People with asthma who are not obese could reduce their symptoms and improve their overall quality of life by exercising and maintaining a healthy diet, the results of a new study suggest.

Around 470,000 people in Ireland have asthma - that is almost 10% of the entire population. There are around 20,000 asthma-related Emergency Department (ED) attendances each year here, while over 5,000 people need to be admitted to hospital annually because of their condition.

The majority of people with asthma rely on daily medication to control their symptoms, and many of those affected are fearful of exercise, worrying that it could bring on or worsen their symptoms. Danish researchers decided to look into this further.

"There is increasing evidence that asthma patients who are obese can benefit from a better diet and increased exercise. We wanted to see if non-obese patients with asthma could also benefit," commented Dr Louise Lindhardt Toennesen of Bispebjerg University Hospital in Copenhagen.

The researchers split up 149 people with asthma into four groups. The first group was asked to follow a high-protein, low glycaemic index (GI) diet, and to include six portions of fruit and vegetables every day.

The second group participated in exercise classes three times a week in hospital. These classes included gentle activity and high intensity activity.

The third group followed the first group's diet and also took part in the exercise classes, while the final group did not follow the diet or take part in the classes.

The researchers found that despite people's concerns, high intensity training was safe and those who exercised saw an improvement in their fitness levels.

However, they also found that those in the diet and exercise group saw an improvement in the control of their asthma symptoms, and an improvement in their overall quality of life.

When it came to symptoms, members of this group scored an average of 50% better compared to the group who did not exercise or follow the diet.

Those who had either been part of the exercise-only group or the diet-only group still scored 30% better than the group who did neither.

"People with asthma sometimes find exercise challenging and this can lead to an overall deterioration in their fitness. Our study suggests that non-obese asthma patients can safely take part in well-planned, high-intensity exercise.

"It also shows that exercise combined with a healthy diet can help patients control their asthma symptoms and enjoy a better quality of life," Dr Toennesen explained.

She said that these findings are important because many patients do not have good control of their symptoms, which can impact their quality of life.

"We know that many patients are interested in whether they can improve their asthma control with exercise and a healthy diet. Our research suggests that people with asthma should be encouraged to eat a healthy diet and to take part in physical activity," she added.

These findings were presented at the European Respiratory Society International Congress 2017 in Milan, Italy.