Fresh, Frozen and Canned Vegetables: Is There Really A Difference in Nutrient Levels?
We spoke to a registered dietician to get the low-down and you just may be surprised
Sunday, September 30, 2012
Having access to fresh vegetables is always wonderful and for some communities it’s even a privilege.
But is the extra cash you need to dole out for fresh produce really worth it. I mean, couldn’t you get the same nutritional value in canned and frozen vegetables?
According to a number of studies, fresh vegetables lose about half of their vitamins in just a matter of days after being harvested, if not properly chilled or sustained. And even after you refrigerate the veggies they still lose at least 50 percent of their nutritional value in about a week's time.
So unless you and your neighborhood rabbits are eating the stuff right out of the ground, you're going to lose quite a bit of the potential nutrition upfront.
The good news, according to Amy Jamieson-Petonic, a registered dietician and spokesperson for the Academy of Nutrition and Dietetics based in Cleveland, is that there is actually very little difference between fresh, canned or frozen vegetables, so consumers shouldn’t blindly plunk down extra money for fresh produce.
Picked at the peak
“Canned and frozen veggies (low-sodium versions) are picked and harvested at their nutritional peak, and can be much more economical for people trying to eat healthy on a budget,” she said in an interview with ConsumerAffairs.
“Many of my clients are trying to watch their food dollars closely. I suggest to my clients to choose local fruits and vegetables in season to get the most nutritional bang for their buck. It truly is a myth that eating healthy costs more money. For example, fruits and vegetables can be much cheaper than snack foods and processed foods, and your body will thank you in the long run,” she says.
But what about the sodium in canned foods? How should we differentiate between what’s beneficial and what’s being buried in a mound of unhealthy salt?
Of course you can just read the can’s label to determine sodium levels, but how much salt is just too much when it comes to eating the canned stuff?
“The USDA recommends less than 2,400 milligrams of sodium per day, and less than 1,500 milligrams if you have a history of high blood pressure,” says Jamieson-Petonic, who also explained that just one teaspoon of table salt has a whopping 2,500 milligrams of sodium.
“I recommend to purchase vegetables and drain them well under cold running water to rinse the salt off. The sodium should be negligible at this point,” she says.
Lost in canning
But canned vegetables also lose their fair share of nutrients once prepared and packaged.
According to the University of Minnesota, once canned veggies go through the necessary heating process to be packaged, about one-third to one-half of vitamins A, C, thiamin and riboflavin are lost. And about 5 to 20 percent of vitamins are removed after each year, depending on just how you’re storing the vegetables.
So if you compare the nutritional value that’s lost between canned and fresh vegetables, the numbers are pretty even, which proves the difference between the two types of veggies are very small.
Experts also say that buying fresh produce should be more for those consumers who routinely eat their vegetables, or already have a meal plan put together that incorporates them.
And when it comes to buying frozen, consumers should choose fruits and vegetables that are not already peeled, as many manufactures have to strip layers off the foods before they are packaged, namely carrots, tomatoes, and peaches, experts say.
Also, according to researchers from the University of California Davis, frozen products lose some of their nutrients in the beginning of packaging during the blanching process, as well as during long storage times, as oxidation eventually takes hold of the food, diminishing some of its nutrients.
Grow your own
Nutrition experts at Ohio State University suggest that people who grow their own veggies, should stick with those that are fresh, young, and tender. And if you plan to can or freeze them, you should do it within three hours after harvesting to maintain its peak health value.
So in short, there really isn’t much difference between fresh, canned or frozen vegetables when it comes to nutrients, as they all lose similar amounts of vitamins after being picked.
So for those consumers who are a bit cash-strapped, they shouldn’t at feel obligated to break the bank always trying to buy fresh produce, especially since the shelf-life is so short and the vegetables can easily be wasted.
And when it comes to preparing veggies for your meals, Jamieson-Petonic says it’s better to cook them sooner than later, and for those who believe nuking the vegetables will remove some of the nutrients, they need not worry. Using the microwave is actually one of the best ways to prepare vegetables.
“I would suggest cooking quickly to preserve the nutrients,” she said. "For example, microwaving or steaming will be better methods than boiling. Some nutrients, such as Vitamin C, are considered heat labile, meaning that the nutrients can be leached out in the cooking water, so the faster you can cook them the better.”