Sweet corn is generally grown on a smaller scale, sold locally, and eaten fresh, avoiding the environmental costs of processing and transportation.
In 2023, sweet corn made the Environmental Working Group’s Clean Fifteen list of the 15 crops with the lowest amount of pesticide residue.
Culinary Medicine
By Mary B Grosvenor, MS, RD and
Summer is a time of abundant fresh produce but not too many vegetables have their own season. “Corn season” is that special time when sweet corn is ripe and readily available at farm stands, farmer’s markets, and grocery stores. Unfortunately, this summer treat has a bad reputation. Some of this stems from its high carbohydrate content, which people associate high blood sugar and weight gain. And some is related to corn’s impact on the environment. But it is so delicious and fun to eat! Is it OK to enjoy some corn on the cob?
Corn, also known as maize, was domesticated in southwestern Mexico more than 8700 years ago. Today it is grown on every continent except Antarctica with the United States being the world’s largest producer. [1] While botanically corn is a fruit, in our diets it has been categorized as both a vegetable and a grain depending on when we pick it and how we process it. The corn you munch off a cob is considered a starchy vegetable; it is picked when the kernels are sweet and juicy. Field corn, which accounts for most of the corn in the US, is considered a grain; it is picked when the kernels are hard and can be ground into corn meal and corn flour.
Whether eaten as a vegetable or a grain, corn provides protein, carbohydrate, fiber, potassium, and B vitamins and is a good source of the phytochemicals lutein and zeaxanthin, which promote eye health. An ear of fresh corn provides 17 grams (g) of carbohydrate, 2 g of fiber, 3 g of protein, and about 80 Calories. The high carbohydrate content of corn has the potential to raise blood sugar and promote weight gain. However, the fiber and protein in corn slow its digestion. This blunts the rise in blood sugar that occurs after eating and helps you feel full longer. The fiber in corn also feeds the good bacteria in your gut and helps prevent constipation. This in turn can help manage blood sugar and weight, regulate blood pressure, and improve overall heart health. [2]
Corn’s environmental impact depends on how and where the corn is grown and the extent to which it is transported and processed. An evaluation of field corn shows that it is costly to grow in terms of both water and land use. It is also typically genetically engineered and grown as a monoculture crop. [3]. While the issue of genetic engineering is contentious, in the case of corn, genetic modification has increased crop yields and allowed for a reduction in pesticide use, helping to decrease greenhouse gas emissions. [4] Monoculture farming grows a single crop in the same location over many years; this practice reduces biological diversity and contributes to soil depletion. However, it can also reduce the financial and ecological costs involved in planting and harvesting. [3] The environmental impact of most sweet corn is a simpler equation. Sweet corn is a delicate crop that requires lots of water but is less likely to be grown in monoculture and rarely genetically engineered. It is generally grown on a smaller scale, sold locally, and eaten fresh, avoiding the environmental costs of processing and transportation. [5] In 2023, sweet corn made the Environmental Working Group’s Clean Fifteen list of the 15 crops with the lowest amount of pesticide residue. [6]
So, relish some sweet corn. You can grill it, microwave it, broil it, or boil it. Try it with some cotija cheese and chili powder. Add it to soups and chowders. To minimize the environmental cost buy it locally and don’t waste what you can’t eat right away. Leftovers can be cut off the cob and used to make corn salsa to top burgers and flavor salads and casseroles. Or you can freeze it to enjoy when corn season is over.
Culinary Medicine: Ingredient Explainer - Corn
Get the healthy Corn Salsa Recipe
Sources
[1] Corn Production by State [Updated June2023] https://worldpopulationreview.com/state-rankings/corn-production-by-state# Accessed September 1, 2023
[2] Cleveland Clinic. Is corn good for you? August 2, 2023. Accessed September 4, 2023. https://health.clevelandclinic.org/benefits-of-corn/.
[3]Biswas D, Salaheen S. Organic Farming Practices: Integrated culture versus Monoculture. In: Safety and Practice for Organic Food. Elsevier Science; 2019.
[4] Abdul Aziz M, Brini F, Rouached H, Masmoudi K. Genetically engineered crops for sustainably enhanced food production systems. Front Plant Sci. 2022 Nov 8;13:1027828. doi: 10.3389/fpls.2022.1027828.
[5] Nargi L. The race to protect Sweet Corn. Cold Spring Harbor Laboratory. November 15, 2022. Accessed September 4, 2023. https://www.cshl.edu/the-race-to-protect-sweet-corn/.
[6] Group EW. EWG’s 2023 Shopper’s Guide to Pesticides in Produce. EWG’s 2023 Shopper’s Guide to Pesticides in Produce | Summary. Accessed September 4, 2023. https://www.ewg.org/foodnews/summary.php#clean-fifteen.