Researchers followed more than 71,000 people and found that the most optimistic were up to 70% more likely to live past 85 than the least optimistic — an association that remained even after accounting for exercise, diet, smoking, illness and depression.

Researchers followed more than 71,000 people and found that the most optimistic were up to 70% more likely to live past 85 than the least optimistic — an association that remained even after accounting for exercise, diet, smoking, illness and depression.

Seventy per cent is the kind of number that can turn a subtle epidemiological result into a slogan. In this case, the underlying finding was genuinely striking. Across two long-running American cohorts, people with the highest optimism scores lived longer on average and had better odds of reaching 85 than people with the lowest scores. The association persisted after researchers accounted for depression, existing illness and a long list of healt…