According to the study, conducted for LaSalle Bank, the average white resident in Chicago lives .39 miles from a grocery store and the average black resident .59 miles. Therefore, the premise of the study is that African-Americans are more likely to eat at fast-food restaurants rather than partake in healthier choices at a grocery store.
Right up front the story quotes the author's study as saying that the grocery store-disease connection is there, but one doesn't cause the other.
Mari Gallagher, the consultant who conducted the study for LaSalle Bank, stops short of saying there is a cause-and-effect relationship between living in a food desert and developing a disease.So, in other words, the entire story is essentially like discussing why cities starting with the first half of the alphabet have a higher crime rate than cities starting with the second half of the alphabet. There may be a statistically significant correlation with lower letters and higher crime rates, but if one doesn't cause the other, the relationship is coincidental, and the discussion scientifically pointless.
It's quite obvious to everyone but the Tribune that the higher incidence of diseases is caused by something other than a .2 mile difference in proximity to grocery stores.