Summer weekend mornings in many American cities have come to mean farmers markets, and the way things are going this year will likely see a bumper crop of new markets. According to the USDA, the number of these local-food hubs nationwide has grown astronomically over the last 20 years: from 1,755 in 1994 to 3,706 in 2004 to an astonishing 8,283 in 2014. The USDA thinks this increased demand for regional produce items might be linked to “consumer perceptions of their freshness and quality.”
There’s plenty to like about farmers’ markets. It’s fun to see what’s in season, and to actually put your hands on the colorful and often muddy produce trucked in straight from the farm. But there’s a downside: Farm-fresh fruits and vegetables don’t stay fresh for long. Fortunately, the shelves at the supermarket are filled with produce that’s just as nutritionally sound as the stuff piled in crates at the farmer’s market. In fact, some canned goods contain more nutrients than their fresh counterparts.
“The nutritional content of canned food is comparable to fresh,” says Steven R. Miller, a professor of agricultural, food and resource economics at Michigan State University. Miller explains that as soon as a fruit or vegetable is picked, it starts to degrade — and doesn’t stop until the moment it is consumed, canned or frozen. A stalk of corn that’s picked and transported to market, then placed on a table until it’s finally taken home and eaten, may experience days of degradation between harvest and consumption. Corn in a can usually goes straight from the field to the cannery for processing within a day or two.
“Even if it has degraded a bit at the time of processing, there is no further degrading in the can,” says Miller, who published a study in 2014 (funded by the Can Manufacturers Institute) showing that canned foods were nutritionally comparable to fresh — and more economical to boot. “Since fresh foods degrade up to the time they are eaten, cans can sometimes have higher levels of nutritional content.”
Plenty of studies over the past 20 years have confirmed this. The University of Illinois made quite a buzz in 1997 when it published research showing that the 35 canned fruits and vegetables they studied for nutrient data were comparable to their fresh counterparts. This study, in part, helped persuade the FDA to allow cans to carry labels deeming their contents healthy.
“The stamp of approval from the FDA confirms what we’ve known all along; you can count on the nutritional quality of canned food,” Barbara Klein, a former professor of food science and nutrition at the University of Illinois at Urbana and the study’s author, said at the time. “But, even with the FDA decision, consumers are not aware that the canning process allows food producers to pick fresh foods at their peak, and pack them immediately to preserve both the flavor and the high nutrient content.”
The word “processed” often scares people, Miller says, but he explains that as far as canning is concerned, it simply means that a food is placed in the can and then heated to a high level to block oxidization from occurring. “The heating process does not degrade nutritional content, as some may think,” he says. “The whole point is to lock in quality at that point.”
Miller also notes — and his study affirms — that cans are much less expensive than buying fresh.