Nutrition Experts Urge: Wait Out the Winter with Frozen, Canned Vegetables and Fruits

American Institute for Cancer Research
Monday, 31 January 2000

Packaged Products Offer Same Nutrition, Cancer Protection as Fresh Produce

Under some circumstances, frozen and canned produce can be fresher than fresh, according to experts at the American Institute for Cancer Research (AICR). The Institute urges the public to maintain consumption of vegetables and fruits throughout the winter months by integrating frozen and canned fruits and vegetables into the diet.

Research has shown that frozen produce retains more beta-carotene, because it is protected from light by packaging. Frozen spinach, for example, typically contains about 80% more beta-carotene than fresh spinach, which loses the nutrient in shipment and while sitting in the produce aisle.

In some cases, canned fruits and vegetables also enjoy nutritional advantages over fresh produce. Fresh tomatoes contain lycopene, a powerful antioxidant now being studied for cancer-fighting potential. Yet processed tomato products - canned, jarred, or in sauces - contain much higher levels of available lycopene. Additionally, levels of vitamin C rise sharply when ascorbic acid is added to both frozen and canned products to retain color.

But the real value of frozen and canned produce is that it supplies the full nutritive value of fruits and vegetables during periods when fresh produce is expensive or less available. And AICR experts say that getting enough fruits and vegetables - whether fresh, frozen or canned - is too vital for overall health and disease prevention to occur only nine months of the year.

"Today, frozen and canned vegetables and fruits are the best dietary supplements you can take when fresh produce is unavailable," said Melanie Polk, M.M.Sc., R.D., Director of Nutrition Education at the Institute. "Flash freezing and other new technologies trap nutrients and phytochemicals immediately after harvest, while the produce is at its peak."

It's those nutrients and phytochemicals that lend fruits and vegetables the disease-fighting, health-promoting edge observed in research. "The science is clear: five or more servings of fruits and vegetables a day reduces the risk of cancer. That's true in July, when it's easy to take advantage of well-stocked groceries and farmers' markets. But it's equally true in January and February, when pickings in the produce aisle are slimmer. So when fresh produce is expensive or hard to come by, consumers should look to the many frozen and canned options at hand."

The Three-Day Rule

AICR experts stress that getting the full nutrient value of fresh vegetables and fruits requires careful selection and storage as well as timely consumption. Per capita, Americans throw away almost $250 dollars worth of spoiled fruits and vegetables each year.

"So here's a rule of thumb," said Polk. "When you walk down the produce aisle, buy as many fresh fruits and vegetables as you expect to use in about three days. After about three days of sitting in your pantry or refrigerator, many fresh produce items lose enough nutritive value that you're better served by frozen and canned alternatives."

Fresh apples, oranges, carrots and grapefruits are examples of foods that tend to maintain their nutritive value longer. Others, including kale, broccoli and green beans, she said, may fade more quickly.

What to Watch Out For

Experts caution that consumers also need to choose their packaged produce carefully. Many frozen and canned vegetables contain sauces with added fat and sodium. Similarly, if fruits are packed in heavy syrup, their sugar content soars.

In recent years, in response to consumer demand, processors have made packages and cans of low-fat, no-sodium-added vegetables increasingly available. Also on market shelves are canned fruits packed in "light" juice with no sugar added.

In fact, the Food and Drug Administration ruled in 1998 that makers of canned and frozen produce may include the word "healthy" on food labels if the contents are low in fat, sodium and cholesterol. This means that only products made without sauces, oils, syrups, brine or other additions can be labeled "healthy."

Regarding food safety and quality, most Americans know that cans that are damaged or misshapen should be avoided. Bulging cans may indicate spoilage.

Frozen fruits and vegetables should move about freely in the package. If they've fused into solid block of ice, some nutrient loss has already occurred. Also, if the package is sweating or has become stained by its contents, these are signs that the product has partially thawed and re-frozen on its way to the shelf.

Evidence is Clear

Results compiled in the landmark AICR report, Food, Nutrition, and the Prevention of Cancer: A Global Perspective, provide strong evidence for the protective power of fruits and vegetables. This document, published in 1997, analyzed over 4,500 studies into the link between diet and cancer. It represents the first truly international effort to find consensus in this rapidly growing field of study.

The report indicates that if the only change people made to their lives was to eat five or more servings of fruits and vegetables each day, worldwide cancer rates would drop by 20%. That works out to 2 million more lives untouched by cancer, this year alone.

"The AICR report illustrates that cancer risk is largely determined - up to 70% - by the everyday dietary and lifestyle choices we make. What we eat, how we eat it, and whether or not we exercise, manage our weight, drink alcohol or smoke - these things make the difference," Polk said. "That's another reason consumers should supplement their regular intake of fresh fruits and vegetables with frozen or canned produce. They're powerful tools that make the everyday fight against cancer faster, easier, and more flavorful."

For more information, or to contact American Institute for Cancer Research, see their website at: www.aicr.org