Should ADI's Really be Taken in Isolation?

[Cronan McNamara (Creme)]

Recently the Food Standards Agency advised parents with children showing signs of hyperactivity that they should consider cutting certain artificial colours from their diets.

This was as a result of research, carried out by Southampton University, which suggested that eating or drinking certain mixes of artificial food colours together with the preservative sodium benzoate could be linked to a negative effect on children's behaviour including the potential to cause Attention Deficit Hyperactivity Disorder.

Attention Deficit Hyperactivity Disorder (ADHD or Hyperkinetic Disorder) is an extreme form of hyperactivity that is clinically diagnosed when specific patterns of behaviour occur together to a strong degree. It is characterised by inattention, impulsivity and hyperactivity such that they impair learning and function at home and at school.

Currently additives are regulated using the Acceptable Daily Intake (ADI) legal limit of exposure. The ADI is the amount of a food additive that could be taken daily for an entire life-span without appreciable risk. ADIs are typically expressed in mg per kg bodyweight (mg / kg bw). These limits are produced from animal toxicological studies. Chemical uses are limited so that consumer exposure levels higher than these ADI's are unlikely to occur.

The artificial food colours examined in the Southampton study are listed here with their associated ADIs:

* Sunset yellow (E110) [ADI: 2.5 mg/kg bw]
* Quinoline yellow (E104) [ADI: 10 mg/kg bw]
* Carmoisine (E122) [ADI: 4 mg/kg bw]
* Allura red (E129) [ADI: 7 mg/kg bw]
* Tartrazine (E102) [ADI: 7.5 mg/kg bw]
* Ponceau 4R (E124) [ADI: 4 mg/kg bw]

Conservative exposure assessments are performed for each chemical in order to ensure that the concentration levels in products with not cause consumer exposure levels greater than the ADI.

But, assessing each chemical individually for exposure and comparing them to the ADI does not address the risk of adverse effects from cumulative exposure to multiple chemicals.

In order to move from risk assessments for individual chemicals to multiple chemicals - a more realistic method of risk assessment is required.

The traditional deterministic tiered approach to exposure assessment is not effective any longer since it can only assess single chemicals individually and cannot tell the risk assessor anything about the probability of the adverse effect level being exceeded nor can it tell anything about the probability of high levels of cumulative exposure to a harmful cocktail of chemicals.

To perform an aggregate exposure assessment to multiple chemicals, it is important to use as much detailed information on food consumption, chemical occurrence, chemical concentration and even market share and brand information in order to make an estimate of aggregate exposures.

In a lot of cases, exact information for all of the above inputs is not available, so uncertainties exist in the model input. This should be handled using a probabilistic approach where the uncertainty in the input is quantified in the input.

Running the assessment with all of this information can give you a far more detailed picture of the risk of exposure to multiple chemicals.

CREMe Food Safety specialises in these detailed risk assessments and allows you to easily and accurately get results with your own data. If you would like more information on how we enable organisations to deal with the above issues, please contact us.

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References:

* Reference for ADIs: the Nordic Food Additive Database