Are food chemicals to blame for my symptoms?

Food chemicals may sound artificial and even though they are added to some foods, they are also naturally present in many. Food chemicals boast many benefits, such as providing the vitamins and minerals that our bodies require to maintain good health and the delicious flavours and aromas found in our meals.

For some people, these food chemicals can cause adverse reactions, and that is what we call food chemical sensitivity. The three main natural food chemicals that are known to trigger symptoms in those with the sensitivity are salicylates, amines and glutamate.

Natural Food Chemicals

Salicylates are naturally occurring in plants and act as pesticides that protect plants from harmful bacteria and diseases. They are found in many foods including fruits, vegetables, herbs, spices, nuts, jam, honey, tea, coffee, juice and even some alcohols. They can also be found in perfumes, cleaning products and medications.

Amines are produced when proteins are broken down in foods.  They are found in high protein foods such as meat, fish and dairy products as well as fruits & vegetables (especially when ripened), chocolate and many beverages.

Glutamate is a part of proteins and can act as a flavour enhancer. It can be found in many foods including cheese, tomato, commercial sauces and soups, yeast extracts (like vegemite), mushroom and monosodium glutamate (you may have heard of this referred to as MSG).

Many people who are sensitive to these chemicals are also sensitive to food additives, including artificial colours, flavourings and preservatives, as they are structurally quite similar.

Similar to Irritable Bowel Syndrome (IBS), the exact cause of food chemical sensitivity is still being researched, however genetics likely play a large role in developing it. Changes in dietary patterns, poor reactions to medications and bouts of infections like gastro can also all change the way the body reacts to food chemicals and make someone suddenly more sensitive to them.

How do I know if I have food chemical sensitivity?

Food chemical sensitivity can present in multiple ways, usually triggering symptoms such as hives, headaches, sinus and/or breathing issues, mouth ulcers, nausea and digestive upset, although symptoms can vary. Unlike FODMAPs, which are poorly digested and trigger gastrointestinal symptoms as a result of excess water and production of gases in the bowels, food chemicals are properly absorbed by the body. Food chemicals are thought to irritate sensitive nerve endings, which explains why symptoms can occur outside of the digestive system.

Much like FODMAPs, food chemicals do not cause any damage to the body and therefore it can be hard to detect when you have a sensitivity to them. There is currently no reliable medical test that can diagnose a sensitivity, so it is important to contact your medical professional if you believe you may be experiencing the above symptoms in relation to food. They can refer you to a Dietitian, who can assist you with a structured elimination diet and challenge procedure.

If you have completed the initial phase of the low FODMAP diet and did not experience improvement in your IBS symptoms, there may be many reasons.  One option you might consider exploring is a low food chemical diet with a Dietitian. In either situation, a Dietitian can guide you through an elimination diet where you remove food chemicals from your diet for 3-4 weeks. If your symptoms improve following this trial, it is likely that you have a food chemical sensitivity and your Dietitian can help you to complete structured food challenges. These challenges will help you to determine which specific food chemicals you are sensitive to and how much you can tolerate (known as your threshold). Once these are determined, a Dietitian can help you to develop your own unique eating pattern that incorporates suitable foods that minimise symptoms whilst maximising dietary variety and nutritional value.

Can I have both IBS and a food chemical sensitivity?

As FODMAPs and food chemicals are different compounds, it is possible that you could have both IBS and a food chemical sensitivity. It can be difficult to distinguish between the symptoms of both, as they can cause very similar if not identical digestive symptoms, such as abdominal pain, bloating, wind, diarrhoea and constipation. The exception is the additional food chemical sensitivity symptoms, that range from skin rashes and headaches to mouth ulcers and breathing issues.

If you suspect that you have IBS or a food chemical sensitivity (or both!), it’s important to seek the guidance of a food intolerance trained Dietitian to help you through the process of determining your symptom triggers. Some foods that are considered low FODMAP are high in food chemicals (such as tomatoes and kiwi), so it can be hard to find foods that are suitable if you approach this challenge alone. In addition, both the low FODMAP diet and low food chemical diet can be quite restrictive, so the support of a Dietitian can ensure your diet is still nutritionally adequate and providing lots of dietary variety and gut-loving prebiotics throughout this process.

In summary

Food chemical sensitivities occur when people with sensitive nerve endings that line their body are exposed to food chemicals such as salicylates, amines and glutamate. Gastrointestinal symptoms can be similar to IBS symptoms, however non-life threatening or damaging symptoms can also occur elsewhere in the body. A strict elimination diet followed by structured food challenges is the best way to confirm a food chemical sensitivity and is best completed with the guidance of a food intolerance-trained Dietitian.

Written by: Amy Lilly (Accredited Practising Dietitian)
Reviewed by: Kiarra Martindale (Accredited Practising Dietitian)