1978 Birds Dream Topping advert from the UK

The ingredients for this “dessert topping mix with sweetener” from Kraft Foods read like a chemistry textbook, but Kraft craftily makes use of a somewhat ersatz formulation: “Contains a source of phenylalanine for vegetarians,” the label says. Look up phenylalanine – is it a warning or a recommendation? – and it turns out to be both. Phenylalanine is a constituent of the controversial artificial sweetener, aspartame. But it’s a good one; an essential amino acid that can’t be made by the body and needs to be supplied in the diet. So good old Dream Topping is good for you. Sort of.