Amaranth, the most common red food colour in both the US and UK, was banned last week in the US after a study suggested that it caused cancer in rats. […] The situation is confused, however, because the test rats were mixed up with the controls in the US tests, and because some tests have indicated hazards while similar tests show the dye to be safe. In April 1975, the joint FAO/WHO Expert Committee on Food Additives (JECFA) gave amaranth temporary approval through 1978.