For years, it was something in the olive oil. Scientists, puzzled by the lengthy lifespans of Mediterranean communities, pointed to the condiment as a key ingredient in the elixir of life.
Then there was Japan, whose lengthy spell at the top of global longevity rankings was put down to its citizens' low-fat diet and love of raw fish.
Now, with South Koreans storming to the top of the table, the question is: is there something in the kimchi?
The east Asian nation this week stole global headlines and the crown for longest lifespans after a study from Imperial College London found that, by 2030, its citizens are set to live longer than anyone else. Girls born in South Korea 13 years from now can expect to live on average to the ripe age of 91. South Korean males — typically more partial to a drink and a smoke — will have to settle for 84, ahead of men anywhere else in the world.
These developments underscore the country's remarkable transformation over the past 70 years from an impoverished war-torn nation to a leader in technology, business — and now lifespan. As recently as the mid-1980s, life expectancy for South Korean women was less than 75, while men could not expect to make 65.
So what is the secret? On this, there is some consensus: investments in medical care, a health-conscious culture and a hearty diet underpinned by the ubiquitous presence of fermented vegetables, most notably kimchi.