Grapefruit

Grapefruit is often thought of as an effective slimming aid, because it contains enzymes that catalyse the breakdown of fat in the body. But did you know eating the fruit could prevent signs of ageing, too? It's true, thanks to high levels of vitamin C and a flavanoid called naringenin - the substance which gives the fruit its bitter taste. This binds to toxins and helps to flush them out of the body's system before they can cause any damage.