• franceswalker@thefoodinto

Combining low FODMAP & low Chemical elimination: part 1

Updated: Jun 4

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; hives, sinus or unresolved gut issues, then modifying your natural food chemical intake may be worth exploring.

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 although nutritional supplementation may be required. Compromises need to be made to ensure the diet is nutritionally adequate 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 have some overlap.

In fact some people who are sensitive to food chemicals will often get some relief initially after starting a low FODMAP diet due to these similarities, however some symptoms can persist despite some noticeable improvement.

High FODMAP foods that may be removed 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 food chemicals.

Low FODMAP and Foods Chemical foods

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

  • Eggs

  • Fresh meat 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 natural food chemicals.

  • Some 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 snacks 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 many sauces in small amounts as long as there is minimal added onion or garlic.

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

  • Added flavour components which are high in glutamates

  • 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. No good for the Low FODMAP elimination diet.

HIGH FOOD CHEMICALS: large amounts of garlic, capsicum, onion, lime, chilli, ginger and coriander. No good for the low chemical elimination diet.

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

Differences between Low FODMAP and low chemical elimination

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

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

  • Many vegetables low in salicylate are high in FODMAPs eg leek + Brussel sprouts

  • Chocolate is super high in the natural food chemical: amines so needs to be avoided (big trigger for migraines)

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

  • While legumes are generally fine on the low chemical elimination diet, only canned lentils (drained and rinsed) are low FODMAP for a normal serve

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 20/9/2019


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.