Does common cold cause asthma?

US researchers studied more than 250 newborns at high risk for asthma and followed them from birth to 6 years old to investigate the relationship between specific childhood illnesses and early development of asthma. Samples of mucus from their nose and throat were taken and analysed and they were tested for specific viruses during wheezing illnesses.

Researchers found that nearly 90% of the children wheezing with common cold virus, rhinovirus (RV) at age 3 subsequently developed asthma at age 6. The lead author wrote in the Americam Journal of Respiratory and Critical Care Medicine that rhinovirus which causes wheezing in childhood was the most significant predictor of the subsequent development of asthma at age six.

Critics say that athough the study demontrated an association between wheezing during childhood colds and later asthma, it does not mean that cold is the casue of asthma. Asthma is a very difficult condition to diagnose but asthma at age six does not necessarily mean that the it will persist into later childhood.

Source: "Jackson DJ, Gangnon RE, Evans MD, et al. Wheezing Rhinovirus Illnesses in Early Life Predict Asthma Development in High-Risk Children." Am J Respir Crit Care Med 2008: 178; 667–672 ( abstract only)

Does regular use of paracetamol cause asthma?

The findings of a multi-centre study involving 1,028 participants across Europe suggested that using paracetamol at least once a week increases the risk of asthma.

Half of the participants were recruited as cases of self-reported diagnosis of asthma and half were healthy volunteers with no diagnosis of asthma as control. They found that cases were about 2.5 - 2.9 times more likely to have taken paracetamol regularly than controls but they did not find any association between use of other painkillers and asthma. The researchers said "there is now a need to carry out suitable intervention studies to determine whether the link is causal".

Critics say there are problems with this study - eg a case-control study cannot prove causation and cannot rule out that asthma causes people to take more painkillers. It was suggested that a randomised controlled study of healthy participants to paracetamol or not will produce more conclusive results.

Source: "The relation between paracetamol use and asthma: a GA2LEN European case-control study". European Respiratory Journal 2008; Published online before print June 25

Fish oil supplements may reduce asthma risk

A newspaper reported a trial that gave women fish oil supplements during their third trimester and compared the effects on their child’s health with olive oil capsules or no supplements.

Researchers found that the children of those mothers taking fish oil supplements were about 60% less likely to have asthma 16 years after the study began and concluded that their results suggest that fish oils intake in the third trimester may protect the offspring against asthma, however they said there is a need for large randomised controlled trials to examine this further.

Source: "Fish oil intake compared with olive oil intake in late pregnancy and asthma in the offspring: 16 y of registry-based follow-up from a randomized controlled trial." Am J Clin Nutr 2008; 88:167-175

Aspirin can cut asthma in women

The Telegraph reported a study that found aspirin could cut the risk of asthma in women by 10%.

The study was based on a randomised controlled trial involving 37,270 female health professionals who took either 100 mg of aspirin every other day or a placebo. The participants completed questionnaires over a 10 year period, which included a question relating to newly diagnosed asthma. The results showed a 10% fewer cases of asthma with aspirin use. The researchers said that the results might not apply to all women.

Source: "Randomised Aspirin Assignment And Risk Of Adult-Onset Asthma In The Women's Health Study". Thorax 2008 March 13 (epub ahead of print)

Household cleaning sprays raise asthma risk

A study of more than 3 500 people from 10 European countries found using household cleaning sprays and air fresheners as little as once a week raised the risk of asthma.

Researchers found that cleaning sprays, such as air fresheners, furniture cleaners and glass-cleaners had a particularly strong effect.

Source : "The Use of Household Cleaning Sprays and Adult Asthma: An International Longitudinal Study" Am. J. Respir. Crit. Care Med. 2007; 176(8) : 735-741