Skip to Content

Fresh, Frozen, or Canned Vegetables and Fruits—Which Are More Nutritious?

Close-up of a man holding a bag of frozen vegetable while standing in front of a frozen food section
Photo: Shutterstock.com/evgeniykleymenov

Various circumstances can dictate our food choices at the grocery store. While The Paleo Diet® encourages eating whole fruits and vegetables over other forms that have been minimally processed (such as canned or frozen versions of the same), fresh produce is not always viable for everyone. Someone may live in a food desert and only have access to a certain food in its frozen state, or canned food may be prioritized if preparing for a natural disaster like a hurricane.

When faced with the choice of buying unprocessed or minimally processed versions of produce, you may be left wondering if one form is more nutritious over another. The short answer is this: Whether you buy fresh, frozen, or canned vegetables and fruits, all are nutritious and essential to a healthy diet. Since it is recommended to eat up to 3 cups of vegetables and 2 cups of fruits daily, and only 10% to 20% actually do so,1 eating any form is better than none at all.

Though there is a push to move away from processed foods, don’t be misled. We support the consumption of a variety of fresh, frozen, and canned vegetables and fruit as close to their natural state as possible to get all the necessary nutrients for good health. The USDA estimates that by purchasing a variety of each in all forms, the average cost is $3 per day per person to eat five servings daily.1

Scientists have long tried to measure and compare the effects of storage and processing on the nutrients of fruits and vegetables. It’s not an easy task since the variety, growing conditions and location, maturity at harvest, and production methods affect the nutrient density of each vegetable or fruit. Researchers have primarily focused on the antioxidant activity of plant foods, as well as the nutritional comparisons of vitamins A, B, C, E; phenolic compounds, carotenoids, minerals; and fiber to make this feasible.2, 3

Some of you may already be thinking: What about seasons, storage, time, processing, and cooking methods that can degrade nutrients? In most cases, the nutritional density of the vegetable and fruit is still intact, and the differences are minimal except for water-soluble vitamin C, which is prone to degradation.2 Below, we review the science, explain the nutritional nuances, and offer tips on how to store fruits and vegetables to keep them fresh.

Living and Breathing Vegetables and Fruits

Whether from a farmers market or a supermarket, the allure of fresh vegetables and fruit is intoxicating. There is a reason our senses are immediately alerted to the aroma, texture, and colors of spiky artichokes, blushing apples, bright orange carrots and apricots, cheery red tomatoes, and forest-green globes of broccoli. Plants use advertising coloration when pigments are the most vibrant and nutritional density is at its highest to attract animals to eat them.4 It is how plants are biologically programmed to reseed and survive.5

What happens after harvest? Once a vegetable or fruit is cut off from its nutrient source, it continues to use calories to keep cells alive for as long as possible. They ripen and breathe (called respiration), using sugars and oxygen to stimulate cell growth and exhale carbon dioxide.6 Time, light, and heat speed up respiration, which leads to oxidization, nutrient loss, discoloration, and tissue breakdown.7 Packers and processors refrigerate, freeze, or can fresh vegetables and fruits soon after picking to slow or stop this process.

But Fresh Produce Is Better … Right?

We’ve already warned there is no single answer to this plant-based quandary, so let’s start with a utopian vision. Suppose a locally grown vegetable or fruit is picked at peak ripeness, immediately chilled (40°F), and eaten raw or lightly cooked within 24 hours. There are no guarantees, but technically, it is likely to be more nutritious than grocery-bought produce.7, 8 Add “organically grown” to this perfect scenario, and studies show notably higher levels of vitamin C, magnesium, and iron due to soil quality.9

If we can make one case for fresh vegetables, it is for broccoli, cauliflower, Brussels sprouts, and cabbage because they contain more sulforaphane than frozen. This compound, which stimulates detoxifying enzymes, is necessary for brain and eye health and reduces cancer risk. It is activated when the vegetables are chopped 30 minutes before eating raw, lightly steaming, or microwaving. Add a little mustard seed powder or wasabi to activate the enzymes if you prepare these vegetables from frozen.10

Now that you’ve enjoyed a few moments of perfection, let’s return to reality. Since most of our produce is bought at grocery stores—not plucked from a backyard garden—transportation time, storage conditions, and seasonality factor into the nutritional density of produce. These are the most significant barriers to retaining nutrient density.

“The journey from farm to supermarket for ambient temperature produce can take days or weeks. Once in the store, it can take several days longer,” says Kantha Shelke, Ph.D., a senior lecturer of food safety regulations at Johns Hopkins University.

On average, produce sourced within 100 miles of a store arrives at the store in one day. Produce grown more than 100 miles away takes three to five days to reach the store. However, some of this produce sits for weeks or months in cold storage.

Then consider imports.11 About 20% of vegetables and 50% of fruits sold in the United States come from outside the country, primarily Mexico, Canada, Indonesia, Colombia, and Peru.12 Now add your home refrigerator as the last leg of a vegetable or fruit’s life cycle, and there could be more nutrient reduction as it sits in the crisper drawer or on the counter.

Advances in commercialized storage for fresh produce mean less loss. Controlled Atmosphere Storage controls for oxygen, temperature, humidity, light, and gases like ethylene, allowing leafy greens to be stored for a few weeks and apples stashed away for up to a year before heading to the store. Without this technology, it would be difficult for grocers to provide fresh produce in the store all year.

The Facts on Frozen and Canned Vegetables

Given that the United States’ fresh produce supply chain is complex and long-haul transportation is necessary, especially in winter, freezing and canning are essential to overcome variables contributing to nutrient losses.

“Freezing is like a pause button,” says Dr. Shelke. “Modern freezing helps maximize the nutritional value of fresh produce.” Dr. Shelke explains that when fruits or vegetables are frozen, the process happens at the peak of ripeness, flavor, color, and nutritive value, especially for vitamin C, which can decline by 10-75% within a week after harvest.

Gaps in nutrients exist between fresh and frozen, but they are minimal. For instance, after a year of storage, frozen broccoli loses 10% of vitamin C, carrots lose none, and spinach loses 30%, compared to fresh, which declines by 75% after one week.2

Canned tomatoes, carrots, and pumpkins benefit from canning, with close to the same or increased levels of beta-carotene as fresh varieties because of heat processing.3 Canned tomatoes also have significantly more lycopene and vitamin E than raw varieties. The biggest negative for canned vegetables is added sodium and sugared syrups for fruit, though increasingly no-salt and water-packed versions are available.

Variety Is the Answer

All of the above is the only definitive answer to whether fresh, frozen, or canned vegetables and fruits are the best choice. How you care, store, and prepare vegetables at home can also make a difference in their nutritional quality.

  1. Buy only what you need. Do not prewash; store in a perforated bag (separate fruits and vegetables) in crisper drawers and eat within a week.
  2. Keep your refrigerator clean so that rotting produce doesn’t contaminate fresh.
  3. Refresh raw vegetables (radishes, celery, carrots) in ice water to hydrate and bring them back to freshness.
  4. Blanch and freeze excess fresh vegetables that you can’t eat in time. Fruit can be frozen without blanching. Label with the date (find more advice on how to properly freeze meat and produce here).
  5. Store onions, garlic, and sweet potatoes in a cool, dry place (ideally less than 70°F).
  6. Write the purchase date on frozen vegetable bags and eat the oldest first.
  7. Overcooking vegetables can reduce their nutrient content, so it’s recommended to steam or microwave vegetables for only a few minutes.

References

  1. USDA Economic Research Service, Satisfying Fruit and Vegetable Recommendations Possible for Under $3 a Day, Data Analysis Shows. https://www.ers.usda.gov/amber-waves/2024/september/satisfying-fruit-and-vegetable-recommendations-possible-for-under-3-a-day-data-analysis-shows/
  2. Barrett, D., et al. Nutritional comparison of fresh, frozen, and canned fruits and vegetables. Part 1. Vitamins C and B and phenolic compounds. J Sci Food Agric. Published 2007; 87;930-944. https://www.ahealthylife.nl/wp-content/uploads/2017/04/nutritional-comparison.pdf
  3. Barrett, D. et al. Nutritional comparison of fresh, frozen, canned fruits and vegetables II. Vitamin A, carotenoids, vitamin E, minerals and fiber. J Sci Food Agric. Published 2007; 0022-5142. https://ucanr.edu/sites/kingscounty/files/19188.pdf
  4. Brown, F.. et al. The adaptive value of biological coloration, Brittanica. https://www.britannica.com/science/coloration-biology/Repulsion
  5. Fox, D. L., & Burtt, E. H. (1999, July 26). Coloration | Definition, Biology, Examples, Types, & Facts. Encyclopedia Britannica. https://www.britannica.com/science/coloration-biology/Repulsion
  6. Prevention of post-harvest food losses fruits, vegetables and root crops a training manual – Pre-harvest factors in produce marketing-Perishability and produce losses-cont. (n.d.). Www.fao.org. https://www.fao.org/4/t0073e/t0073e02.htm
  7. Burden, J et al. Food and Agriculture Organization of the United Nations, Prevention of post-harvest food losses fruits, vegetables and root crops a training manual. Rome, 1989. https://www.fao.org/4/t0073e/T0073E00.htm#Contents
  8. Eastham, J. et al. Food losses, food waste, and beyond in food supply chains: Retaining optimum nutrient density. Food Frontiers. Published 2023; 4, 971–979. https://iadns.onlinelibrary.wiley.com/doi/epdf/10.1002/fft2.271
  9. Rahman A, et al. A Comprehensive Analysis of Organic Food: Evaluating Nutritional Value and Impact on Human Health. Foods. Published 2024;13(2):208. https://pubmed.ncbi.nlm.nih.gov/38254509/
  10. Men X, Han X, Oh G, et al. Plant sources, extraction techniques, analytical methods, bioactivity, and bioavailability of sulforaphane: a review. Food Sci Biotechnol. 2023;33(3):539-556. Published 2023 Oct 16. https://pubmed.ncbi.nlm.nih.gov/38274178/
  11. Leopold Center for Sustainable Agriculture. Food, Fuel, and Freeways: An Iowa perspective on how far food travels, fuel usage, and greenhouse gas emissions. Iowa State University. Published 2001. https://dr.lib.iastate.edu/entities/publication/51ef6421-3062-487f-af1a-29125328f7a5
  12. DSpace Angular Universal. (n.d.). Dr.lib.iastate.edu. https://dr.lib.iastate.edu/entities/publication/51ef6421-3062-487f-af1a-29125328f7a5

Kimberly Lord Stewart

Kimberly Lord Stewart is an author, journalist, and culinary expert. Her work highlights the importance of incorporating whole foods into daily diets and emphasizes the connection between food and overall well-being.

More About The Author
Kimberly Lord Stewart

Grocery Shopping

back to top