Fresh, Canned or Frozen Produce?
Unless you're picking fruits and veggies yourself, there might not be much difference nutritionally.
There's nothing quite like eating a handful of freshly picked blueberries on a warm summer day, each bite bursting with flavor and inflammation-fighting polyphenols, bone-building minerals and must-have vitamins. Surprisingly, you can get nearly the same nutrition from a bag of frozen blueberries.
Despite what you might have heard, fresh produce may not be more nutritious than frozen produce. Even canned fruits and veggies are a good source of many of the nutrients found in the produce section of your grocery store.
“Nutrition is not always as straightforward as you'd like it to be,” says Gene Lester, a U.S. Department of Agricultural plant physiologist who specializes in the nutritional content of plants and fruits.
Many things factor into produce's nutritional makeup – the soil it’s grown in, when it's picked, how it’s preserved and even the way a vegetable or fruit is prepared. One thing is very clear: The nutritional value of fruits and vegetables is unparalleled.
Fruits and vegetables are rich in important vitamins and minerals and a good source of dietary fiber, which increases satiety and helps put the brakes on overeating, helping control excess weight that adds to pressure on painful joints. And many contain nutrients that may help fight inflammation associated with inflammatory forms of arthritis, such as rheumatoid arthritis (RA).
For example, butternut squash and pumpkin contain beta-cryptoxanthin, which a study in the August 2005 issue of American Journal of Clinical Nutrition linked with reduced RA-related inflammation. Antioxidants in the squash, including vitamin C, also help fend off inflammation.
“One of the key nutrients that play a vital role in risk reduction [of RA inflammation] is vitamin C in foods like broccoli, strawberries, citrus fruit, peppers, cabbage, collard greens, melons, potatoes and tomatoes,” says registered dietitian Angela Ginn, senior education coordinator at the University of Maryland and a spokesperson for the Academy of Nutrition and Dietetics.
Are nutrients in frozen and canned fruits and vegetables on par with fresh produce? It depends.
Diane M. Barrett, PhD, a fruit and vegetable products specialist in the University of California, Davis’s Food Science and Technology department, notes that frozen produce could actually have a leg up on imported offerings, which may lose some nutritional value through transport and storage.
“When fruits and vegetables are allowed to ripen to their peak eating quality before being harvested and then quickly frozen to lock in their nutrients, flavor and color, they may be superior,” Barrett says.
Commercial fruits and veggies are often picked before they reach their nutritional peak, so that they can ripen while in transit. In contrast, frozen fruits and vegetables are often picked at a more mature state and then flash frozen. Canned vegetables go through a similar process, sealing in many nutrients. Here are a few frozen and canned selections that might surprise you:
- Raspberries. Scientists discovered that levels of antioxidants, including vitamin C, polyphenols and anthocyanins, are about the same in frozen raspberries as fresh.
- Green peas. Research found that freezing peas helps preserve vitamin C levels that fresh peas quickly lose after being harvested.
- Peaches. Canned peaches in light syrup have more vitamin C than their fresh counterparts.
- Spinach. Cup for cup, frozen, chopped spinach actually contains higher concentrations than fresh spinach of a range of nutrients, including folate, vitamin E, vitamin A, vitamin K and calcium. These nutrients build stronger bones and lower the risk of hypertension. (Hypertension raises the risk of cardiovascular disease, which is already higher in people with RA than other people.)
Still, the preservation methods are not without their drawbacks.
Some important nutrients like B vitamins and vitamin C are water-soluble; in canned goods, those vitamins leach into the packing water. Exposure to air and light – either in your fridge or in a fruit bowl on your kitchen counter – can also limit the shelf life of some vitamins. But other nutrients – including vitamins A, D, E and K, and fiber – survive this process.
The important thing is to eat more vegetables and fruit, whether they’re canned, frozen or fresh. Not only do they deliver in nutritional value, they can replace less healthy choices that people make, says Lester. “The more mouthfuls of vegetables you eat, the [fewer] mouthfuls of fattier foods you’ll eat.”