For years, so-called blue zones have been cited as places where people live unusually long, healthy lives. More recently, those claims have come under scrutiny, with critics arguing that age records from these regions may be unreliable. A new peer-reviewed study challenges that skepticism, concluding that the demographic evidence behind the original blue zones is scientifically sound.
The paper, published in The Gerontologist, was authored by Steven N. Austad, PhD, scientific director of the American Federation for Aging Research, and Giovanni M. Pes, MD, a professor of medicine at the University of Sassari in Italy. The authors reviewed decades of demographic research used to identify blue zones and assessed whether reported ages in these populations were validated using accepted scientific standards.
“Extraordinary claims about longevity demand extraordinary evidence,” Austad said. “What we show in this paper is that the original blue zones meet — and often exceed — the strict validation criteria used worldwide to confirm exceptional human longevity.”
The researchers focused on four regions that formed the basis of the original blue zones concept: Sardinia in Italy, Okinawa in Japan, Ikaria in Greece, and the Nicoya Peninsula in Costa Rica. In each case, they found that age claims were confirmed through multiple independent sources, including civil birth and death records, church archives, genealogical reconstruction, military and electoral registries, and in-person interviews. Individuals whose ages could not be conclusively verified were excluded from analyses.
“These methods were developed precisely because age exaggeration has been common throughout history,” Pes said. “Blue zones are not based on self-report. They are based on painstaking cross-checking of records, often going back more than a century.”
Importantly, the authors emphasize that blue zones were never defined by a handful of extreme outliers, such as centenarians, but by population-level survival patterns showing a higher probability of living to age 90 and beyond. They also note that blue zones are not permanent. As societies modernize and lifestyles change, previously observed longevity advantages can weaken or disappear, as has been documented in parts of Okinawa and Nicoya.
The study does not argue that any single behavior explains long life. Instead, it reinforces the idea that blue zones offer valuable case studies for understanding how a combination of factors, including diet, physical activity, social structure and environment, may contribute to healthy aging. While genetics likely play a role, the authors point to lifestyle patterns as central drivers of longevity at the population level.
The findings are relevant for nutrition research because blue zones are often referenced in discussions about eating patterns associated with long-term health. By reaffirming the validity of the underlying demographic data, the authors argue that these regions remain legitimate subjects for studying how diet quality, food traditions and broader lifestyle factors intersect with aging.
At the same time, the paper serves as a reminder of the limits of blue zones research. The authors caution against oversimplifying their findings or treating any one region’s habits as a universal prescription. Blue zones, they argue, are best understood as natural experiments that can inform, but not dictate, public health recommendations.
Steven N. Austad’s research is supported by Protective Life Corporation and the U.S. National Institute on Aging. Giovanni M. Pes’ research is supported by the University of Sassari, Italy.