Looking on the bright side of life cuts the risk of suffering a heart attack or stroke, a scientific review has found.

Being optimistic has a direct impact on cardiovascular health - reducing stress hormones, pulse rate and blood pressure, experts found.

And people with a positive outlook eat better, do more exercise and are less likely to smoke and drink, their study showed.

Scientists at Northwestern University in Chicago and Harvard School of Public Health in Boston examined all existing evidence linking psychological well-being to cardiovascular health.

The researchers, whose work is published in the Journal of the American College of Cardiology, found mental outlook is ‘consistently related’ to heart disease.

Mental outlook is 'consistently related' to heart disease, a new scientific review found

They cited one study in which the 25 per cent of people with the highest optimism had a 38 per cent reduced risk of dying of heart disease.

Other papers have linked the feeling of having a ‘higher purpose’ in life with lower odds of having a stroke.

The researchers said doctors should consider using counselling or relaxation strategies such as yoga or tai chi to improve their patients’ mental health.

Lead author Professor Darwin Labarthe, of Northwestern University Feinberg School of Medicine, said: ‘We addressed how social environment, psychological well-being and the effectiveness of intervention strategies can help strengthen a patient’s outlook.

‘We focused on whether psychological well-being can be consistently related with a reduced risk of heart disease.’

He added: ‘Optimists persevere by using problem-solving and planning strategies to manage stressors.

‘If others are faced with factors out of their control, they begin to shift their goals and use potentially maladaptive coping strategies, which would ultimately result in raising inflammation levels and less favorable overall heart health.’

The research team found optimistic people less likely to smoke - and if they already smoke they are better at quitting.

High levels of psychological well-being are also associated with regular physical activity.

Optimistic patients sustained healthier diets by consuming more fruits and vegetables, and less processed meats and sweets, leading patients to maintain a healthier weight.

Other studies have found similar results for cancer, stroke, respiratory disease and infection.

Scientists suspect this may be because someone’s general mood alters the levels of harmful and beneficial hormones in their body.

Being optimistic, for example, reduces stress and anxiety hormones such as adrenaline and cortisol, which can place a burden on the heart and raise blood pressure.

Studies have also found people who are less stressed have lower cholesterol levels, are less prone to inflammation, have a better immune response and higher levels of antioxidants in the blood.

Having a strong support network also gives patients confidence and makes them more likely to act on medical advice, the scientists said.

Professor Labarthe said: ‘It may seem challenging to help patients modify psychological well-being in the face of a new medical diagnosis, but these events can represent a “teachable moment”.

‘Just having patient-centred discussions surrounding sources of psychological well-being and information about specific activities to promote well-being are a small, but meaningful, part of a patient’s care.’