A healthful diet consists of more fruit and vegetables, and less red meat.
Fruits, vegetables, and whole grains are the main components of a healthful diet, the benefits of which are hailed by medical researchers and nutritionists alike.
New research adds improved respiratory health to the list. According to a new study led by Roland Andrianasolo, from the Nutritional Epidemiology Research Team at INSERM — or the French National Institute of Health and Medical Research in Paris — healthful eating may help to reduce the frequency of asthma symptoms and improve a person's control of them.
He explains the motivation for the study, saying, "Existing research on the relationship between diet and asthma is inconclusive, and compared to other chronic diseases, the role of diet in asthma is still debated."
"This has resulted in a lack of clear nutritional recommendations for asthma prevention," he goes on, "and little guidance for people living with asthma on how to reduce their symptoms through diet."
"To address this gap, we wanted to make more detailed and precise assessments of dietary habits and the associations between several dietary scores and asthma symptoms, as well as the level of asthma control," says Andrianasolo.
Studying the link between asthma and diet
To make this precise assessment, Andrianasolo and his colleagues examined the data of 34,776 French adults who participated in the 2017 NutriNet-Santé study.
As part of the study, the participants answered detailed questions about their respiratory health — specifically, it ensued that 25 percent of men and 28 percent of women had at least one asthma symptom.
The participants also reported on the frequency of their symptoms over a 1-year period and answered questions about their control of asthma symptoms over the course of 4 weeks.
These included questions about the use of emergency medication as well as the degree to which asthma symptoms interfered with daily activities.
The quality of the participants' diets was assessed using three 24-hour dietary records that were collected randomly from each participant. Additionally, the participants' nutrition was assessed using three dietary scores.
Overall, a healthful diet was considered to be high in fruit, vegetables, and whole grains.
A high intake of meat, salt, and sugar was thought to be unhealthful.
Healthful diets may prevent, manage asthma
On the whole, the study revealed that men who adhered to a healthful diet were 30 percent less likely to experience asthma symptoms. For women, the likelihood was 20 percent lower.
Also, the men who ate healthfully were 60 percent less likely to have poorly controlled asthma, while women who stuck to a healthful diet were 27 percent less likely to have poorly controlled symptoms.
Andrianasolo weighs in on the findings, saying, "This study was designed to assess the role of an overall [healthful] diet on asthma symptoms and control, rather than identify particular specific foods or nutrients."
"Our results strongly encourage the promotion of [healthful] diets for preventing asthma symptoms and managing the disease."
"A [healthful] diet, as assessed by the dietary scores we used, is mostly made up of a high intake of fruit, vegetables, and fiber. These have antioxidant and anti-inflammatory properties and are elements in a [healthful] diet that potentially lower symptoms."
"In contrast, [...] meat, salt, and sugar [...] are elements with proinflammatory capacities that may potentially worsen symptoms of asthma," explains Andrianasolo.
He concedes that further studies are required to confirm the findings. However, he says, the new results "contribute to evidence on the role of diet in asthma, and extend and justify the need to continually support public health recommendations on promoting a [healthful] diet."
Prof. Mina Gaga, the president of the European Respiratory Society, also comments on the findings, saying, "This research adds to the evidence on the importance of a healthy diet in managing asthma and its possible role in helping prevent the onset of asthma in adults."
"Healthcare professionals must find the time to discuss diet with their patients, as this research suggests it could play an important role in preventing asthma."