Don't tell Bluto. Younger readers may need to be told that this oafish sailor, with his huge torso and beefy arms, was the arch-enemy of the cartoon character Popeye the Sailor Man. For 30 years, before and after the Second World War, weekly battles between the duo dominated the world of animated films. Despite his smaller physique, Popeye always triumphed over his nemesis with the aid of a can of the super-food spinach. For decades, this was suspected by the children as an adult ploy to persuade them to eat a vegetable which rarely appeals to children's palates. But now we know there was a scientific truth behind the parental instruction. Swedish scientists have discovered that spinach, or rather the nitrous oxide it produces when it comes in contact with human saliva, can lower blood pressure.

The news comes on the heels of research at Manchester University which showed that spinach, or the lutein in it, is the best natural medicine in combating age-related macular degeneration, which is the leading cause of blindness in Western society and affects 29 per cent of women over the age of 75.

Bizarrely, however, scientists say the nitrate benefits of the wonder food are countered by the use of strong mouthwash – something else not to tell Bluto.