Sensible habits, mostly observational evidence — each one graded on its own studies.
The Blue Zones work distils long-lived places into a short list of habits — the “Power 9”. Most are good, ordinary advice. The question this page answers is narrower: how strong is the evidence for each one? Most of it comes from observational studies — people who do the habit compared with people who don’t — which shows a link but can’t prove the habit causes it. Our grades say so.
Evidence checked 2026-10-21. Grades are calculated from the studies listed, by fixed rules.
More daily steps went with lower death rates, up to a level that varied by age. Observational: active people differ from inactive people in many ways.
Stronger purpose in life was associated with lower mortality in adults over 50. An association, not proof that purpose causes it.
The PREDIMED trial found fewer major cardiovascular events with a Mediterranean diet plus olive oil or nuts, compared with a low-fat diet. Participants knew their diet (not blinded), and the trial was re-analysed after randomization problems. Beans: one observational study.
Two years of calorie restriction in healthy adults improved several heart and metabolic risk markers — results the trial reported as exploratory, not its main outcome. Nobody has shown it adds years in people.
Pooling 107 studies and correcting for the biases that made older studies look positive, low or moderate drinking was not linked to lower mortality; risk rose at higher amounts.
Women attending services more than once a week had lower mortality than those who never attended. Observational; social support explained part of it.
Across 148 studies, people with stronger social relationships were more likely to survive over the follow-up. Observational.
In the Framingham network, a person’s chance of becoming obese rose when a friend did. “Improved” here means the link was found — the effect described is the spread of a habit, good or bad.
These have research behind them that we have not entered yet. Until we have, we don’t grade them — “not yet graded” is not the same as “no evidence”.
Want to test one of these habits on yourself? Try a habit as an experiment.
“Blue Zones” and “Power 9” are trademarks of Blue Zones, LLC. This site is not affiliated with or endorsed by Blue Zones, LLC; we name the research only to grade it.