Flavours and Flavour Enhancers: natural or artificial, what's the difference?


· under new labelling regulations, it is not possible to distinguish between artificial and natural flavours

· this doesn’t matter because they’re all made of the same chemicals in giant chemical factories and chemically there is little difference

· the problem with adding flavours made in factories – whether natural or artificial - is the size of the dose because it is possible to get much higher doses than you would in nature

· flavour additives are not the same as flavour enhancers

· children and adults who are affected by additives such as artificial colours and natural chemicals such as salicylates are likely to be affected by high doses of artificial flavours. You can choose to avoid all strong flavours, or choose to avoid all added flavours except vanilla.



Consumers who read food labels are often surprised to see that there are added ‘flavours’ in most products. If, like many people, you think natural flavours are good and artificial flavours are bad, you need to know more about these additives.

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Why flavours are added to processed foods

Flavours are used in processed food because overprocessing destroys flavour. When you drink freshly made juice, it needs no added flavours. But by the time apple juice, for example, has been centrifuged, pasteurised, filtered, clarified and cold-stabilised, much of the original flavour has been lost.

The labelling rules have changed

Until recently, Australian food labels followed the European tradition of describing flavours as natural, artificial or nature identical. For example, a strawberry-flavoured yoghurt could contain • natural flavouring substances whether derived from strawberries or not • a nature identical flavouring substance than has been synthesised, but is chemically identical to a substance found in nature, or • an artificial flavour, that has been synthesised and has not yet been identified in any natural product. While you can still find these terms on some product labels in Australian supermarkets, the labelling regulations changed in 2002, so technically, the term ‘natural flavours’ does not now comply with the code.

Flavours are secret

Under the new regulations, flavours must be declared in the ingredient list as either ‘flavour’ or ‘flavouring’, or a specific name or description of the flavouring such as ‘vanilla’. There’s no mention of natural or artificial, and although the food manufacturers know whether they are using artificial flavouring substances, the consumer does not. Should you be concerned?

The fact is that most processed foods contain flavouring additives that have been made in giant chemical factories. There are more than two thousand approved flavouring chemicals that don’t have to be described on food labels because they are considered to be closely guarded trade secrets. When the word ‘flavours’ appears on an ingredient list, it means those flavours have been man-made in a laboratory even if this could be described as natural by the definition above. Natural flavours, nature identical flavours and artificial flavours could contain exactly the same chemicals although consumers can't tell what's in them because of the secrecy surrounding flavour formulas. As author Eric Schlosser says in his bestselling book Fast Food Nation: ‘Natural and artificial flavours are now manufactured at the same chemical plants, places that few people would associate with Mother Nature. Calling any of these flavours “natural” requires a flexible attitude toward the English language and a fair amount of irony.’

If you studied high school chemistry, you probably made artificial banana flavour as part of the curriculum. It’s done by combining amyl alcohol and acetic acid in the laboratory using sulphuric acid as a catalyst and not a banana in sight. You will probably remember the result, a chemical called amyl acetate that smells surprisingly like ripe bananas - because it’s the dominant flavour chemical in bananas. If a solvent is used to extract this chemical from bananas, the resulting amyl acetate is then regarded as a natural flavour, despite being the same chemical as the amyl acetate made without bananas. Other flavour chemicals include ethyl propionate for a fruity flavour, cinnamic aldehyde for cinnamon, diacetyl for butter (see box) and there are several thousand more.

Butter flavour and popcorn lung disease

The butter flavour diacetyl – used in products such as microwave popcorn - has been linked to a rare and deadly respiratory disease known as Popcorn Workers Lung. Its victims include young, healthy, non-smoking flavouring industry workers who have been exposed to vapours when diacetyl is heated. So far three workers have died, and many are awaiting lung transplants. It has been known since 1989 that diacetyl vapour is irritating to throat and lungs and laboratory studies in the 1990s showed that diacetyl vapours were highly toxic to laboratory rats, with effects likened to ‘inhaling acid’ by scientists. At this stage, no one knows whether consumers exposed to diacetyl fumes in their own homes are at risk. Dr David Michaels, who heads the George Washington University School of Public Health's Project on Scientific Knowledge and Public Policy, says that diacetyl was approved for food use based on studies that examined consumption, not inhalation. "There is compelling evidence that breathing diacetyl vapors causes lung disease and there is no evidence of a safe exposure level,” says Michaels, who has asked the Food and Drug Administration to remove diacetyl from the list of safe additives.


Flavours and smells are irretrievably linked because flavours are recognised mainly through the sense of smell. That is why you may notice that your food loses its flavour when you have a cold. You can test this for yourself by holding your nose while consuming a food with a strong aroma such as chocolate or coffee - you will have trouble identifying the characteristic chocolate or coffee flavour, although you can still distinguish the basic flavour, such as sweet, sour, salty or bitter. Up to ninety per cent of your perception of taste actually comes from your sense of smell, so the flavour of a food can easily be changed by keeping the same base flavour while altering the aroma, a technique often used in processed foods. There can be hundreds of volatile organic compounds (VOCs) - chemicals that are in a gaseous state at room temperature - involved in a complex aroma. The giant chemical companies that make flavour additives generally also make fragrances for perfumes, personal care and household cleaning products.

Why flavours can affect your health

The first step to understanding how flavour and fragrance additives can affect your health is to realise that all foods consist of natural chemicals. For example, an apple contains over 1000 natural flavouring chemicals, some of which are known to cause health problems for some people in big enough doses. Eating is a chemical balancing act. We have to balance the benefits of nutrients such as vitamins and minerals against the side effects of natural pesticides and other chemicals that may contribute to various conditions.

According to Schlosser, a typical artificial strawberry flavour – in foods such as yoghurts - will probably contain such chemicals as amyl acetate, amyl butyrate, amyl valerate, anethol, anisyl formate, benzyl acetate, benzyl isobutyrate, butyric acid, cinnamyl isobutyrate, cinnamyl valerate, cognac essential oil, diacetyl, dipropyl ketone, ethyl acetate, ethyl amyl ketone, ethyl butyrate, ethyl cinnamate, ethyl haptanoate, ethyl heptylate, ethyl lactate, ethyl methylphenylglycidate, ethyl nitrate, ethyl propionate, ethyl valerate, heliotropin, hydroxyphrenyl-2-butanone, alpha-ionone, isobutyl anthranilate, isobutyl butyrate, lemon essential oil, maltol, 4-methylacetophenone, methyl anthranilate, methyl benzoate, methyl cinnamate, methyl heptine carbonate, methyl naphthyl ketone, methyl salicylate, mint essential oil, neroli essential oil, nerolin, neryl isobutyrate, orris butter, phenethyl alcohol, rose, rum ether, gamma-undecalactone, vanillin and solvent. Chemically, there isn’t actually much difference between the list of chemicals in a real strawberry or in an artificial strawberry flavour.

It’s the size of the dose that matters

The problem for the consumer is not how the flavour additive is made, but the size of the dose consumed. Because man-made flavours such as artificial strawberry are so cheap, it is easy to add a lot more than you would ever eat in one serve of a natural food. While few people are affected by the food chemicals in one strawberry, when consumers - especially children - consume concentrated doses of some of the chemicals above, and particularly if they consume them many times every day in different foods, they can be affected in a variety of ways.

Effects induced by additives

  • headaches or migraines
  • rashes (hives, eczema, dermatitis, other itchy rashes)
  • stomach aches, bloating, reflux, constipation, bedwetting, sneaky poos
  • asthma, frequent cough, stuffy or runny nose
  • frequent colds, flu, ear infections
  • joint pains, swelling of the joints
  • heart palpitations, fast heart beat, pseudo heart attack


  • sleep disturbance (difficulty falling asleep, frequent night waking, night terrors, restless legs)
  • restlessness (loud voice, irritable, easily distracted, demanding, easily bored)
  • irritability (touchy or easily annoyed, loses temper, throws tantrums)
  • oppositional defiance (temper outbursts, often says no, refuses requests, defies rules, angry)
  • inattention (forgetful, disorganised, foggy brain, dreamy)
  • anxiety (lethargic, depressed, panic attacks)
  • unhappiness (grizzly, miserable, cries frequently)


Are you sensitive to salicylates?

Among the flavours in strawberries you can see a chemical called methyl salicylate. Salicylates - in most fruit, some vegetables, herbs, spices and other plant products - are the some of the chemicals most likely to affect sensitive consumers. When the use of man-made flavour additives became widespread in the 1960s due to the burgeoning popularity of processed food, Californian allergist Dr Benjamin Feingold discovered that ‘allergy’ symptoms caused by these additives were actually symptoms of salicylate sensitivity. Then chief of the Allergy Department at the Kaiser Foundation Hospitals, Dr Feingold was the first to report adverse health effects of these additives in a medical journal. In his article entitled ‘Recognition of food additives as a cause of symptoms of allergy’, he included the 1610 synthetic flavours and 502 natural flavours listed at that time.

In 1985, a comprehensive analysis of the salicylate contents of foods showed that there were salicylates in even more foods than Dr Feingold realised (see box). In general, the stronger the flavour of a food, the higher the salicylates. Flavourings such as vanilla are eaten in much smaller quantities than whole foods, so the amount of salicylates in vanilla flavour as eaten in a product such as icecream is very low, and much safer for some consumers than a strong fruit, mint, spicy or herbal flavour.

Salicylate Contents of Foods

Food mg salicylate per 100gm

Worcestershire Sauce 64.3

Mixed herbs, dry 55.6

Cinnamon powder 15.2

Peppermints, range up to 7.6

Tomato sauce, range up to 2.5

Orange 2.4

Vanilla essence 1.4

Strawberries 1.4

Pears, peeled 0.0

Source: A. Swain et al, J Am Diet Assoc, 1985, 85(8):950-960


Parents are most likely to see the effects of added flavours from children’s syrup medications, which can contain extremely high levels of flavouring. One mother described how her normally additive free two-year-old became ‘argumentative, rude, defiant, violent, uncontrollable, and began waking in the night for up to 3 hours’ while taking a course of antibiotic syrup for tonsillitis. Another recalled the effect of a colour free flavoured pain reliever on her toddler: ‘he became incredibly agitated, head banging, aggressive, thrashing ... inconsolable ... we rushed to the doctor (because we were to hop on an international flight the next day!) and he sent us off for urgent blood and urine tests. While waiting for the tests about 3 hours later my son suddenly regained his composure and became calm.’

Most people don’t realise they are affected because of the 30 minute rule

Confusion about the effects of food additives is largely due to the time delay before effects become obvious. Unlike peanut and other true food protein allergies which can occur within minutes, reactions to food chemicals can occur up to three days later. Salicylate research has shown that consumers are unlikely to identify the cause of their symptoms unless the reaction occurs within 30 minutes.

Additives at a glance


There are currently over 2000 flavour additives and 400 additives that must be described by name or number on labels. Of the non-flavour additives, about 60 have been linked to health and behavioural effects. People vary in their sensitivity and although colours are often associated with irritability, sulphites with asthma, and ribonucleotides with rash, any additive can be associated with any side effect.


  • over 2000 secret man-made flavour additives that don’t have to be identified by name or number

Flavour enhancers

  • glutamates (620-625; MSG is 621)
  • nucleotides (627 disodium guanylate, 631 disodium inosinate, 635 ribonucleotides)
  • HVP, HPP and other concentrated natural forms of glutamates


  • artificial colours and natural colour annatto (160b).


  • sorbates (200-203), benzoates (210-213), sulphites (220-228), propionates (280-282), nitrates and nitrites (249-252)

Synthetic antioxidants

  • antioxidants 310-312 (gallates), antioxidants 319-321 (TBHQ, BHA, BHT)


Flavour enhancers are not the same as flavours

Do not confuse added flavours with added flavour enhancers, another group of chemicals that occur naturally but can be concentrated or created by processing. Glutamates are often found in tasty foods but can be added in a concentrated form as MSG (monosodium glutamate), see box. As with salicylates or any other chemicals, the more you eat, the more likely you are to be affected. A few people are not affected at all, others are only affected when they eat extremely high doses, and others are so sensitive they will be affected even by small amounts. As a concentrate, MSG can easily be added to any foods in much greater quantities than in nature. A study of 59 normal volunteers found all except one reacted to MSG added to home-made chicken soup, with the most sensitive to the smallest amount (3 grams) and most subjects reacting to higher doses. Although the doses of glutamates in natural foods are tiny compared to added MSG, some sensitive consumers are affected by them.

Glutamate Contents of Foods


Food portion size mg glutamate per serve

Chinese soup 1 bowl 5000.00

Tomato juice 1 cup 0.83

Mushrooms 1/4 cup 0.09

Parmesan cheese 2 Tbsp 0.05

Sources: H. Schaumberg et al, Science, 1969, 163;826-82, U.S. Food and Drug Administration


If you’ve ever wondered how manufacturers can say ‘no artificial colours or flavours’ on products such as flavoured noodles which contain MSG (listed as flavour enhancer 621), the answer is that ‘flavours’ and ‘flavour enhancers’ are different classes of additives according to food regulators, flavours being ‘intense preparations’ added to impart taste and/or odour, whereas a flavour enhancer enhances the existing taste.

MSG (monosodium glutamate) was the first of the flavour enhancers. It was originally developed from a kombu seaweed extract by a Japanese scientist in the early 1900s and launched in the US in 1948, where it rapidly became a multi-billion dollar business used to intensify the flavour of tasty takeaways, snacks, soups, sauces and meat-based meals. There were early reports in medical journals of Chinese Restaurant Syndrome, a condition occurring within 30 minutes of MSG ingestion and characterised by headache, a burning feeling, facial pressure and chest pain, sometimes with diarrhoea, and occasionally with sweating and palpitations that could be mistaken for a heart attack. Later, there were reports of MSG-induced asthma. Due to extensive industry promotion of MSG as safe, targeted in particular at health professionals, adverse effects of MSG are now considered controversial in the medical literature although recognised by consumers and allergy clinics worldwide.

Consumers are frequently confused because manufacturers can hide sources of MSG in other ingredients. For instance, all the following ingredients may contain high levels of glutamates which don’t appear as MSG on the label: hydrolysed vegetable protein (HVP), vegetable protein extract (derived from wheat, soy beans or other vegetables), hydrolysed plant protein (HPP), yeast extract, vegetable extract, soy sauce, Worcestershire sauce and soy extract. There are many ways of describing these on a label. If a delicious ‘all natural’ spread, sauce, stock or seasoning seems to be made largely from soy bean, wheat or vegetable protein of any description, you would have to suspect that it has been broken down with acid in a laboratory to create free glutamates.

The new flavour enhancers

In the 1990s, a new set of flavour-enhancing chemicals called nucleotides were introduced. These additives (disodium guanylate 627, disodium inosinate 631, and ribonucleotides 635, a combination of the previous two) were developed to boost the flavour enhancing effects of MSG by up to 15 times and, like MSG, are made in giant factories where they are synthesised from yeasts and regarded as natural. They can appear in products labeled “No MSG” although usually there is some natural form of MSG such as yeast extract present. Since the introduction of nucleotide flavour enhancers, the Food intolerance Network has received more adverse consumer reports about these additives than any other, with some consumers complaining about ‘years of hell’. Some people who have tolerated moderate amounts of MSG all their lives can have dramatic reactions to ribonucleotides, with a variety of symptoms from itchy skin rashes (Ribo Rash), swelling of the lips, tongue or eyes, anxiety, heart palpitations, panic attacks, headaches, heartburn or muscle spasms to sleep disturbance or behavioural disturbance in children. Effects can become apparent any time from within minutes to 48 hours later several days later and can last for up for a week or more, sometimes coming and going during that time.

The 30 minute rule applies. Consumers who have a reaction soon after eating are more likely to work out what is affecting them. A woman who avoided MSG because of irritable bowel symptoms wrote: ‘I found some corn chips that advertised “No MSG” and bought them a few times before connecting them with a very uncomfortable feeling of restlessness, agitation and panic, heart palpitations, hot flushes and a "buzzing" sensation; I thought I was having a panic attack. Since recognising the link [with nucleotide flavour enhancers] I bought the chips once more to test the idea that this was the cause; after about 5 chips I started to feel the ‘buzzing’ and threw the rest of the packet away.’

Because of the delayed onset, some consumers have suffered from distressing symptoms for up to ten years before discovering the cause of their problems. For example, a dose of 635 in soup for Friday lunch can result in symptoms at midnight on Saturday, leaving consumers looking for something to blame in Saturday’s dinner. As well as extensive use in takeaways, packet snacks and ready meals, flavour enhancers are less obvious in vegetarian options such as vegie burgers, uncooked foods such as fresh stuffed or seasoned chicken, sausages and marinated meats or manufactured crabsticks in sushi, and these additives have tripped up even vegetarian healthy food consumers in apparently healthy foods such as vegetable stocks and stock cubes. More detail at Ribo rash factsheet.

Who should avoid flavour additives?

When processed food became a growth industry in the 1960s artificial flavours were widely used, but in the last twenty years - due to the consumer perception that natural flavours are healthier - there has been a move towards man-made natural flavours. As with many other industrial chemicals, most flavour additives have never been properly tested for their effects on humans and fall into the category of GRAS (‘generally recognised as safe’). A document from the food industry leaked to the Today Tonight TV show in Australia in May 2004 also revealed that some food manufacturers hide unlisted additives such as colours and preservatives in flavours added to foods such as children's custards.

As we have seen, there is no significant difference between many artificial flavours and their natural counterparts: it is the size of the dose that can cause problems. Some consumers are more sensitive than others. Some will not be affected at all; some will be affected only by large doses of food chemicals such as salicylates in strawberry flavoured sweets or medication, and those who are more sensitive will be affected when, for example, strawberries are concentrated in products such as strawberry yoghurt.

It is possible to avoid added flavours and flavour enhancers by avoiding highly processed foods. To stick with the doses provided in nature, you can add fresh strawberries to plain yoghurt or choose products with low or no flavours. Organic products will be some of the safest. For example, yoghurts are more likely to contain only real fruit as flavouring or will often specify ‘vanilla’ as the only flavouring additive. Organic chocolate tastes quite different from highly flavoured supermarket lines. If ‘flavour’ is listed, you are likely to find it refers to vanilla or essential orange oil. There are some people for whom even that will be too much. Children and adults who are sensitive to the smallest amounts of food chemicals - including those in unprocessed natural foods - will feel better if they avoid the higher salicylate fruit like oranges and stick to lower salicylate fruit such as pears.

If you have ever seen an obvious reaction to any additives or foods, even once, it is worth learning more about food intolerance. Whatever you see is usually just the tip of the iceberg. The effects of natural food chemicals can creep up slowly and leave you wondering why your child isn’t doing as well as you expected, or why you rarely feel as healthy as you should. Although children are the most vulnerable, adults can be affected too.

More information

Introduction to food intolerance

More about food intolerance:   Allergy or intolerance?     Additives to avoid    Salicylates

There's a brilliant chapter about flavour and fragrance factories in Fast Food Nation: what the all-American meal is doing to the world by Eric Schlosser, Penguin, 2002.

The regulations concerning flavours and flavour enhancers:

Letters to and from FSANZ regarding use of flavours as vehicles for un-declared colours and preservatives (May 2004)

The effects of natural food chemicals in The Failsafe Cookbook by Sue Dengate, Random House, new edition 2007

First to alert parents to the dangers of flavours: Feingold B, Hyperkinesis and learning disabilities linked to artificial food flavors and colors, Am J Nurs. 1975 ;75(5):797-803

Article on flavours from Clean Food Organic by Sue Dengate: Conventional processed foods leave a bad taste (360Kb PDF) 2007

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 November 2015