one.
“With epigenetics, we know you can have a genetic SNP which may influence health, but you also need something to pull the trigger, and that's a combination of diet, gut health, chronic stress and the environment. If we regulate the nervous system, we actually improve the epigenetic outcome.”
- Luanne Hopkinson, Clinical Nutritionist and Nervous System Coach, 3x4 Genetics practitioner, Melbourne, Australia
Because of epigenetics, I pair genetic results with nervous system regulation. A nervous system stuck in threat sends stress signals through the gut and the immune system, including the mast cells, so stress can be the very thing that pulls the trigger on a genetic variant. Genetic results guide me on areas to support, and nervous system regulation changes the conditions the genes are working in.
How daily life changes gene expression
Epigenetics, made visible
Your genes are the instructions. Your nervous system, lifestyle and diet control the dimmer switches.
Epigenetics means “above the genes”. Move the five dimmers below and watch how the same genes can send a bigger or smaller clean-up crew to tidy up the histamine after the party.
Is the histamine clean-up crew on shift?
The dark line marks the baseline, or starting level
Getting busy
Step 1: choose the genes
A histamine-rich meal is like a party, and DAO and HNMT are the clean-up crew that tidies the histamine away afterwards. Each gene holds the instructions for making one of the crew’s enzymes. Some women carry a variant (a SNP) in these genes that makes the enzyme work more slowly. Try both.
Step 2: turn the dimmers
Nervous system
Improving
A nervous system that is part way to settled lets digestion start working again, so more nutrients reach the gut lining. The body can also make more DAO and HNMT, so more of the crew turns up.
Food and nutrients
Improving
A food list that is widening gives the body more of the nutrients needed to make DAO and HNMT.
Gut health
Improving
A gut lining that is settling gives the DAO-making cells better conditions.
Sleep
Improving
Sleep that is improving gives the stress response more time to reset each night.
Environment
Improving
Reducing the biggest exposures leaves the body less to clear.
The instructions stay the same. The five areas we can influence are where we work together.
Your DNA does not change, and a variant only lowers the baseline, and does not mean there is no room for improvement. Nervous system, food, gut, sleep and environment all influence the expression of the gene, which is why the genes are not the end of the story.
Nutrigenomics adds the next layer. A genetic test shows which of your genes, such as DAO, HNMT, COMT (catechol-O-methyltransferase) or MTHFR (methylenetetrahydrofolate reductase), are the best focus of support, so the dimmers we turn first are chosen for your biology and not for the average woman.
This illustration explains the idea of epigenetics. The movement shown is not a measurement, a diagnosis or a prediction. Epigenetic research is still developing, and responses differ from person to person.
Concept reference: 3x4 Genetics, Genetic Principles (epigenetics means “above the genes”).
What can genetic testing show for histamine intolerance and MCAS?
The four examples below come from the pathways I look at most often with women who have histamine intolerance, mast cell activation syndrome (MCAS) and gut symptoms. Each result points to where support is likely to be most useful, and no single result is a verdict.
CYP1A2 gene
Coffee and caffeine
CYP1A2 is a liver enzyme that breaks down caffeine. Some women may clear caffeine quickly and enjoy a morning coffee without trouble. Other women may clear caffeine more slowly, so one coffee may keep the stress response switched on for hours, with a racing heart, restless sleep and a nervous system that stays on alert.
Research on CYP1A2 and caffeine response is mixed, so your CYP1A2 result is one piece of the picture, alongside how coffee feels in your body. Your result gives us a starting point for coffee, tea and chocolate instead of a blanket rule.
In my 20s, I used to drink a lot of coffee, and I wondered why I felt more stressed out with a racing heart when other people did not. Now, after doing my genetics, I understand why. Caffeine is not my friend.
COMT gene
Quercetin and COMT
Quercetin is a plant compound that many women with MCAS and histamine intolerance consider for mast cell support. COMT is an enzyme that helps clear stress chemicals such as adrenaline and dopamine, and some plant compounds.
Research on COMT and quercetin is still limited, so I introduce quercetin gradually and watch how your body responds. Your COMT results are one piece of the picture, alongside your symptoms, your history and how you respond to each new supplement.
DAO and HNMT genes
Histamine breakdown
Your body breaks histamine down in two main places. The DAO enzyme (made from the AOC1 gene) clears histamine from food in the gut. The HNMT enzyme clears histamine inside cells, including cells in the brain and nervous system.
After a histamine-rich meal, DAO and HNMT work like a clean-up crew after a party. Each gene holds the instructions for making one of the crew's enzymes, and a variant can mean a smaller or slower crew.
Variants in either gene can change how much clearing capacity you have. Genetic results help show which route needs the most support, and the results guide which foods we focus on and where nutrient support goes. Stress adds to the load, because stress hormones can prompt mast cells to release more histamine, so a stressed nervous system hands both enzymes more histamine to clear.
MTHFR and related genes
Methylation
Methylation is a chemical process inside every cell. Methylation supplies the methyl groups that HNMT relies on to clear histamine, and MTHFR is one of the genes involved in the wider methylation cycle. An MTHFR result on its own cannot tell us how well HNMT is working.
A variant in MTHFR does not decide your outcome. B vitamins, protein, sleep and stress load all influence how well methylation runs, and my position is that nervous system regulation can improve gene expression even when a variant is present.
None of these results is a diagnosis. I read genetic results alongside your symptoms, your history and your lab results, and then we use the results to decide where support goes first.
What does the 3x4 Genetics report cover?
The 3x4 Genetics report covers 36 pathways in six categories. Because the report is broad, I focus on the pathways that matter most for your symptoms, your history and your goals.
Cellular
Methylation, inflammation, oxidative stress, detoxification
Systems
Histamine overload (DAO and HNMT genes), collagen and joints, glucose and insulin, memory and brain health, bone health, mood and behaviour, hormone balance
Cardiovascular health
Vascular health, blood pressure, blood clotting, cholesterol
Energy
Pro-inflammatory fat, adipogenesis, weight gain and weight loss resistance, exercise response, energy expenditure, appetite, satiety and intake
Activity
Injury, endurance, recovery, power, training response
Nutrients
Vitamin B12, choline, folate, salt, vitamin D, caffeine, fatty acids, gluten, iron overload, vitamin C
What is included in genetic testing with me?
The Happy Without Histamine Method follows the 5R Histamine Modulation Protocol™, five phases in this order: Relieve, Regulate, Repair, Restore and Reintroduce. Genetic results can add personal detail to every phase: which foods we start with in Relieve and expand to in Reintroduce, which nutrients and plant compounds suit you in Repair and Restore, and where nervous system work needs the most attention in Regulate.
Genetic testing is an optional add-on to the HWH Method and the gut microbiome restoration package, where genetic results, microbiome results and nervous system work are read together to personalise your plan.
Pricing differs between countries, and you'll be advised at the time how much it will cost if you choose to do this test. The test fee covers the test kit and the lab report, and results sessions are included when you work with me in the Happy Without Histamine Method or the gut microbiome restoration package.
What you receive
- A cheek swab test from 3x4 Genetics, covering 36 metabolic and biochemical pathways
- Your results explained in plain language, alongside your symptoms, history and any lab results
- Food, nutrient and lifestyle choices matched to your pathways
- Nervous system work running alongside, so your genes are working in the best conditions we can create
“Nutrigenomics is a way that we can give our genes the best possible support with food and supplementation. When we work with our nervous system as well, we are shifting our body into the right environment for the most optimal gene expression.”
- Luanne Hopkinson, Clinical Nutritionist and Nervous System Coach, 3x4 Genetics practitioner, Melbourne, Australia
Genetic testing is a once-in-a-lifetime investment
Your DNA does not change, so a full genetic test needs to be done only once. Your gene expression does change, and gene expression is where we work together. The same results stay useful as your gut, your diet, your stress load and your life change, because genetic results describe your biochemical wiring, not only your current symptoms. Genetic testing is therefore a one-time investment that keeps informing your plan.
Genetic testing is optional
You do not need genetic testing to work with me, and plenty of women work with me without genetic testing. I offer genetic testing as an extra for women who have tried the standard approaches and feel the plan needs more personal detail, for women who are curious about their own biology, and for women whose reactions do not follow the usual patterns.
I am a 3x4 Genetics practitioner in Melbourne, Australia. I completed training in the Fundamentals of Nutrigenomics, achieved the 3x4 Blueprint Certification and am a member of the 3x4 Practitioner Network. I use 3x4 Genetics for genetic testing.
I work with clients online in Australia, New Zealand, the United Kingdom, Europe and the USA. Genetic testing is ordered through 3x4 Genetics regional distributors, and some countries cannot order the test, so check availability with me before booking.
Frequently asked questions about nutrigenomics and genetic testing
What is nutrigenomics?
Nutrigenomics is the study of how your genes influence the way your body responds to food, nutrients and plant compounds. In my practice, nutrigenomics means using the results of a 3x4 Genetics test to personalise nutrition and nervous system support for histamine intolerance, mast cell activation syndrome (MCAS) and gut symptoms.
If my genes cannot change, why get a genetic test?
Your DNA code stays the same for life, but your gene expression does not. Gene expression responds to your nervous system, food, sleep, stress and environment, which is the field of epigenetics. A genetic test shows where your genes are likely to need the most support, and then we work on the conditions that shape gene expression.
Do I need genetic testing to work with you?
No. Genetic testing is optional, and the Happy Without Histamine Method does not require genetic testing. I offer genetic testing as an extra for women who have tried everything and want more personal detail in their plan.
Can I order a genetic test myself?
Some genetic tests can be ordered directly, and a test ordered on your own gives you basic information. Testing with me gives you more detailed, specific information, because a well-trained practitioner is needed to interpret a full report alongside your symptoms, history and lab results. In Australia, the 3x4 Genetics test is ordered through a practitioner.
How much does genetic testing cost?
Pricing differs between countries, and you'll be advised at the time how much it will cost if you choose to do this test. The test fee covers the test kit and the lab report, and results sessions are included when you work with me in the Happy Without Histamine Method or the gut microbiome restoration package.
Who is genetic testing most useful for?
Genetic testing tends to be most useful for women who have already tried the standard low histamine and gut approaches and are still stuck, women who react to supplements or plant compounds and don't know why, and women who want to understand their own biology. Some women find genetic results explain patterns noticed for years.
Can genetic testing diagnose histamine intolerance or MCAS?
No. Genetic testing does not diagnose histamine intolerance or mast cell activation syndrome (MCAS). Genetic results show how your body is wired to handle things like histamine, gluten, exercise, diet and caffeine, while your symptoms, history and lab results show what is happening right now. I read genetic results, symptoms, history and lab results together.
Does a DAO variant mean I have histamine intolerance?
No. A variant in the AOC1 gene, which holds the instructions for making the DAO (diamine oxidase) enzyme, describes how the enzyme may work, and a variant does not diagnose histamine intolerance. I read genetic results alongside your symptoms, history and lab results, because your nervous system, gut, food and stress load all influence how much histamine your body clears.
Does nutrigenomics test for genetic conditions such as Down's syndrome?
No. Nutrigenomics looks at common gene variants, called single nucleotide polymorphisms (SNPs), that influence how your body handles food and nutrients. Nutrigenomics does not test for chromosomal or inherited genetic conditions such as Down's syndrome, and nutrigenomics does not replace medical genetic testing. Your GP can refer you to a genetic counsellor for those questions.
If I carry a variant such as MTHFR or COMT, am I stuck with the variant?
No. A variant in a gene such as MTHFR (methylenetetrahydrofolate reductase) or COMT (catechol-O-methyltransferase) influences how an enzyme works, and a variant does not decide your outcome alone. Nutrients, sleep, stress load and the state of your nervous system all shape gene expression, so a variant points to where extra support is likely to help.
What happens after I do the genetic test?
I go through your results with you in plain language, alongside your symptoms, history and any lab results. We then use the pathways that stand out to personalise food, nutrient and lifestyle choices inside your plan, with nervous system work running alongside.
How is my genetic information kept private?
3x4 Genetics stores genetic information on encrypted cloud servers, separate from your identifying details, and the laboratory destroys your DNA sample after 6 months. 3x4 Genetics may process samples and data in other countries, and may use de-identified, combined data for research. When I receive your results, I keep your results in HIPAA-compliant systems and handle your results in line with the Australian Privacy Principles. Full details are in the 3x4 Genetics privacy policy and my privacy policy.
Add genetic detail to your plan
Genetic testing is an optional add-on to the HWH Method and the gut microbiome restoration package, and you can ask me about genetic testing whichever way you start.
Related conditions
Services and programs
What the research shows, and where the limits are
Nutrigenomics explores how food, lifestyle, gut microbial activity, stress, sleep and environment may influence gene expression and biochemical pathways. Variants in genes such as AOC1, HNMT, COMT, CYP1A2 and MTHFR may contribute to individual differences, but current research does not support using a single SNP to diagnose histamine intolerance or mast cell activation syndrome, to predict symptoms, or to prescribe the same supplement protocol for everyone. I use genetic results as one part of the picture, alongside your symptoms, history and lab results.
Sources
- Maintz L, et al. (2011). Association of single nucleotide polymorphisms in the diamine oxidase gene with diamine oxidase serum activities. Allergy. Case-control genetic study: AOC1 variants influence DAO enzyme activity, and genetics alone do not determine symptoms.
- Jochum C. (2024). Histamine intolerance: symptoms, diagnosis, and beyond. Nutrients 16(8). Review: histamine intolerance reflects histamine building up when the capacity to break histamine down is exceeded.
- Duelo A, et al. (2024). Pilot study on the prevalence of diamine oxidase gene variants in patients with symptoms of histamine intolerance. Nutrients 16(8):1142. Retrospective pilot study: counting AOC1 variants alone may not be enough to diagnose histamine intolerance.
- Alemany-Fornés M, et al. (2025). Diamine oxidase deficiency: implications for health, current management, and future directions in the treatment of histamine intolerance: a review. International Journal of Biological Macromolecules 327:147130. Review: low DAO activity, and the genetic and dietary factors that affect DAO activity.
- Yoshikawa T, et al. (2019). Histamine N-methyltransferase in the brain. International Journal of Molecular Sciences 20(3):737. Review: HNMT breaks down histamine in the brain.
- Fenech M, et al. (2011). Nutrigenetics and nutrigenomics: viewpoints on the current status and applications in nutrition research and practice. Journal of Nutrigenetics and Nutrigenomics 4(2):69-89. Review: diet can influence gene expression, including through epigenetic changes such as DNA methylation. The authors also caution that genotype-based dietary advice still needs more validation.
- Theoharides TC, Stewart JM. (2015). Genitourinary mast cells and survival. Translational Andrology and Urology 4(5):579-586. Narrative review: emotional stress is a common symptom trigger in systemic mastocytosis, and corticotropin-releasing hormone can activate mast cells.
- Virgili J, et al. (2023). The impact of genetic variability on the relationship between caffeine and cardiometabolic outcomes: a systematic review. Nutrition Bulletin. Systematic review of how genetic variants relate to caffeine and cardiometabolic outcomes.
- Clark I, Landolt HP. (2017). Coffee, caffeine, and sleep: a systematic review of epidemiological studies and randomized controlled trials. Sleep Medicine Reviews 31:70-78. Systematic review of studies on coffee, caffeine and sleep.
Sources checked October 2026.
Nutrigenomics looks at common gene variants (SNPs) that influence how the body handles food and nutrients. Nutrigenomics is not a diagnostic test and is not suitable for investigating inherited or chromosomal genetic conditions, such as Down's syndrome. Anyone with concerns about a genetic condition, or a family history of one, should speak with a GP or genetic counsellor. Genetic testing does not replace medical care.
