Food Additives and Preservatives

Additives and preservatives are the substances added to food. They can be broadly separated according to their functions, but a single additive may perform a variety of defined functions.

Preservatives:
To stop germs and moulds from spoiling food or making it unsafe; an example is sodium benzoate in fruit juices

Antioxidants:
To stop fats and oils from going rancid; for instance, ascorbic acid in butter

Emulsifiers and stabilisers:
To mix foods, particularly oils and water, and prevent them from separating; an example is calcium alginate in ice cream

Colours:
To make food more colourful; two examples are allura red , tartrazine and sunset yellow

Flavour enhancers:
To bring out flavours in food; a well known one is monosodium glutamate (MSG)

Anti-caking agents:
To stop powdery foods from forming lumps (as in salt)

Nitrates:
Acts as a preservative in many foods, but may be added to foods, such as pork, to give a pink colour.


Are Additives and Preservatives Necessary?

Yes they are in the majority of cases. As our cities grow larger and lifestyles more hectic, it becomes difficult for people to obtain fresh food. Without preservatives or additives, a great amount of food would "go off" before being bought. For example, bread would last only about two days before becoming stale.


Are Additives Safe?

The vast majority of additives and preservatives appear to be safe. They have been tested by many laboratories throughout the world before being used in foods. However, individuals may be "sensitive" to various additives and preservatives. Government agencies control which substances, and in which amounts, may be used in the production of food.



Who do they affect?

Individuals with some form of allergy, e.g. asthma, hayfever, urticaria, etc., will be affected by these substances. A few additives and preservatives can affect non-allergic people too. Some of these substances cause more reactions than others. For example, reactions to sulphur dioxide and sodium benzoate occur more commonly in asthmatics than reactions to the colorant tartrazine.



What reactions can occur?

Reactions are not "true" allergies as one sees with an egg allergy, but usually a type of chemical reaction. Reactions depend on the type of preservative or additive ingested. These may include vomiting, rashes, hives, a tight chest, headaches, worsening of eczema, and many other symptoms. Combinations of symptoms may give your doctor a strong clue as to the substance causing the reaction

Are there other substances that these reactions may be confused with?



Absolutely! Similar reactions may occur with an allergy to a food such as egg, nuts, etc. Some foods have natural chemicals that may affect you too. For example, fish that's not fresh may have a high level or histamine, cheese may have tyramine, and you may react to the histamine in wine and not the sulphur dioxide!

Histamine is an important protein involved in many allergic reactions. Allergies are caused by an immune response to a normally innocuous substance (e.g. chemicals,pollen, dust) that comes in contact with lymphocytes specific for that substance, or antigen. In many cases, the lymphocyte triggered to respond is a mast cell. For this response to occur, a free-floating IgE (an immunoglobulin associated with allergic response) molecule specific to the antigen must first be attached to cell surface receptors on mast cells. Antigen binding to the mast cell-attached IgE then triggers the mast cell to respond. This response often includes the release of histamine.



Which Additives result in Side Effects?



We cannot hope to cover all the additives and preservatives that may result in reactions, but these are some of the more important ones.


Preservatives:


Sulphur dioxide and sodium benzoate often cause "tight chests" in individuals who have asthma. Many people also complain of a scratchy feeling at the back of their throats. Although these are the common reactions, others such as rashes may also occur. Sulphur dioxide may be labelled as sodium metabisulphite, potassium metabisulphite, sodium or potassium bisulphite, or sulphite. CSPI found six scientific studies proving that sulfites could provoke sometimes severe allergic reactions.

Foods that may contain sulphur dioxide include. (shortened list):

* some fruit juices
* concentrated soft drinks
* dried fruit
* boerewors
* vinegar
* wine, beer
* some sauces
* pickles
* hamburger patties.


Foods that may contain sodium benzoate include: (shortened list):

* fruit juices
* soft drinks
* foods with fruit.



Antioxidants:

These are substances that prevent oily foods from becoming rancid. Some individuals complain of reactions to BHA or BHT. Fortunately, reactions to these substances are not common. Reactions include rashes, hives, and occasionally "tight" chests.

Colourants:

Colorants may be natural or synthetic. Reactions, although not common, can occur to both types. The best known colorant is tartrazine. Tartrazine is an azo dye, so if you react to this colorant, you should avoid all of the azo dyes. Tartrazine appears to cause the most allergic and/or intolerance reactions of all the azo dyes, particularly amongst those with an aspirin intolerance and asthmatics. Other reactions can include migraine, blurred vision, itching, rhinitis and purple skin patches, (because of this more use is now being made of Annatto (E160b). In conjunction with Benzoic acid (E210) tartrazine appears to create an over-activity in children.

Foods that may contain colorants include: (shortened list):


* fruit juices
* soft drinks
* sweets
* desserts
* toppings
* syrups
* cooking oils
* sauces
* pickles.



Emulsifiers and Stabilisers:

These are substances that keep oil and water mixed, as in mayonnaise. These substances do not cause reactions.Carrageenan is widely used as an additive by the food industry for its gelling, thickening and stabilising properties(e.g Hot Cocoa).A recent review of animal studies suggested that degraded carrageenan may be associated with cancer in the gastrointestinal tract.Used in salad dressings, prepared meat and fish, flavoured milk, processed cheese, ice cream, evaporated milk, cream, cottage cheese, sour cream, infant formula, alcoholic beverages, sauces and dressings.

Gum Acacia is used in food as a thickener, stabiliser, glazing agent and emulsifier, and is readily water-soluble.Typical products include chewing gum, sweets, jelly, fondants, beer, soft drinks, fruit squash, wine.May cause weak allergic reaction in some individuals. May act as an irritant.


Flavour Enhancers



The most famous of these is monosodium glutamate, commonly called MSG. Eating foods with this additive may result in tight chests in asthmatics. This reaction may occur immediately or 6 to 12 hours later on. A condition called "Chinese Restaurant Syndrome" may occur in any individual. This reaction can occur about 20 minutes after a food containing MSG is eaten on an empty stomach. Typical symptoms include headache, a burning sensation along the back of the neck, chest tightness or pain, nausea, sweating, and a sensation of facial pressure. "Pins and needles" or tingling may be experienced in the limbs or face and head. It is not a common condition.



Foods that may contain MSG include: (shortened list):


* Oriental food
* packet soups
* sauces
* soya sauce
* seasonings
* Aromat
* MSG is also thought to occur naturally in mushrooms and tomatoes.





Sweeteners:

The artificial sweetener aspartame, may cause rashes or hives in sensitive individuals. This sweetener is added to many "low calorie" foods. Saccharine , which is one of the oldest artificial sweeteners in the market, is around 300 times sweeter than ordinary sugar. Despite the fact that saccharine is 300 times sweeter than sugar, it tends to leave a bitter taste after eating.

Sucralose is the newest non nutritive sweetener on the market.A lot of the controversy surrounding sucralose stems from the fact that it was discovered while trying to create a new insecticide.The presence of chlorine is thought to be the most dangerous component of sucralose. Chlorine is considered a carcinogen .

Aspartame sugar substitutes cause worrying symptoms from memory loss to brain tumours. But despite US FDA approval as a ‘safe’ additive, aspartame is one of the most dangerous substances ever to be foisted upon an unsuspecting public. These reactions have included: headaches/migraines, dizziness, seizures, nausea, muscle spasm, weight gain, rashes, depression, fatigue, irritability, tachycardia, vision problems, breathing difficulties, anxiety attacks, vertigo, tinitus, memory loss and joint pain.



Salicylates:

Acetyl salicylic acid found in aspirin may result in a "tight" chest or hives in some asthmatics. A different form of salicylic acid can be found in a variety of spices and foods. Some health professionals believe that this form can result in many side effects, including hyperactivity in children. However, this is still controversial.

Foods that may contain salicylic acid include: (shortened list):


* ice cream
* curry powder
* paprika
* dried thyme
* berries
* ginger
* almonds
* apricot
* oranges
* tea,
* honey



How do I know whether I am affected?

This may not always be obvious. In some instances, the reaction will immediately follow the ingestion of an additive or preservative, as with sulphur dioxide and sodium benzoate. In other cases, the reaction may be delayed for 6 to 24 hours.

What can I do to see if I am affected?

You may have to keep a diary and record all the food you eat, the time it was eaten, and when the reaction occurred. You will then need to see if there is a pattern to the reaction. Unfortunately, there is no blood or skin test available to check whether you are affected. Your doctor may suggest a "challenge" with the substance to see if you are indeed affected.

What treatment must I take if I am affected?

Read labels on foods very carefully and avoid all food that contains the preservative or additive that you are affected by. The Food Intolerance Databank has lists of foods that are "free from" a variety of preservatives and additives. You may have to follow a preservative and additive free diet for at least two weeks to check whether you are indeed affected or not. Your local dietician will assist you in drawing up a suitable diet.