Tartrazine appears to cause the most allergic and intolerance reactions of all the azo dyes, particularly among asthmatics and those with an aspirin intolerance. Symptoms from tartrazine sensitivity can occur by either ingestion or cutaneous exposure to a substance containing tartrazine.
A variety of immunologic responses have been attributed to tartrazine ingestion, including anxiety, migraines, clinical depression, blurred vision, itching, general weakness, heatwaves, feeling of suffocation, purple skin patches, and sleep disturbance.
Certain people who are exposed to the dye experience symptoms of tartrazine sensitivity even at extremely small doses, some for periods up to 72 hours after exposure. In children, asthma attacks and hives have been claimed, as well as supposed links to thyroid tumors, chromosomal damage, and hyperactivity.
The use of tartrazine was banned in Norway , and was also banned in Austria and Germany until the ban was overturned by a European Union directive. The United Kingdom's Food Standards Agency in April 2008 called for a voluntary phase-out of tartrazine, along with five other colorings, due to a reported link with hyperactivity in children.
Controlled Trial of Oligoantigenic Treatment in the Hyperkinetic Syndrome, Egger J, et al, The Lancet March 9, 1985 MedLine || Full Text
"76 selected overactive children were treated with an oligoantigenic diet. 62 improved, and a normal range of behaviour was achieved in 21 of these. Other symptoms such as headaches, abdominal pain, and fits, also often improved…. Artificial colorants (Yellow No. 5) and preservatives were the commonest provoking substances, but no child was sensitive to these alone."
Assessment of chemical factors in relation to child hyperactivity. Ward NI, Journal of Nutritional & Environmental Medicine (Abingdon); 7 (4). 1997. 333-342. MedLine || Full Text
"...Only hyperactive children showed a significant reduction in blood serum zinc levels and an increase in urinary zinc output following the consumption of E102 [tartrazine] and E110 [sunset yellow]. . . For the 23 children who consumed a tartrazine beverage there were increased levels of overactivity (n = 18 children), aggressive (n = 16) and/or violent (n = 4) activity, poor speech (n = 2), poor coordination (n = 12), and the development of asthma and/or eczema (n = 8). Most of these were severe or moderate changes. Only one control child showed minor behavioural responses to tartrazine."