Written By:
Joy Diggs, MS, CPT, RD, LD
Certified Personal Trainer
Registered and Licensed Dietitian
When grocery shopping, it is always important to stock up on fruits and veggies, but which is the best choice, fresh, frozen, or canned? The short answer would be fresh BUT, in actuality, it depends! If you pick the produce right off the farm and eat it, fresh will always be the best choice. Since that’s normally not the case, which is the best choice?
Is fresh produce really fresh? Let’s discuss. Many fruits and vegetables only reach their peak nutritional content on the vine. Once they have been picked, the nutrition quality starts to decrease. This means, the freshness of a fruit or vegetable depends on the length of time between when it was harvested at the farm, how long it takes to reach the grocery store, how long it sits in the back of the grocery store before being put on the shelves, how long it sits on the shelves before purchase, and then how long it sits in your refrigerator before you eat it. For produce that is locally grown, the turnaround time can be short, reaching the grocery store within a day or two after harvest. And the popularity of the food can determine how long it sits on the shelf before purchase. Foods that are eaten more frequently are purchased more often, so they may only sit in the store for a day or two. And then, here’s the big question. How long does produce sit in your refrigerator before you eat it? As I’m writing this, I just finished eating a salad with spinach that I bought a week ago. I meant to eat it sooner…just…kinda… never got around to it. Guess what? The longer it takes before the food is eaten, the more nutrients that are lost in the process. So, my salad was not as nutritious as it would have been if I had eaten it a week ago when I bought the ingredients!
While frozen foods are often seen as inferior to fresh, this is not always the case. Frozen fruits and vegetables are often frozen very soon after they are harvested. Though there is some nutrient loss during the blanching process (cooking briefly in boiling water), it is minimal, and freezing the food preserves the remaining nutrients until you are ready to eat it. Freezing the food also helps prevent damage and bacterial growth, both of which can decrease the nutrient content. So, depending on the length of time before you eat your “fresh” fruit or vegetable, frozen foods may offer a higher nutrient content.
Canned foods have gotten the worst rep, from the added preservatives to the sodium content to the mushy texture of the food inside. But how do the nutrients stack up against fresh produce? Just like frozen foods, canned foods are also canned soon after they are harvested. There are various ways of preserving canned goods, and some of these methods may cause some nutrient loss. Also, preservatives and seasonings can increase the sodium content of the food, providing too much sodium per serving. Some canned goods are offered in a low-sodium or no-salt added variety, and these should preferably be chosen. If those are not available, you can also drain the canned solids and rinse them off to remove much of the sodium from the food.
I was curious how much the nutrients can differ in fresh vs. frozen vs. canned, so I did a comparison for spinach. Notice, for some nutrients, the frozen and canned spinach are higher than fresh!
Spinach
Serving Size: 1 cup
|
Nutrient
|
Fresh, boiled, drained, no salt added
|
Frozen, boiled, drained, no salt added
|
Canned, regular, boiled, drained
|
|
Calories
|
41
|
65
|
49
|
|
Protein (g)
|
5.35
|
7.6
|
6
|
|
Fat (g)
|
0.5
|
1.6
|
1
|
|
Carbohydrates (g)
|
6.75
|
9
|
7.2
|
|
Fiber (g)
|
4.3
|
7
|
5
|
|
Sodium (mg)
|
126
|
184
|
689
|
|
Calcium (g)
|
245
|
291
|
272
|
|
Iron (g)
|
6.4
|
3.7
|
4.9
|
|
Magnesium (mg)
|
157
|
156
|
163
|
|
Potassium (mg)
|
839
|
574
|
740
|
|
Zinc (mg)
|
1.37
|
0.9
|
0.98
|
|
Vitamin C (mg)
|
17.6
|
4.2
|
30.6
|
|
Thiamin (mg)
|
0.17
|
0.1
|
0
|
|
Riboflavin (mg)
|
0.42
|
0.3
|
0.29
|
|
Niacin (mg)
|
0.88
|
0.8
|
0.83
|
|
Folate (mcg)
|
263
|
230
|
210
|
|
Vitamin A (mcg)
|
943
|
1146
|
1049
|
|
Vitamin E (mg)
|
3.74
|
6.7
|
4.15
|
|
Vitamin D (IU)
|
0
|
0
|
0
|
|
Vitamin K (mcg)
|
888.5
|
1027.3
|
987.8
|
*Data from USDA Nutrient Database at http://ndb.nal.usda.gov/ndb/search
Here are a few tips to make sure you are getting the most nutrients from your fruits and vegetables, regardless of whether they are fresh, frozen, or canned!
*Buy local
Remember, the more time that passes between when a food is fully ripe and when it is eaten, the lower the nutritional quality. If you purchase food grown locally, the food is able to get to the store more quickly because the transportation time is less. Check your grocery store to see which items are grown locally. Also check for farmers markets around your city. A farmers market is typically a market where farmers sell directly to customers, enabling you to purchase fresher, healthier, and most times, cheaper produce.
*Visit the grocery store often
Though many of us like to shop for days, and sometimes, weeks at a time, it may be beneficial to purchase fresh fruits and vegetables more often. Purchasing fresh fruits and vegetables right before you use them will help ensure they have a higher nutrient content than if you allow them to sit in your refrigerator for a week before consuming them. Try visiting the grocery store a couple times a week, if possible. If not, you may want to also stock up on frozen or canned goods so that you always have the freshest produce available.
*Choose healthy cooking methods
How you cook your food plays a HUGE role in its final nutritional quality. Do you like to boil your vegetables forever until they are nice and soft? As the vegetable softens, vitamins and minerals seep out of the vegetable and into the water you are cooking it in. The longer the vegetable cooks, the more vitamins and minerals that escape the food. You may prefer the soft texture of an overcooked vegetable, but you are minimizing the nutritional value of the food.
- Steam: Challenge yourself to steam vegetables in a small amount of water… just enough to create steam to cook the vegetable in. Then, cook the vegetable until it is crisp. If you are used to overcooking your veggies, eating the vegetable crunchy may take some getting used to, but once you do, there is no turning back! You will enjoy the crunchiness of the vegetable and will immediately be able to taste when a vegetable is overcooked. Check out this article from the Food Network on how to steam your veggies: http://www.foodnetwork.com/healthy-eating/healthy-how-to-steaming-veggies/index.html
- Roast: Roasting is also another way to cook tasty, nutritious vegetables. Here is a great article from Better Homes and Gardens on how to roast and the best types of vegetables to roast: http://www.bhg.com/recipes/how-to/cooking-basics/how-to-roast-vegetables/
- Sauté: To sauté a veggie is when you cook bite-sized pieces in a small amount of oil in a heated pan. This is another way to quickly cook your food and retain the nutrients.
As you can see, there are many factors to consider when choosing the healthiest sources of fruits and vegetables. The key points to remember are to purchase the freshest produce available, to eat fresh produce within a couple days after purchasing, and to choose a cooking method that preserves as much of the nutrients as possible. Bon appétit!
A picture of my homemade Southwest salad, made with a mix of fresh and canned veggies!
Resources:
“Is Local More Nutritious?” It Depends. Available at:http://chge.med.harvard.edu/sites/default/files/resources/local_nutrition.pdf
Post-harvest losses (vegetables). Available at: http://en.wikipedia.org/wiki/Post-harvest_losses_(vegetables)
Prevention of post-harvest food losses fruits, vegetables and root crops a training manual. Available at:http://www.fao.org/docrep/t0073e/T0073E01.htm#Foreword
Food Network website. Healthy How-To: Steaming Veggies. Available at: http://www.foodnetwork.com/healthy-eating/healthy-how-to-steaming-veggies/index.html
Better Homes and Gardens website. How to Roast Vegetables. Available at: http://www.bhg.com/recipes/how-to/cooking-basics/how-to-roast-vegetables/
Well done, thanks for the insights. I just knew frequenting Costco was good for me!