A new study of US and Canadian teenagers suggests that not getting enough essential nutrients in their diet is linked to risk of developing respiratory conditions such as asthma and poorer lung function.
The study is published in the July issue of the journal Chest.
Lead author, Dr Jane Burns of the Harvard School of Public Health, said in a prepared statement that:
“Our study, as well as other research, suggests that higher intakes of antioxidant and anti-inflammatory micronutrients are associated with lower reports of cough, respiratory infections, and less severe asthma-related symptoms.”
“Teenagers who have low dietary intakes of fruit, vitamin E, and omega-3 fatty acids are at greater risk of having asthma, emphasizing the importance of a balanced diet, composed of whole foods,” she added.
The researchers, who include scientists from the Harvard School of Public Health, Health Canada, Brigham and Women’s Hospital, and the Environmental Protection Agency (EPA) studied over 2,000 students in their 12th grade from 12 communities in the US and Canada.
The students filled in questionnaires about their respiratory health and diet. The questions also covered use of medication, smoking behavior, and exercise. Their lung function was then tested.
Most of the participants were white, 33 per cent were overweight, 72 per cent did not take multivitamins, and 25 per cent said they smoked every day.
Analysis of the questionnaires showed that at least 33 per cent of their diets had below the recommended daily levels of fruit, vegetables, vitamins A and E, beta-carotene and omega-3 fatty acids.
Burns said they looked at teenagers because this was an ideal age at which to test lung capacity and look at eating habits:
“During late adolescence, physical stature has, on average, been attained and lung growth closely parallels this growth. Therefore we were observing a time when lung function was close to its optimal capacity.”
“Also, although our diet survey targeted eating habits only during the past year, it did give us some idea of the teens’ general past diet. However, their current respiratory health may be a reflection of diet during childhood, as well as during the past year,” she added.
Vitamin supplements can help teenagers to reach their daily recommended targets, and “surprisingly, even relatively low levels of omega-3 fatty acids appeared to protect teens from higher reported respiratory symptoms,” said Burns.
The results showed that low consumption of fruit, vitamins C and E, and omega-3 fatty acids was linked to reduced lung function and greater risk of asthma, symptoms of chronic bronchitis and wheezing. These risks were greater among participants with the lowest consumption of these nutrients and who also smoked.
Reflecting on their findings Burns concludes:
“The most important thing to remember is that diet can have a significant impact on teens’ respiratory health. I would encourage them to make healthy eating a part of their daily routine, and stress to them that smoking is bad.”
Dr Mark J. Rosen, President of the American College of Chest Physicians commented on the research in a press release:
A balanced diet is not only good for lung health, but for general health.”
“Parents and physicians should work together to monitor and maintain healthy diets and lifestyles for children of all ages,” he added.
The researchers suggested more use could be made of fresh fruit as a daily snack and that a daily simple nutritious family meal helps teens to get their essential nutrients and improves family communication.
“Low dietary nutrient intakes and respiratory health in adolescents.”
Jane S. Burns, Douglas W. Dockery, Lucas M. Neas, Joel Schwartz, Brent A. Coull, Mark Raizenne, and Frank E. Speizer.
Chest, Prepublished online May 2, 2007 DOI:10.1378/chest.07-0038
Click here for resource on how to Eat a Variety of Fruit and Vegetables Every Day (from the CDC).
Written by: Catharine Paddock
Writer: Medical News Today