Being happy and naturally optimistic cuts the risk of developing heart problems, say researchers.
They found that those who are enthusiastic, contented and believe the glass is half full rather than half empty have a better chance of keeping their heart healthy. It is the first study to find such a strong link between positive emotions and a lower risk of heart disease.
Findings published in the European Heart Journal reveal the potentially damaging effects of pessimistic thoughts and long-term negativity.
Lead researcher Dr Karina Davidson said it might be possible to help prevent heart disease by boosting positive emotions and called for more clinical trials in the area. She said: 'If the trials support our findings, then these results will be incredibly important in describing specifically what clinicians and patients could do to improve health.'
The U.S. study focused on 1,739 healthy adults over ten years. Nurses assessed participants' risk of heart disease and measured symptoms of depression, hostility, anxiety and the degree of expression of positive feelings, or 'positive affect'.
Positive affect is the experience of pleasurable emotions such as joy, happiness, excitement, enthusiasm and contentment.