During the first year of life, breastfeeding could help protect children with genetic profiles linked to asthma from developing respiratory symptoms such as asthma attacks, according to a study presented Sept. 4 at the European Respiratory Society's International Congress.

The beneficial effects of breastfeeding on the development of children's immune systems are already widely established. This new study, from the University Children's Hospital Basel and the University of Basel, Switzerland, adds to the wealth of research in the field by identifying protective effects of breastfeeding against respiratory symptoms linked to asthma, such as wheezing and asthma attacks.

The researchers studied 368 infants who had a genetic profile linked to asthma, with specific genetic variants on chromosome 17, called 17q21. Children with these genetic variants are at greater risk of developing a wheeze, particularly when exposed to other environmental factors or triggers, such as dust, pollen, animal hair, dust mites or airborne pollution, including atmospheric pollution and cigarette smoke. Certain foods and food additives, such as sulfites, can also be problematic, as well as certain medications (aspirin and other non-steroid anti-inflammatory drugs, beta-blockers).

Here, the scientists investigated whether breastfeeding could have a modifying effect on the specific genetic risk.

They found that, during the time that they were breastfed, children carrying the asthma risk genotype had a 27 per cent decreased relative risk of developing respiratory symptoms.

The infants who were not breastfed showed an increased risk of developing respiratory symptoms.

Asthma is a chronic condition characterized by the inflammation of the airways in the lungs. Symptoms include difficulty breathing, shortness of breath, wheezing and chest tightness. Eighty percent of people with asthma also suffer from allergic rhinitis or sinusitis. An estimated 300 million people worldwide suffer from asthma.

The study was presented at the European Respiratory Society's International Congress, which runs Sept. 3-7 in London.