Do you suffer from unexplained headaches, brain fog or anxiety? What about nasal congestion when you don’t have a cold? Do you have digestive issues like constipation, nausea, diarrhea or acid reflux? Does your face flush when you drink red wine? Do you wake in the middle of the night and struggle to get back to sleep?

If you answered yes to any of these questions, then you could be experiencing histamine intolerance.

Histamine intolerance is a bit of a misnomer really.

Here’s why - histamine is released as part of your inflammatory-immune response and therefore essential to your health.

Rather than becoming intolerant to histamine, what happens is that the body accumulates too much and when this occurs your histamine bucket starts to overflow, producing inflammatory symptoms in the body. The table below lists most of them.

 

The Role of Histamine

Histamine is responsible for the following bodily functions:

• as a neurotransmitter (chemical messenger) in the central nervous system
• promotes stomach acid (hydrochloric acid) release to aid digestion
• an inflammatory response mechanism produced by cells during infection, injury or allergens.

What Triggers High Histamine Levels?

Several factors contribute to the body accumulating high levels of histamine, and many relate to deficiency or dysfunction of the following two main enzymes that degrade histamine:

1. HNMT (N-methyltransferase), breaks down histamine on an intracellular level.  It’s expressed in many human tissues, with the highest levels found in the liver and kidneys, but also in the bronchi and trachea.
2. DAO (diamine oxidase) which is the enzyme produced in your kidneys, thymus and the lining of your digestive tract. It’s primary function is to break down histamine in the body from ingested food and drink.

HNMT and DAO’s failure to degrade excess histamine leads to histamine levels rising and subsequently histamine intolerance symptoms that can be difficult to get under control.

These enzymes can be affected for a number of reasons, and the problems relate to both internal and external factors like:

• Gastrointestinal disorders / bacterial imbalances

• Certain drugs inhibit DAO and HNMT
• Mast cell degranulating estrogen (to progesterone) imbalances
• Many foods have high histamine levels and contribute to enzyme dysfunction
• Some foods have the ability to block DAO
• Other foods, like bananas compound the problem further because they have the ability to trigger the release of histamine within the body even if they don’t contain it

The more these enzymes are blocked while histamine production continues and high histamine foods are ingested, the worse the reaction for the individual.

Histamine & Digestive Disorders

Digestive disorders can also result in histamine intolerance 

• Leaky gut syndrome
• Gluten sensitivity
• Candida overgrowth

• Inflammatory bowel disease (IBD)

• Small intestine bacterial overgrowth (SIBO)

Small Intestine Bacterial Overgrowth (SIBO)

Histamine intolerance can often be caused by the overgrowth of bacteria in the small intestine that produce histamine from undigested food. This leads to the overproduction of histamine that can’t be degraded by DAO.

Histamine Intolerance Testing

If you’re wondering how to test for histamine intolerance, the best way is to follow a low histamine diet for 30 days, and then reintroduce higher histamine foods one at a time. If your symptoms reduce or disappear, and reappear after the reintroduction of the high histamine food phase, then you likely have histamine intolerance.

8 Low Histamine Diet & Wellness Tips

 

1. Commit to a Low Histamine Diet for 30 Days

There’s lots of conflicting low histamine diet lists available online, but basically you want to focus on including and avoiding the foods below when following a low histamine diet.

Of course, everybody is different and there’ll always be personal triggers. If you think certain foods could be an issue then they probably are, whether it’s linked to histamine or not.

Nailing the perfect low histamine diet is not the aim. Use this list as a guide to work out your own low histamine diet and make sure your meals are nutritionally balanced. Because your body also needs proper nutrients to degrade histamine and stay healthy.

Low Histamine Diet Foods

For a low-histamine diet focus primarily on these foods:

• Almonds blanched or with skins
• Coconut milk
• Egg yolk
• Fresh herbs
• Fresh wild-caught fish
• Fresh organic meat
• Fresh vegetables (except ones on the high histamine food list)
• Garlic
• Ginger
• Gluten-free grains (rice, quinoa, buckwheat…)
• Lentils, beans and chickpeas (soaked overnight before cooking)
• Macadamia nuts
• Herbal teas (nettle, chamomile, peppermint)
• Non-citrus fresh fruits

 

2. Avoid High Histamine Foods (during the low histamine diet phase)

These foods could cause an overload of histamine:

• Alcohol
• Avocados
• Bone broth
• Canned food
• Cinnamon, clove and nutmeg
• Most cheeses
• Chocolate
• Fermented food and drinks (kombucha, kefir, kimchi, yogurt, sauerkraut)
• Nuts (especially walnuts and cashews)
• Nightshade vegetables (tomato and all tomato products, aubergine or eggplant, peppers, mushrooms…)
• Processed foods
• Smoked meat and fish products (bacon, salami, ham, salmon)
• Seafood
• Spinach
• Vinegar

 

3. Freeze Leftovers

The longer food sits, the more bacteria grows on it. Leftovers sitting in the fridge can become high in histamine very quickly. Focus on eating fresh foods when at all possible. It’s best to freeze any leftovers that you plan to eat right after cooking in meal-size portions.

 

4. Keep Your Body Hydrated

Histamine is the sensor regulator of water metabolism and its distribution in your body. If your body becomes dehydrated, histamine production will increase as water acts like an antihistamine. Even slight dehydration can elevate histamine and will bring on a thirst response.

 

5. Consume Adequate Amounts of Salt

Salt, also like water, is a natural antihistamine. Many people don’t consume much sodium but it’s important to get enough of the healthy types (sea salt or Himalayan salt, not table salt) especially if you’re struggling with histamine intolerance.

It’s not about drowning your meal in salt. Of course focusing on freshly cooked meals and removing processed foods from your diet is one of the easiest ways to get refined salt out of your diet, which is the stuff you don’t want.

 

6. Support Your Body With DAO

Because histamine build-up can occur as a result of deficient DAO (diamine oxidase) levels, it's crucial to support your DAO levels in order to break down histamine in your body.

First, avoid DAO blocking foods like caffeinated beverages (including green tea) and alcohol. Alcohol always releases histamine from your mast cells but if you develop histamine intolerance, this reaction becomes more prominent.

Foods containing nutrients needed for DAO activity, including vitamin B6, copper, zinc, and anti‑inflammatory fats like omega‑3 fatty acids may help support histamine metabolism.

Just like the low histamine diet, DAO supplements won’t solve the root cause of your histamine intolerance, but they will help to prevent further histamine build-up by removing histamine from the foods and drinks you’re consuming.

 

7. Make Stress Reduction Practices Non-Negotiable

I know you’re probably tired of hearing about stress and the impact on health. The truth is though that working on reducing your stress levels will lower histamine levels and subsequently inflammation allowing your body to heal even more.

Stressors aren’t always obvious either. There can be latent stress within your body that needs addressing like - gut infections and dysbiosis (as mentioned earlier), nutritional deficiencies, hormonal imbalance and compromised immunity.

Stress reduction or management practices should be daily and non-negotiable, rather than reserved for stressful times only. With our modern lifestyle the body is constantly dealing with intrinsic and extrinsic stress - sometimes more, sometimes less.

Without daily down-time for relaxation practices like yoga, meditation, breathing exercises, being in nature, listening to music, playing instruments…it's going to be difficult to degrade histamine and heal your body.

 

8. Promote Hormonal Balance

Estrogen causes mast cells in the body to release histamine. Rising histamine levels cause more estrogen, creating a snowball effect. This is also why you may have experienced more issues with histamine at certain times in your cycle or life – likely when your estrogen levels were higher.

As well as storing and producing histamine your mast cells have estrogen receptor sites. This means that estrogen itself can also cause the production and release of histamine, whereas progesterone naturally lowers histamine levels.

If you’re estrogen dominant (which means you produce more estrogen than progesterone) you probably have higher histamine levels. Estrogen rather unhelpfully also reduces DAO levels adding to the inflammatory fire.

Stress reduction will help with balanced hormones as well as an anti-inflammatory diet. But one of the key things with hormonal imbalance symptoms, like hot flushes, is sleep and vagal tone. Do whatever you can to promote restful sleep at night (which is why it’s important to get histamine under control as this can disrupt sleep and circadian rhythm). My Vagus nerve and Restoring nervous system balance posts offer tips in this area.

Do comment below if you have any histamine intolerance experiences to share that could be helpful for others struggling with histamine intolerance, or if this blog post resonates with you in any way.

 

Nicola x