Produce is most nutritious shortly after harvesting, studies
show. But many fruits and vegetables on supermarket shelves
are sold days or weeks after they’ve been harvested and may
not be at their nutritional peak. But canned and frozen
foods are packed right after they’ve been harvested, sealing
in vitamins, nutrients, and other beneficial compounds. Plus
canned goods tend to cost less than fresh. And, in some
cases, canned foods have higher levels of key vitamins and
nutrients than even fresh varieties.
“Some fruits and vegetables are actually better when they’re
heated and some or not, so it depends on what you’re talking
about when you’re look at canned vs. fresh vs. frozen,” says
Marisa Moore, a registered Atlanta-based dietitian and a
spokeswoman for the Academy of Nutrition and Dietetics.
“For example, canned tomatoes have higher amounts of
[cancer-fighting] lycopene vs. fresh,” she tells Newsmax
Health. “Canned corn has more lutein, an antioxidant,
and heated canned carrots have more beta-carotene.”
Canned foods are also available year-round, just like frozen
foods, so you can always include a variety of fruits and
vegetables in your diet — another critical component to
healthy eating, Moore notes.
Numerous studies have found many fruits and vegetables have
as much or more nutrients, disease-fighting antioxidants,
and other nutritional substances, compared to fresh
varieties.
Cathy Kapica, a nutrition specialist at Tufts University,
put canned vegetables to the test in a recent market-basket
study that compared key nutrients and the costs in canned,
fresh, frozen and dried varieties of a handful of common
foods. The study — presented at a meeting of the
Experimental Biology scientific meeting — found that when
price, waste and preparation time are considered, “canned
foods almost always offered a more affordable, convenient
way to get needed-nutrients.”
Kapica tells Newsmax Health the findings may come
as a surprise to some consumers.
But she adds: “Yes, canned foods can be better choices than
fresh. There are numerous studies that support the
nutritional quality of canned foods. And foods, like fruit
and vegetables, are picked at the peak of ripeness and
packed soon after and close to the farms, preserving many
nutrients which might be lost in fresh during transport and
storage in stores and the home.”
Kapica explains that heating, chopping, and other cooking
techniques involved in the canning process “break up the
small-cell particles in foods, making their nutrients more
available for metabolism during digestion.”
For the study, Kapica and her colleagues analyzed the
nutrients in corn, green snap beans, mushrooms, peas,
pumpkin, spinach, tomatoes, pears, peaches, pinto beans and
tuna fish. Kapica sought to determine the cost of several
key nutrients, including protein, fiber, potassium, vitamin
A, vitamin C and folate.
Among the key research findings:
Pinto Beans. Canned pinto beans contain as
much protein and fiber as dried beans, but cost $1 less per
serving.
Tomatoes. Levels of lycopene, a beneficial
compound believed to reduce the risk of prostate cancer and
other health conditions, actually increase when tomatoes are
heated during the canning process.
Corn. Canned corn has higher levels of
lutein — a beneficial antioxidant that may reduce the risks
of cataracts and targets “free radicals” that can lead to
cancer and heart disease — than fresh corn. Canned corn also
offers the same amount of dietary fiber as fresh — at a 25
percent savings.
Spinach. Spinach doesn’t lose its vitamin
content when canned. Vitamin C levels are virtually the same
in fresh, frozen, or canned varieties. But canned spinach
provides the same levels of vitamin C at an 85 percent
savings over fresh or frozen.
Kapica said her study also found that canned tuna, pumpkin,
mushrooms, green beans, peaches and pears are also good
choices, when compared to fresh vegetables.
Other recent research has reached similar conclusions, among
them:
- A University of California-Davis study found that virtually all forms of fruits and veggies — canned, cooked fresh, and frozen — are nutritionally similar and can contribute to a healthful eating plan. But researchers also found fresh produce loses nutrients more rapidly than canned or frozen fruits and vegetables.
- An Oregon Health Sciences University study demonstrated increased amounts of some key anthocyanins — a powerful antioxidant — in canned blueberries, compared to the amounts in fresh and frozen blueberries.
- A U.S. Department of Agriculture survey found canned tomatoes, carrots, spinach, pumpkin, and corn are rich in antioxidants. One-half cup of canned tomatoes provides 11.8 milligrams of lycopene compared to 3.7 milligrams found in one medium uncooked tomato; heating of carrots and spinach for canning enhances the bioavailability of carotene; canned pumpkin contains a higher concentration of beta carotene than fresh.
“Consumers are not aware of the nutritional value of canned
foods,” Kapica notes. “Canned foods have been providing
nutrition and safety for over 100 years, and their use is
still relevant today. For those on tight budgets, or where
access to stores is limited, canned foods can be especially
important to meet nutrition needs.”
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