Are You Getting the Nutrients You Pay for at the Grocers?
There are a lot of reasons to like local food: less environmental impact of transporting food, keeping dollars in the local economy, fresher tasting food, etc. One of the most important could be the nutritional quality of the fresh produce you are buying. We eat things because we like the taste and because we want to be healthy. Most people would say they are trying to eat a healthier diet and that, of course, includes fruits and vegetables. But what if 80% of some of the key nutrients were gone by the time you purchased those vegetables?
It is pretty well accepted that produce loses nutrients after harvest, leading to debates about whether canned or frozen or fresh vegetables retain the most nutrients. I’m not going to get into that debate today. What I really want you to consider is how you can get the most out of the fresh produce you buy. A 2003 study published in the Journal of Agriculture and Food Chemistry compared fresh broccoli with broccoli that was handled to mimic the typical refrigerated storage,transportation and retail display time of broccoli harvested, transported and displayed at a grocery store.
At the end of the experiment:
“Results showed major losses at the end of both periods, in comparison with broccoli at harvest. Thus, the respective losses, at the end of cold storage and retail periods, were 71-80% of total glucosinolates, 62-59% of total flavonoids, 51-44% of sinapic acid derivatives, and 73-74% caffeoyl-quinic acid derivatives. Slight differences in all compound concentrations between storage and retail sale periods were detected. Distribution and retail periods had minimal effects on vitamin C.”
Wow! Only vitamin C was minnimally affected. Glucosinolates are among the cancer fighting compounds that cruciferous vegetables are credited with. Just think, 80% of these compounds are probably lost by the time the broccoli gets to the store! This is where local food and farmer’s markets shine! Most produce at a farmer’s market is less than 24 hours old!! Some farmers markets allow farmers to supplement their business by buying produce from other producers or even at produce auctions and reselling it so to insure the freshest produce, buy from the farmer who grew it.
Does this mean that all produce in the store has lost most of it’s nutrient value? No. This is only one vegetable and one study. However, I was shocked to see how great the loss of nutrients was. Here is another study that shows 55% loss of a key cancer fighting nutrient in broccoli within 3 days. It is probably safe to say that shopping the farmer’s market twice a week and eating the produce you buy within a few days is the best way to get the most nutrient dense produce. If we based our shopping decisions on price per nutrient rather than price per pound we would understand a more accurate cost of food. (Okay, I understand that fat and carbohydrates and sugar are also considered nutrients but you know what I mean) Another way to evaluate what we are getting for our food dollars is to think about nutrients per calorie in what we are buying/eating. In my experience, prices at the farmer’s market for most vegetables (tomatoes are a possible exception) are no more expensive than at a supermarket (sometimes less).
On a side note: One of the reasons we sell living microgreens is so that you can get the best nutrient density possible. Since they aren’t “harvested” until you cut them, they have peak nutrient density.
Next time you see that your produce is from Mexico, Chili, or California, consider how far that produce has traveled and the time it takes to harvest, pack, ship, unload at a warehouse distribution center and then be moved to your local store. If your produce has more miles on it than a used car, it has probably lost nutritional value along the way. Buy Local, Eat Local if you can.