08/19/2026
On the Japanese island of Okinawa, a cluster of villages produced so many people who lived past 100 that researchers spent decades studying their diet and eventually traced part of the effect to a purple sweet potato that supplied roughly 60 percent of daily calories through the first half of the twentieth century
For most of the twentieth century, the purple sweet potato supplied roughly 60 percent of daily calories in Okinawan villages that produced the world's densest cluster of centenarians. What the data can and cannot tell us about why.
