A nutritionist’s guide to a low-histamine diet

What is histamine?

Histamine is a chemical compound that occurs naturally in the body. When your body detects a threat, it releases histamine to protect your cells.

For people with allergies, histamine is released when an allergen (pollen, dust or pet dander) is detected. While its primary role is to cushion and protect your cells, it also causes inflammation - which leads to allergy symptoms.

Histamine can also be found in many of the things we eat. When we consume histamine-rich foods, the level of histamine in our bodies increases. This can worsen the body’s response to allergens such as pollen, and make hay fever symptoms more noticeable.

What is a low-histamine diet?

A low-histamine diet involves reducing or eliminating foods that are high in histamine. Many different foods contain histamine, but the most important foods to avoid include:

• tinned fish (tuna, sardines, mackerel)
• hard, matured cheeses (parmesan, grana padana)
• smoked or cured meats (salami, prosciutto)
• alcohol
• pickled or fermented foods

Histamine builds up in foods over time, so it’s best to avoid tinned or preserved products and cook with fresh ingredients. It is best to cook from fresh every day if you can make this possible.

What are the benefits of a low-histamine diet?

Following a low-histamine diet can naturally prevent hay fever or allergy symptoms without a need to take medicines.

There is scientific research to support this. In a study that observed the effects of a low-histamine diet on an allergic skin condition known as hives, results showed that:

After a period of three weeks, significant improvements were noticed after the elimination of histamine-rich foods.

For those who are unable to take allergy medicines or have hay fever during pregnancy, it is possible to prevent allergies with diet changes alone.

For hay fever sufferers, this diet only needs to be followed shortly before and during the pollen season. It doesn’t need to be a permanent change.

Which foods should be avoided?

The most important foods to avoid are tinned products, aged meats, hard cheeses and alcoholic drinks.

However, the following table outlines a more extensive list of histamine-rich foods as well as foods that liberate the action of histamine.

You may also wish to avoid pre-packaged foods containing additives such as:

• benzoate
• sulphites
• nitrites
• glutamate
• food dyes

Please note: There is no precise agreement on which foods should be included in this list as the histamine content may vary according to country or region.

Which foods should be included?

When following a low-histamine diet, the following foods are optimal choices:

• fresh or frozen meat
• fresh or frozen white fish
• eggs
• mozzarella and ricotta cheese
• gluten-free grains such as rice and quinoa
• vegetables including broccoli, asparagus, cauliflower, artichokes, beansprouts, carrots, celery, courgettes, cucumber, fennel, onions, parsnips, squash, watercress
• nuts and seeds including almonds, brazil nuts, macadamia nuts, chia seeds, hemp seeds, pumpkin seeds, pine nuts, pistachios, sesame seeds

Nettle tea might also be beneficial as it contains anti-inflammatory properties which may be useful in lowering histamine levels.

Drinking plenty of water also helps to stop histamine from building up in the body.

Low-histamine meal plan

If you’re not sure where to start, our nutritionist has crafted a low-histamine meal plan that’s quick and easy to follow.

Top tips

If you’re feeling unsure about how to follow a low-histamine diet, our nutritionist has also devised a list of top tips.

Shopping tips

When shopping for low-histamine foods, remember these 5 principles:

1. Shop for fresh, whole, unprocessed foods
2. Cook from scratch
3. Avoid foods that have been preserved (as these contain high levels of histamine)
4. How you store and cook foods affects the histamine content
5. If you have leftovers, freeze them instead of refrigerating

Eating out tips

When following a particular diet, you might feel limited in social situations or while eating out. However, you don’t have to miss out just because you’ve changed your eating habits.

1. Plan ahead: When deciding on a restaurant, opt for somewhere that accommodates allergies.
2. Check the menu beforehand: Check to see if there are low-histamine options to avoid a stressful situation.
3. Look at starters and side dishes: If the main dishes aren’t suitable, you could order multiple small plates instead.
4. Ask for advice and substitutes: Asking the waiter to substitute something that’s high in histamine can be a quick fix for staying on track.
5. Check the vegan/vegetarian options: Sometimes these offer the best low-histamine options. Just remember to avoid histamine-rich veggies like tomato, avocado, mushrooms and aubergines.
6. Take a list of foods to avoid with you: It can be easy to get overwhelmed when you first start this diet. Bringing a food list can act as a helpful reminder of which foods you should be avoiding.

How long should I follow a low-histamine diet?

Research has shown that it’s beneficial to follow a low-histamine diet for 4 weeks to see an improvement in your symptoms.

After this, you can slowly start to reintroduce high-histamine foods to help pinpoint foods that are clear triggers.

Exclude these ‘trigger’ foods from your diet throughout the pollen season. Once it reaches autumn, you can return to your usual eating habits.

If you still find you’re suffering from hay fever after 4 weeks of following a low-histamine diet, you may require over-the-counter or prescription treatments to help ease your symptoms.