Introduction to food intolerance

Effects of food additives
Additives that commonly cause problems
Natural food chemicals - salicylates, amines, glutamates, dairy and wheat/gluten
People rarely react to only one food chemical
What you can do
For more information


This factsheet is about food intolerance, not food allergy. To see more about the differences see Allergy or Intolerance?

Our food has changed drastically over the last 30 years, and so have food-related problems.

Additives are now used in healthy foods such as bread, butter, yoghurt, juice or muesli bars as well as in junk food. Reactions to food additives are related to dose, so the more you eat, the more likely you are to be affected. A British survey in 2007 found that:

  • most consumers underestimate how many additives they eat
  • the average consumer eats 20 additives per day (19 if foods are home-cooked)
  • most consumers don't know which foods contain additives.

Click on the video below to see a brief introduction.

(3.2Mb, 1:28)

         Effects of food additives can include

  • irritability, restlessness, difficulty falling asleep
  • mood swings, anxiety, depression, panic attacks
  • inattention, difficulty concentrating or debilitating fatigue
  • speech delay, learning difficulties
  • eczema, urticaria and other itchy skin rashes; angioedema or swelling of the lips etc often associated with rashes
  • reflux, colic, stomach aches, bloating, and other irritable bowel symptoms including constipation and/or diarrhoea, sneaky poos, sticky poos, bedwetting
  • headaches or migraines
  • frequent colds, flu, bronchitis, tonsillitis, sinusitis; stuffy or runny nose, constant throat clearing, cough or asthma
  • joint pain, arthritis, heart palpitations, racing heartbeat
  • and see more at the bottom of our home page.



         Additives that commonly cause problems

Artificial colours (in sweets, drinks, takeaways, cereals and many processed foods) 102 tartrazine, 104 quinoline yellow, 110 sunset yellow, 122 azorubine, 123 amaranth, 124 ponceau red, 127 erythrosine, 129 allura red, 132 indigotine,133 brilliant blue, 142 green S, 143 fast green FCF, 151 brilliant black, 155 chocolate brown

Natural colour 160b annatto (in yoghurts, icecreams, popcorn etc, 160a is a safe alternative)


200-203 sorbates (in margarine, dips, cakes, fruit products)

210-213 benzoates (in juices, soft drinks, cordials, syrups, medications)

220-228 sulphites (in dried fruit, fruit drinks, sausages, and many others)

280-283 propionates including cultured anything e.g. "cultured dextrose" (in bread, crumpets,
              bakery products)

249-252 nitrates, nitrites (in processed meats like ham)

Synthetic antioxidants (in margarines, vegetable oils, fried foods, snacks, biscuits etc)

310-312 Gallates

319-320 TBHQ, BHA, BHT (306-309 are safe alternatives)

Flavour enhancers (in tasty foods)

621 MSG, hydrolysed vegetable protein, yeast extract, 129 other names

627, 631, 635 disodium inosinate, disodium guanylate, ribonucleotides

Strong flavours in many foods and children's medicines (vanilla is safest)


         Natural food chemicals

  • Salicylates are increasing in our food supply, due to strong flavour additives, concentrated high salicylate foods such as tomato and onion powder in processed foods, and increased availability of out-of-season fruit and vegetables. Foods high in salicylates include strawberries, kiwifruit, avocadoes, sultanas and other dried fruits, citrus, pineapple, broccoli, tomato based pizza toppings, tomato sauce, olive oil, fruit juice and tea. Salicylate sensitivity can be triggered or worsened by medications such as aspirin and other NSAIDs (non steroidal anti-inflammatory drugs) such as Nurofen; drugs that interact with aspirin; lotions such as anti-arthritis creams; salicylate-containing teething gel and natural salicylates in herbal medications.

Nutritionists recommend 2+5 (2 serves of fresh fruit and 5 serves of vegetables per day), but most mothers who contact me do it the other way around – unlimited fruit, fruit juice, dried fruit and fruit flavoured products (e.g. muesli bars, fruit yoghurt), and don't worry too much about vegies because "fruit's so healthy". This can lead to a very high salicylate diet. One mother wrote:

"I got your book and did what it said. We have seen a huge difference, you have changed our lives forever and we are very grateful. My son used to live on fruit, especially sultanas. We were one of those 2+5 reversal families".

You can cut down on salicylates by drinking water instead of fruit juice or cordial; avoiding some of the highest foods - citrus, tomatoes, broccoli and grapes, and reducing fruit intake to 2 pieces of fresh fruit per day (best fruits are pears, rhubarb and 'just ripe' bananas). For more ideas, see one of my books. Or for best results with a severe problem, do the full RPAH elimination diet.

Fragrances such as fruit or eucalyptus are another source of salicylates. Since the 1970s, increasingly large doses have been added to products. In the UK, studies of new mothers found more headaches and depression in mothers and more asthma, diarrhoea, vomiting and ear infections in babies with increasing use of air fresheners and/or aerosols.

  • Amines occur naturally especially in protein foods such as cheese, chocolate, canned fish and processed meats.
  • Glutamates (like MSG) occur naturally especially in tasty cheeses, soy sauce, yeast extract, hydrolysed vegetable protein, soups, sauces, gravies, seasonings and many other foods. These are used in many 'No MSG' health food aisle rice-based snacks for children
  • A smaller number of people are sensitive to dairy foods and/or wheat or gluten.

People rarely realise that they are affected by salicylates, amines or glutamates unless they eat a very large dose in a short time (e.g. at Christmas or Easter) or until they reduce their intake. This is because these food chemicals are eaten so frequently that the effects fluctuate and can build up very slowly. One mother wrote:

'I cut back my five year old daughter's intake of fruit to about a quarter of what she normally had. Within days we saw dramatic changes. Her behaviour evened out ... she was more sensible and obliging, less aggressive and defiant - and altogether much more pleasant to live with.'

An experienced and supportive dietitian can supervise a three week trial of the RPAH (Royal Prince Alfred Hospital) elimination diet which is free of additives and low in salicylates and amines to find out exactly which food chemicals are contributing to problems. In our experience, this is the most effective elimination diet in the world. See our list of suitable dietitians

         People rarely react to only one food chemical

Most react to between 3-6 food chemicals. Overall, additives and salicylates are the main culprits, but everyone is different. See table below for the approximate percentage of overactive children likely to react to each challenge (other symptoms are similar)

75% - salicylates
65% - preservatives
55% - colours
40% - MSG and other flavour enhancers, natural glutamates
40% - synthetic antioxidants such as BHA 320
40% - amines
20% - dairy foods
<1% - gluten (figures are higher for other symptoms, up to 20% for irritable bowel). However, many people with food intolerance are affected by wholegrains and do better on white bread than wholemeal, puffed rice or rolled oats than e.g. weetbix.

Source: Loblay RH, Swain AR. Food Intolerance. In: Recent Advances in Clinical Nutrition' Vol 2, 1986. Libbey, London. Eds: Wahlqvist ML and Truswell AS, pp169-177.

         What you can do

  • Read Fed Up by Sue Dengate, available in bookstores, libraries and through our website - there's currently special offer for a set of both books and the DVD. Fed Up is the best book to start with.

Reader comment: - "The further I got into Fed Up, the more questions were answered - and I've definitely learnt heaps! I have decided to persevere with the diet. Oh my goodness, the vast majority of whining seems to have disappeared ... from story [1093]

Reader comment: - "My sister borrowed your DVD because her partner has IBS. He had no interest in watching it, so I gave her Sue's advice to put it on when he was around without asking him explicitly to watch it. She did, and within five minutes he was sitting next to her, glued to the screen. Although they haven't yet gone failsafe, he is now reading all labels and making better choices. My sister is lost for words!" - from story [923]

  • The Failsafe Cookbook from bookstores, libraries and through our website. This book contains information about food intolerance with heaps of easy recipes and hints. FREE Failsafe Booklets give a brief introduction.

Reader comment: - "I'm SO grateful for the simple, family friendly recipes in your book" - by email

  • An experienced and supportive dietitian can supervise a three week trial of the RPAH (Royal Prince Alfred Hospital) elimination diet which is free of additives and low in salicylates and amines to find out exactly which food chemicals are contributing to problems. In our experience, this is the most effective elimination diet in the world. See our list of suitable dietitians - if you have a problem finding someone email This email address is being protected from spambots. You need JavaScript enabled to view it. and say where you live, we may be able to recommend someone special, and there are some extremely experienced dietitians who do phone, email or skype consultations including overseas. Most people only need two or three consultations with a dietitian plus some phone or email backup. Dietitians say it cuts an hour off consultation time needed if people have read Fed Up before they go.
  • The RPAH Elimination Diet Handbook with food and shopping guide is a very useful reference if you are following the diet in the long term. However, in our experience, families are more likely to succeed if they read Fed Up first, see reader report below. Available from libraries, your dietitian or RPAH

    Reader report: - "I just got the RPAH book, after weeks with the two books of Sue's.... NO WONDER you were confused Trudie.. even after successfully failsafeing the last 3 months, this book does not actually LIST stuff like Sue's! go Sue Dengate for making it so so much simpler for us! thank you! I'm so glad I had her books first! Trudie see if your local library has a copy of either of the ones you don't have.. that is where i got my hard copy... plus if you go to, and do a 'preview' then 'decline' to buy.. they then offer it cheaper... my e reader (you can download free) copy was going to cost 29.95, then they offered it to me for 12.95! of course i bought it.. heard they do this a lot!" - from our facebook group

  • Join our very supportive Facebook Sue Dengate Failsafe Group


         For more information

How to start failsafe eating - a step-by-step guide

Salicylate factsheet

Amine factsheet

MSG and Natural Glutamates factsheet

Allergy or intolerance?

All factsheets alphabetically

FREE Failsafe Booklets

Checklist of Common Mistakes

The information given is not intended as medical advice. Always consult with your doctor for underlying illness. Before beginning dietary investigation, consult a dietician with an interest in food intolerance. You can see our list of experienced and supportive dietitians 

© Sue Dengate update October 2021