Does gratitude or optimism help your health and longevity?

People who regularly reflect on things they are grateful for report more positive feelings and better overall well-being than people who do not. This also held true for people with a chronic neuromuscular condition. The effect on mood was the most consistent finding, although not all measured outcomes improved.

There is also something to be said for stress and depression in the workplace. Nine randomised studies in employees showed that gratitude interventions can noticeably reduce stress and low mood. One caveat: people who completed the exercise four times or fewer saw no effect. Greater regularity appears to help. Effects on broader measures of well-being were mixed, and the studies varied considerably in design, so firm conclusions cannot yet be drawn.

For sleep quality there are cautious indications: in five of the eight studies that measured sleep, subjective sleep quality improved. For physical outcomes such as blood pressure, blood sugar or inflammation, however, the evidence is thin. There was only one or two studies per outcome, with mixed results and methodological limitations.

On the basis of the available studies, nothing concrete can be said about optimism and longevity. Optimism appears in the sources only as a descriptive characteristic of well-being among healthcare professionals, not as an investigated intervention with measurable health outcomes. The question of whether optimism helps you live longer is not answered by the studies provided.

On a practical note: keeping a gratitude journal has a low barrier to entry, costs nothing, and appears to be least useful as a one-off exercise. People who do it consistently, several times a week, have the best chance of a measurable effect on mood and possibly on sleep. Do not expect hard guarantees for your physical health based on current research.