Thank you for bringing to light what you call the "Grocery Gap." A more appropriate term is "Food Desert." It's not just about bruised bananas - this is a life-and-death issue that requires more attention.
Every year, thousands die from diabetes. The Black community is probably the hardest-hit. It was the sugar industry which drove the slave trade, and now it is the sugar industry which is killing the descendants of those slaves through diabetes (including some of our family).
Diabetes cannot be cured, but it can be controlled by diet. I know, as I have Type 2 Diabetes, and have completely controlled it through diet (thanks to my wife). I am lucky. I can find the foods I need to eat easily in our neighborhood, including fresh greens, raw nuts and organic produce. But if I go to my in-laws in South LA, I cannot find the food I need in that neighborhood to control my diabetes. There is, however, plenty of sugar and starch to send my glucose levels into a frenzy.
Nor is it just an issue of lack of Trader Joe's. Even the same chain will have disparate products, prices and quality. In my own un-scientific comparison between the Ralphs in West LA and the Ralphs in Inglewood, I found less produce, of lower quality, but higher prices in Inglewood.
There are some people trying to do something about this. One is the pop-up Süprmarkt providing organic produce in South LA.
