People are more successful in taking up healthy habits if their partner makes positive changes too, according to research published in JAMA Internal Medicine today (Monday).

Scientists at UCL funded by Cancer Research UK, the British Heart Foundation, and the National Institute on Aging looked at how likely people were to quit smoking, start being active, or lose weight in relation to what their partner did.

They found that people were more successful in swapping bad habits for good ones if their partner made a change as well.

For example, among women who smoked, 50 per cent managed to quit if their partner gave up smoking too at the same time, compared with 17 per cent of women whose partners were already non-smokers, and eight per cent of those whose partners were regular smokers.

The study found that men were equally affected by their partners and were more likely to quit smoking, get active, or lose weight if their partner made the same behaviour change.

The research looked at 3,722 couples, either married or living together and over the age of 50, who were taking part in the English Longitudinal Study of Ageing (ELSA).

Professor Jane Wardle, director of Cancer Research UK's Health Behaviour Research Centre at UCL (University College London) and one of the study authors, said: "Unhealthy lifestyles are a leading cause of death from chronic disease worldwide. The key lifestyle risks are smoking, excess weight, physical inactivity, poor diet, and alcohol consumption. Swapping bad habits for good ones can reduce the risk of disease, including cancer.

Dr Sarah Jackson, lead author of the study at UCL, said: "Now is the time to make New Year's resolutions to quit smoking, take exercise, or lose weight. And doing it with your partner increases your chances of success."

Dr Julie Sharp, Cancer Research UK's head of health information, said: "Making lifestyle changes can make a big difference to our health and cancer risk. And this study shows that when couples make those changes together they are more likely to succeed.

"Getting some support can help people take up good habits. For example if you want to lose weight and have a friend or colleague who's trying to do the same thing you could encourage each other by joining up for a run or a swim at lunchtime or after work. And local support such as stop smoking services are very effective at helping people to quit.

"Keeping healthy by not smoking, maintaining a healthy body weight and being active can all lower the risk of cancer, and the more people can help and encourage each other the better."