top of page
  • Writer's picturefranceswalker@thefoodinto

Combining low FODMAP & low Chemical elimination: part 1

Updated: Apr 8

Low FODMAP diets are often the first diet to trial for the management of IBS (irritable bowel) but some people may not get the relief they hoped for from the diet and feel that other food intolerances may be lurking.

If you have extra symptoms such as migraines, headaches, unexplained fatigue, chronic mouth ulcers, eczema or rashes that seem to be linked with food or unresolved gut issues, then you need to look beyond FODMAPs.

Potentially, salicylates, amines and glutamate sensitivity could be in play.

JOIN THE COMMUNITY: BRAND NEW Dietitian led Facebook group: Amines, Salicylates and Glutamates: The Food Intolerance Dietitian for great information and community support.

What do you do when you need to combine the low chemical as well as FODMAPs?

It can be done with careful guidance to ensure your diet is nutritionally adequate. Compromises often need to be made to ensure ta nutritionally balanced diet as a strict low FODMAP diet and a strict elimination diet do not mix.

When combining the two diets, what is initially obvious is that both diets have some common ground. Let's explore this first.....

High FODMAP foods that are also high in Food Chemicals

The RPAH (Royal Prince Alfred Hospital) food chemical elimination or FAILSAFE and the FODMAP elimination do have some overlap.

Some people who are sensitive to food chemicals will often get some relief initially after starting a low FODMAP diet.

As the Low FODMAP diet starts expanding over time as your confidence grows, some other foods may find their way back into your daily eating plan and thus cause a deterioration in your symptoms.

High FODMAP foods excluded from the diet that are also high in food chemicals include:

  • Honey

  • Onion

  • Mushrooms

  • Peas

  • Cauliflower

  • Avocado

  • Stone fruit: plums | peaches | apricots

  • Fruit juices

  • Dried fruit

The following table shows how these foods contain high levels of FODMAPs as well as naturally occurring food chemicals.

By going on a low FODMAP diet, you may also reduce the salicylate, amine and glutamate load as well which could be beneficial if you are intolerant to these naturally occurring food chemicals.

Low FODMAP and Low Food Chemical Chemical foods

There are a few staple foods that are suitable for both elimination diets

  • Eggs

  • Fresh meat (example chicken, lamb, beef) and fresh seafood

  • Some oils/ fats such as canola oil

  • Pure maple syrup or rice malt syrup

  • Wheat (needs to be limited for low FODMAPs eg 1 slice unpreserved white or wholemeal bread)

  • Oats

  • Many GF grains (but not all): rice, buckwheat, sorghum, millet and quinoa. Some GF grains such as corn or maize are too high in salicylates and glutamates.

  • Some plain GF BF cereals eg GF Weet-Bix, GF Special K, rice puffs

  • Lactose free cow's milk

  • Some alternative milks such as rice milk

  • Some treat foods such as So Good vanilla ice cream

Both low chemical and Low FODMAP limit commercial sauces

Sauces can be an issue for both diets, although the Low FODMAP diet can include a limited number of sauces if they are onion and garlic free sauces.

Commercial sauces are completely avoided in the chemical elimination diet mainly because of:

  • Added flavour

  • Additives such as artificial preservatives and flavour enhancers

  • Added herbs and spices which are high in salicylates

Take this stir-fry sauce above.

Ingredients: water, sugar, garlic, capsicum, onion, lime-4%, chilli 4%, thickener (modified corn starch), ginger, salt, food acid (acetic), coriander.

HIGH FODMAPs: Garlic and onion are in the top 1/3 of the ingredient list and since the ingredient list starts with the highest ingredient, it is safe to assume that this stir fry sauce contains a significant amount of garlic as well as onions.

HIGH FOOD CHEMICALS: Includes capsicum, onion, lime, chilli, ginger and coriander.

Taking out most commercial sauces will reduce both the FODMAPs as well as food chemicals.

low Chemical and low FODMAP diet: differences

There are quite a few differences between these 2 elimination diets:

  • Pears are the only fruit low in salicylates but are very high FODMAP

  • Many vegetables low in salicylate are high in FODMAPs eg leeks & Brussel sprouts

  • Dairy free of dark chocolate is low in FODMAPS but very high in amines ( a natural food chemical) so needs to be avoided (can be a big trigger for headaches and migraines)

  • Nuts are an issue for the chemical elimination diet- the only nuts that are ok are cashews which are high in FODMAPs

  • While legumes are generally fine on the low chemical elimination diet, only a limited amount of some legumes for example 1/4 cup canned lentils (drained and rinsed) are low FODMAP.

Despite these differences, a Low FODMAP and low chemical elimination diet can be trialled, but best done with guidance as certain compromises need to be made to promote good nutrition.

See part 2 for more information on combining the low FODMAP and chemical elimination diets!

Updated 08/04/2024


1. RPAH elimination diet handbook: with food and shopping guide. Anne Swain, Velencia Soutter, Robert Loblay, 2011 (revised edition).2. Monash University low FODMAP app. Version 2.0.9. Accessed 28/4/2018.


bottom of page