Summary: It is long known that health disparities between various neighborhoods exist. Further, health data show a greater prevalence of gastrointestinal infections in low-income areas. However, experts have always assumed that these disparities are due to poorer hygienic conditions. This new research indicates that contaminated produce at supermarkets may be one of the contributing factors to these health disparities. It found exceptionally high contamination of 83% by staphylococcus aureus. Further, if found that certain pathogens like E. coli or Salmonella were only present in fresh produce sourced from supermarkets in low-income areas. Thus, it indicates issues with the supply chain of products, too.
Keywords: health disparities, low-income areas, contamination of fresh produce, pathogens in romaine lettuce
Health disparities and their relationship to socioeconomic factors are long known to science. It is well-known that gastrointestinal infections are more common in low-income areas, even in developed economies like the US. However, what is poorly understood is what leads to such differences1.
Finding the cause of these differences is not a straightforward task due to numerous existing disparities. Therefore, it is challenging to say which factor plays a greater role. This difference in health outcomes is perhaps a combination of multiple factors like lack of green spaces, less physical activity, higher risk of infections, a more dense population in low-income areas2.
A new study by the University of Houston sheds light on another lesser-known factor. It shows that even access to fresh produce and its quality differs significantly between the neighborhoods. To further demonstrate their finding, they analyzed the romaine lettuceavailable in low-income areas and compared it with high-income areas.
The results of this discovery were published in the Journal of Food Protection. This study has some unexpected results.One may understand that the produce may be less fresh in low-income areas, but a high contamination rate is least expected. In the study, researchers bought romaine lettuce from supermarkets in low-income and high-income areas. They found that romaine lettuce bought from low-income areas was contaminated with numerous pathogens. There was a considerable difference between the two samples3.
Unlike previous studies, this particular study was not focused on freshness or other qualities of the produce. Instead, they analyzed romaine lettuce for the presence of microbes that commonly cause gastrointestinal infection and other systemic infections like staphylococcus aureus, E. coli, Salmonella spp., and listeria monocytogenes.
The study found that staphylococcus aureus was present in 87% of samples collected from low-income areas and only in 38% in those collected from high-income sites.
Further, the results of RT-PCR showed that many common pathogens were only present in samples from low-income areas, like E. coli in 4%, Salmonella spp. in 53%, and listeria monocytogenes in 13%.
They think that there could be many reasons for these differences. As in many cases,the source of the produce may be similar. Thus, these differences could be due to poor sanitation conditions, the difference in temperature, cross-contamination. It is also more likely that low-income areas might be getting less fresh produce.
Although this study could find the difference between the quality of fresh produce in different income areas, it could not understand the underlying causes. Therefore, researchers think that there is a need to investigate the supply chain. Such contaminations may also occur because low-income areas may have delayed supply or possibly other causes.
Whatever be the cause, it clearly demonstrates that low-income areas have access to less nutritious food. Further, low-income neighborhoods are dotted with food points offering cheaper food options made from produce acquired at a lower price and of lower quality.
It may be just one of the factors for health disparities between low-income and high-income areas. However, if one combines numerous existing factors, things may sound alarming. It may ultimately result in much worse health outcomes in low-income areas.