Perhaps you consider yourself a socially and environmentally responsible individual. You separate all your recyclables, turn off the water when you brush your teeth, and buy shampoo packaged in post-consumed plastic. Now, you are about to sit down to a well-earned fresh fruit salad of papayas, strawberries, and grapes. But, the papayas are from Mexico, the strawberries are imported from Ecuador, and the grapes are from Chile. How environmentally responsible is it if your food has traveled a greater distance than you have on any particular day? And how has this travel affected the nutritional content?
From Field to Table
It's been estimated that food eaten in this country travels an average of 1,500 miles from the farm to the dinner table. This is an economic and environmental concern. At this rate, fuel and local agricultural resources could run out for future generations.
One step you can take is to get a year-round guide to local fresh produce, which can be obtained from your state's Department of Agriculture. However, in much of the winter and early spring, the only local fresh produce available in northern latitudes falls in the apple, pear, root vegetable, cabbage, onion, or squash families. If you want other types of fresh produce at this time of year, one option is to can or freeze produce when it is in season. In order to do this, however, you need canning and freezing equipment and an in-depth knowledge of sanitation and storage techniques.
There is another, simpler alternative. The act of navigating your grocery cart through the canned and frozen produce section of your market can help save the earth and improve your nutrition. Frozen fruit and vegetables are shipped directly from the fields and orchards in which they are grown to a processor near the field. After they have been frozen or canned, they are preserved at the processor until a large bulk shipment can be made. Perishable fresh produce, on the other hand, needs to get to its destination quickly and must be shipped in smaller amounts and great distances, especially off-season. As mentioned, this is an uneconomical process.
Fresh produce is shipped quickly enough to prevent spoilage. But, its nutrient content may be compromised. The longer fruits and vegetables are in transition, the more nutrients are oxidized into the air. The average time from field to your fruit or salad bowl is about 10-14 days. In contrast, produce that is frozen or canned sits only a couple of hours before its freshness and nutrients are locked in by freezing or canning.
Nutrient Content Affected by Travel and Processing
The differences in the nutrition content of fresh versus frozen and canned foods are significant. For example, frozen green beans retain a high percentage of their vitamin C content. On the other hand, green beans that sit on a truck, wait on a loading dock at the supermarket, and then languish in your refrigerator, do not retain as much of their vitamin C content.
Ever notice your frozen strawberries or canned pumpkin may be months old but they retain their bold colors when you do decide to use them? The reason is that food processors often choose the brightest, most vivid colored produce right from the field. These fruits and vegetables are not only more pleasing to consumers, but also contain the greatest concentration of nutrients. These deeper hues signify a richer nutrient content.
The nutritional value of some foods is improved with canning. Lycopene, an antioxidant found in tomatoes, is actually enhanced by the canning process. Lycopene is found naturally in tomatoes, but is better absorbed by the body from canned tomato products such as tomato paste, sauce, and diced tomatoes.
The Drawbacks to Frozen and Canned Produce
One of the major drawbacks to using frozen or canned vegetables is that extra sodium and fat can sneak in. Those who need to watch their salt intake should look for low-sodium varieties of canned vegetables. Most vegetable-sauce combinations are high in fat, but you can create your own low-fat sauces with honey, flavored vinegars, herbs and spices, or low-fat cheeses. Although most frozen vegetables are packaged on the spot, you should check the label to be sure.
The Bottom Line
Summer is an excellent time to frequent local farmers' markets for fresh, non-transported produce. And in the winter, you can treat yourself to a sliced papaya for a little extra sunshine. Just think about canned, frozen, or locally produced options before you do, and avoid eating from the equator every weekday this winter. It is not just about saving natural resources—it is about your health and nutrition, as well as your wallet.
- Reviewer: Michael Woods, MD, FAAP
- Review Date: 04/2017 -
- Update Date: 05/02/2017 -