The Vicious Cycle Driving Pre-Menstrual Anxiety, Indigestion, Headaches, and More
More and more women are presenting in clinical practice with undiagnosed histamine intolerance. The key to understanding what drives it is to examine its relationship with the hormone oestrogen – and how the two feed each other in a cycle that can be difficult to break without the right approach.
Many of the women I work with have already been through the rounds of conventional testing and treatment with their GP, without uncovering any significant reason for their intense symptoms. Anxiety, congestion, headaches, PMS, pain, and indigestion that seem to be significantly worse around ovulation and premenstrually are extremely common in this group.
Supplements, herbs, and pain medications may be providing some relief – but they’re not getting to the root cause. If this sounds familiar, histamine intolerance may be the missing piece.
What Is Histamine Intolerance?
Histamine intolerance occurs when there is a build-up of histamine in the body due to an impaired ability to handle, break down, and metabolise the histamine we produce internally and consume through food. When histamine accumulates because we’re not clearing it efficiently, symptoms of intolerance begin to emerge.
A useful way to understand this is the “bucket” analogy. Under optimal conditions, the body metabolises and clears both dietary and endogenous histamine with ease. But when the bucket overflows – because we’re not emptying it fast enough – symptoms appear.
Histamine intolerance is one of many food chemical intolerances that can produce an all-over-the-place symptom picture, where it seems impossible to identify which foods are responsible. This is because histamine is present in so many foods that complete avoidance is almost impossible without addressing the underlying cause.
Classic Symptoms of Histamine Intolerance
- Gut symptoms – altered bowel function, abdominal pain, nausea, cramping, reflux
- Headaches and migraines
- Heavy and/or painful periods
- Joint pain
- Tissue swelling
- Hives, flushing, skin rashes
- Brain fog, anxiety, depression
- Respiratory symptoms – congestion, runny nose, sneezing, difficulty breathing
What Does Oestrogen Have to Do With It?
The majority of people who develop histamine intolerance are women, and this appears to be closely linked to the hormone oestrogen.
A significant clue that histamine intolerance may be involved is if symptoms such as headaches or migraines, anxiety, and gut issues are consistently worse in the lead-up to ovulation and premenstrually.
This is because oestrogen rises sharply before ovulation, and remains relatively higher than progesterone in the premenstrual phase as progesterone naturally declines (demonstrated in the graph below). As oestrogen rises through these phases of the cycle, histamine levels follow – because the two actively stimulate each other.
It is also common for women to begin experiencing these symptoms during perimenopause and menopause. Although oestrogen levels eventually decline, it is progesterone that drops first – meaning oestrogen remains relatively elevated long enough to perpetuate the histamine-oestrogen cycle.
Interestingly, histamine intolerance symptoms often improve during pregnancy, as the placenta dramatically increases production of the DAO enzyme – the enzyme responsible for breaking down histamine.
Oestrogen, particularly the oestradiol form, has been shown in numerous studies to activate mast cells – the cells most responsible for releasing histamine into the bloodstream when triggered by the immune system.
The result is a self-reinforcing cycle:
↑ Oestrogen → ↑ Histamine release → ↑ Oestrogen production → Chronic symptoms continue
This connection is also explored in the context of PCOS and oestrogen-related hormonal imbalances, where the same cycle plays out in different clinical presentations.
As you can see in the picture, below, once histamine is released it has the potential to cause a large number of symptoms due to its effect on vasodilation, neurotransmitter release, mucous secretion, oestrogen production, smooth muscle contraction & gastric acid secretion.
The Key to Overcoming Histamine Intolerance – Treating the Gut
The most commonly cited cause of histamine intolerance is a deficiency in diamine oxidase (DAO), the enzyme responsible for breaking down histamine. Many people seek out DAO supplements as a solution – but this is an expensive approach that doesn’t address the true underlying cause.
DAO is produced by the lining of the intestine. This is a clear sign that damage to the gut wall is a central driver of histamine intolerance – an indirect consequence of gut dysbiosis (microbial imbalance).
Gut dysbiosis also directly increases histamine levels by driving over-activation of the immune system. To treat that immune activation, you must address the dysbiosis itself. There is also a well-documented link between altered histamine receptor expression and Irritable Bowel Syndrome (IBS), where dysbiosis is a key underlying factor. You can read more about this connection here.
A common downstream effect of chronic dysbiosis is Small Intestinal Bacterial Overgrowth (SIBO), which is very frequently seen alongside histamine intolerance. Depending on symptoms, SIBO may need to be ruled out and addressed as part of treatment. You can learn more about leaky gut and its role in chronic conditions here.
What to Do If You Think You May Have Histamine Intolerance
- Track your menstrual cycle – because histamine rises and falls with oestrogen, tracking your cycle to see whether symptoms intensify around ovulation and premenstrually is a simple and informative starting point
- Trial a lower histamine diet – histamine is present in most foods to some degree, so it’s more about reducing total load than achieving complete avoidance. If you have true histamine intolerance, some level of improvement should be noticeable within two to three weeks
- Rule out underlying conditions – coeliac disease, inflammatory bowel disease, lactose intolerance, and SIBO can all contribute to or mimic histamine intolerance. Histamine intolerance is ultimately a symptom of a deeper issue rooted in gut health
- Check your medications – antidepressants, antipsychotics, blood pressure medications, antibiotics, diuretics, muscle relaxants, and antimalarials can all interfere with adequate DAO enzyme production. Do not stop any medication without discussing this with your medical team
Low-Histamine Diet Guide
A low-histamine diet is a useful starting point. If you have true histamine intolerance, the relief is often rapid and noticeable – even if only partial.
High-Histamine Foods to Reduce or Avoid
- Fruits – citrus, bananas, papaya, pineapple, strawberries, dried fruits
- Vegetables – avocados, eggplant, spinach, tomatoes, sauerkraut and other fermented vegetables
- Nuts – all nuts and peanuts
- Dairy – all dairy products including fermented dairy such as yoghurt and kefir
- Dairy alternatives – coconut yoghurt and other fermented products
- Protein – cured meats, shellfish, mackerel, tuna, smoked fish, anchovies, sardines
- Starches – soured breads, wheat germ
- Seasonings and condiments – pickles, olives, vinegars, miso, soy sauce, tamari, mayonnaise, artificial preservatives and dyes
- Drinks and alcohol – wine, champagne, beer, kombucha, energy drinks, black and green tea, yerba mate
- Chocolate
Lower-Histamine Foods to Focus On
- Fruits – all fresh fruits except citrus, banana, papaya, pineapple, and strawberries
- Vegetables – all fresh vegetables except avocados, eggplant, spinach, and tomatoes
- Dairy alternatives – coconut milk, rice milk, hemp milk, almond milk
- Protein – freshly cooked meat and poultry (frozen or fresh), freshly caught fish, eggs
- Fats – coconut oil, olive oil
- Seasonings – fresh leafy herbs
- Drinks – herbal teas (no green or black tea; no alcohol)
Freshness matters – many of the foods to avoid are aged or fermented. Avoid leftover meats and fish, and strictly avoid canned fish.
Taking Action
Start by tracking your menstrual cycle, trialling a lower-histamine diet, and seeking the right support to investigate and heal underlying gut dysbiosis and intestinal permeability. With the right approach, histamine intolerance does not have to be a permanent state.
