Feel-good diets

We also look at the Greek island of Crete, whose changing cuisine is tainting its healthy image. Once hailed for a diet that led to a long life, its residents are now considered among the most obese in Europe.

And finally, could a drop of collagen on our plate keep old age at bay? Having long been popular in Japan, the protein normally associated with cosmetic surgery is beginning to appear in Western dishes. Advocates say eating collagen plumps up the skin and gives us a youthful appearance.