Over-consumption of soft drinks has been associated with tooth decay and obesity for decades. Now, a recent University of Adelaide study has unearthed even more reason for concern. According to university researchers, soft drinks appear to be linked to lung disease and asthma. What is the connection?

Natural health practitioners almost universally recommend herbal teas, natural sweeteners, water and fruits and fruit juices as a healthy alternative to soft drinks. They cite the high levels of refined sugars, artificial flavours, colours and other chemical additives as being responsible for a host of diseases and allergic reactions. Now it seems that scientific methodology is backing up their position. The University of Adelaide surveyed 16900 people and discovered that there was a direct correlation between consumption of over 500ml of soft drinks and the incidence of asthma and chronic obstructive pulmonary disease (COPD), a serious disorder that causes blockages in airways.

While the researchers were unable to pinpoint the reasons for the correlation, they hypothesised two possible reasons:

1. High concentrations of sugar made the lungs and airways more susceptible to inflammation due to allergic reactions.
   
   
2. The preservatives in soft drinks may cause allergic reactions that result in asthma and COPD

The Links between Asthma, Allergies and Chemicals

There are long established links between outbreaks of asthma and allergies and a number of substances, both natural and artificial. Asthma sufferers are often cautioned to remove carpets from their floors and keep their pets outdoors because of the dangers posed by dust mites and pet dander. Many people have allergic reactions to some pollens and seasonal outbreaks of asthma and other respiratory disorders are commonplace. The establishment of links between chemical additives and pulmonary allergic reactions has been slower to be recognised, though, but direct links between chemical ingredients found in common products such as perfume (including perfumed soaps, deodorants, etc.) and dermatitis have been established.

It stands to reason, then, that the consumption of chemical additives such as those found in the preservatives in soft drinks would be linked to asthma and COPD. According to University of Adelaide researchers as quoted in the Age and the Sydney Morning Herald, this was "the first large population study showing an association between soft drink consumption in relation to asthma/COPD." 

How Many Soft Drinks is Too Many Soft Drinks?

The average can contains around one-third of a litre of soft drink. The University of Adelaide study discovered a connection between the consumption of over half a litre of soft drinks and asthma and COPD, which would suggest that more than one can per day was too many soft drinks. However, the study was conducted amongst the adult population, which would indicate that children who consumed as little as a single can per day may be at risk. Parents may be wise to consider replacing soft drinks with water and non-sugary drinks in their children's diets as much as possible as a precautionary measure. Parents of children with a history of asthma or pulmonary disease may want to consult a holistic doctor or specialist and discuss the issues surrounding the links between these diseases and soft drinks. While the verdict is not in, the evidence is strong and, as the saying goes, "an ounce of prevention is worth a pound of cure."