The Influence of the Chemical Additive Tartrazine on the Zinc Status of Hyperactive Children — a Double-blind Placebo-controlled Study

Ward NI, Soulsbury KA Zettel VH, Colquhoun ID, Bunday S, Barnes B (1990) Journal of Nutritional Medicine 1(1)

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Abstract:

Twenty hyperactive male children were assessed for zinc status and compared with 20 age-matched controls, and a double-blind placebo-controlled study of the effect of the chemical additive tartrazine (E102) on the zinc status of 10 hyperactive males versus 10 age-matched controls is reported.

Analysis of tartrazine in commercial orange beverages was performed by high performance liquid chromatography using a reverse-phase ion-pair system. The influence of tartrazine upon zinc status of blood sera, washed scalp hair, urine, saliva and fingernails of hyperactive and control children is assessed. Zinc measurements were undertaken by inductively-coupled plasma-source mass spectrometry (ICP-MS).

The tartrazine content of various commercial orange beverages ranged from 0.58–4.16 μg ml−1.

Low zinc status is associated with the hyperactive compared with control for urine (p<0.001), scalp hair (p<0.001), serum (p<0.01), 24-hour urine (p<0.01) and fingernails (p<0.01). Saliva showed no statistically significant difference.

Tartrazine induces a reduction in serum and saliva zinc concentrations and an increase in urinary zinc content with a corresponding deterioration in behaviour/ emotional responses of the hyperactive children but not the controls.

FAB RESEARCH COMMENT:

This small study found significantly lower zinc status in ADHD children than controls, assessed using multiple measures (serum, urine and hair samples).

These findings are consistent with earlier reports of zinc deficiency in ADHD, which flagged the fact that zinc is an essential co-factor for in-vivo conversion of the short-chain omega-3 and omega-6 fatty acids found in plant and seed oils into the longer-chain forms that are biologically essential - and critical for normal brain and nervous system functioning. See:

Colquhoun & Bunday 1981 - A lack of essential fatty acids as a possible cause of hyperactivity in children

Of particular interest in this latest study was the finding that in the ADHD children - but not in controls - their zinc levels were further depleted following ingestion of the artificial food colouring tartazine ('sunset yellow') in a placebo-controlled trial.

Zinc is needed for the operation of at least 300 enzymes in the brain and body - and inflences the status and/or activity of many other key nutrients - so deficiencies could potentially cause or exacerbate a wide range of mental as well as physical symptoms associated with ADHD.

Findings from another recent study also indicate that low zinc status in ADHD children may reduce the effectiveness of stimulant medicatons: