Histamine intolerance: Could your digestive function play a role?

Have you ever experienced unexplained symptoms like migraines, skin irritation, or gastrointestinal issues after consuming certain foods? If so, you may be suffering from histamine intolerance. 

What is histamine intolerance?

Histamine intolerance occurs when your body is unable to effectively break down and eliminate histamine, leading to a buildup of this compound in your system. Understanding the role of amines and histamines in our diet and improving digestion and anything else that is amiss can help alleviate the symptoms associated with histamine intolerance.

Histamines, a type of amine, are widely known for their association with allergies and hay fever, often requiring antihistamines for relief. However, histamines are also present in various foods, and when consumed in excess, can lead to long-term health issues.

Symptoms of histamine intolerance

• inflammation
• skin irritation
• diarrhoea
• headaches

Additionally, amines can trigger a range of physical and behavioural symptoms, including:

• migraines
• dizziness
• nausea
• acid reflux
• irritated or itchy skin
• trouble falling asleep
• facial flushing
• gastrointestinal cramps

When histamine levels in the body exceed the capacity to break them down, symptoms of histamine intolerance can arise. This intolerance can be caused by various factors, including impaired production or activity of the enzymes responsible for breaking down histamine, such as diamine oxidase (DAO) or histamine N-methyltransferase (HNMT). Additionally, certain medications, gut dysbiosis, and intestinal permeability issues can contribute to histamine intolerance.

When I see clients in clinic with suspected histamine intolerance, I look at a number of factors - symptoms, anti-histamine usage, diet and digestive function as histamine receptors are found in the GI tract - in order to fix their symptoms so that they can stop feeling so unwell. 

Strategies to manage histamine intolerance

Improving digestion plays a crucial role in addressing histamine intolerance but there are some additional strategies that can also help:

1. Identify and avoid high-histamine foods

Keep a food diary to track your symptoms and identify any patterns between certain foods and your symptoms. 

Foods high in histamine include:

• avocados
• bananas
• tomatoes
• aged cheese
• chocolate
• fermented products
• processed meat
• alcohol
• fish products
• yeast extracts

Limiting or eliminating these foods from your diet can help reduce histamine intake. Below is a list of some of the foods you can eat:

• Gluten-free grains like amaranth, arrowroot, buckwheat, millet, rice, quinoa, and more.
• Fresh meat that has not been aged. 
• Salmon - only fresh or flash-frozen within 30 minutes of catch.
• Non-citrus fruits like apples, blueberries, mangoes, peaches, pomegranates, and more. Avoid grapefruit, lemon, lime, and orange. 
• Non-dairy milk like almond, coconut, or hemp.
• Fresh vegetables; avoid tomato, avocado, eggplant, squash, and spinach.
• Olive oil.
• If you tolerate milk: butter, ghee, cream, cream cheese, ricotta, mozzarella, and other soft cheeses that have not been aged or fermented.

However, it can be a tricky diet to follow as it cuts out so many otherwise healthy foods and I have helped other clients with histamine issues without having to put them onto a restrictive diet. 

2. Enhance DAO activity

DAO is the enzyme responsible for breaking down histamine in the gut. Certain nutrients like vitamin B6, vitamin C, copper, and magnesium are necessary for DAO activity. Including foods rich in these nutrients, such as leafy greens, citrus fruits, nuts, and seeds, can help support DAO function.

3. Address underlying gut issues

If you suspect gut dysbiosis or intestinal permeability issues, it's essential to address these underlying conditions and I can arrange functional testing for many gut-related issues.

How can a nutrition professional help?

Histamine intolerance can vary from person to person, and the severity of symptoms can differ as well. While the strategies mentioned above can provide relief for many individuals, receiving personalised guidance is often a much better strategy.

When a nutrition professional works with clients with suspected histamine intolerance, they will take a detailed history to see if a true histamine intolerance is likely to be the case (e.g. if certain anti-histamines you have taken to reduce symptoms have made a real histamine intolerance more likely). A professional can also help you cut out and replace high-histamine foods in your diet for a period of time to see if it makes a difference.

Further testing your microbiome can elicit whether or not you have a large number of histamine-producing or mast cell destabilising bacteria that could be added to your histamine load. This information helps produce targeted nutrition and microbiome support, to improve your symptoms and the range of foods you can eat. Furthermore, some specific nutrients can also help detoxify histamine better, so targeted supplement recommendations may be given.