Fresh, Frozen or Canned: A Guide to Maximize Nutrition

You make choices every day—do you turn to the pantry, the fridge or your freezer for tonight's dinner? Which offers you the best nutritional punch?

Let's examine the three options, from what happens when it's picked to its arrival on shelves and, then, to your plate.

It's in the can

Canned produce has received a lot of bad press over the years. Granted, they're not the ultimate source of nutrients, but when fresh or frozen is not available, canned is a viable source of food.

The canning process involves three main steps:

• Processing, where the food is peeled, sliced and cooked.
• Sealing, when the food is sealed in cans.
• Heating, where cans are raised to a very high temperature to kill harmful bacteria and prevent spoilage.

The caveat here lies in the heating process. The heat is set so high that enzymes are killed off, too, which can be problematic as enzymes are required for proper digestion. Additionally, many nutrients are heat-sensitive, so they can be denatured in this process.

There's also the issue of bisphenol-A (BPA), an industrial chemical used in the canning process. Issues have arisen where BPA has leached into food and caused possible health effects on the brain and prostate gland of fetuses, infants and children. A few canning manufacturers offer a ceramic lining, considered much safer, eliminating leaching.

Tomato products containing oils are especially unstable at a molecular level, encouraging leaching. Next time you're pouring out canned tomatoes, take a look at the inside of the can. Notice a red tinge? That's the exchange of molecules: Tomatoes go into the composition of the can and vice versa. The same goes for plastic containers. We're all familiar with those orange-stained food storage containers. When it comes to oily or acidic produce, glass jars are your best bet—and easy to find in grocery stores these days.

"Canned, in most cases, is my last choice," said Ricki McKenna, a certified nutritionist, health coach, chef, speaker and author. "There's nothing like a fresh peach or even green beans that can compare to canned."

The deep freeze

Frozen produce is harvested at the peak of ripeness. It's sorted, washed, oftentimes blanched (to inactivate certain enzymes that degrade texture and color in the freezing process), and flash-frozen within a few short hours of picking, which helps lock in freshness and conserve nutrients. No preservatives or additives are added.

Unlike fresh produce, frozen fruits and veggies don't see a decrease in nutrients and antioxidant compounds, including polyphenols, anthocyanins, lutein and beta-carotene.

In addition to its higher nutritional value, frozen produce saves you time in the kitchen, as it's already prepped, so all you need to do is open the bag and add those veggies to your pan or pot to make a nutritious meal or add them to your blender and make a delicious smoothie.

Frozen foods can be kept in the freezer for many months and can save you money at the register, too, because frozen fruits and veggies are usually less expensive than fresh.

Another bonus is it's an environmental plus because it eliminates food waste. Frozen food companies often use "ugly" or "imperfect" produce that the farmer tosses from the fresh pile, and this produce, after freezing, won't go bad waiting for you to use it.

"Frozen would be my second choice since most commercial and especially organic fruits and vegetables are picked when they are ripe and then flash-frozen, so they have most of their taste and nutritional value," explained McKenna. "However, after a while, I believe they lose some of their taste. And frozen food requires a specific time to cook, whereas with fresh, you have the choice of how well done you'll cook something, and that's important for, say, green beans or Brussels sprouts."

Is fresh best?

In commercial or large-scale farming, fresh produce is rarely harvested at the peak of ripeness. Farmers harvest fruits and vegetables before they're fully developed in the hopes of giving them time to ripen during transportation and while sitting on store shelves. Unfortunately, harvesting fruits and vegetables before they're ripe doesn't allow time for the full spectrum of vitamins, minerals and antioxidants to develop.

Once fruits and vegetables are harvested, the packaging process begins. This includes getting rid of debris, washing, sorting by size, and gassing and waxing in an effort to delay decay and make the produce look more appealing to consumers. Next comes the packaging itself, where corrugated boxes and pallets are used to protect the produce while it makes its way to grocery stores.

Depending on the produce's origin, trucks, trains, airplanes or ships are involved in this next step. Most fruits and vegetables sold in the U.S. come from California and Canada, with some coming from Mexico. You might find a few items from faraway lands, but rarely. This journey can take several weeks or even months, and it's possible the produce can be exposed to light, heat and cold, all of which can further reduce nutrient levels.

The entire process—from harvesting to your dining table—may take so long that fruits and veggies have lost what little nutrients they have. However, there's a solution. If you're fortunate enough to live near a farmers market, you're more likely to find produce sold the day it's harvested, which could give you the biggest bang for your nutritional buck. If there isn't a farmers market near you, most major cities offer Community Supported Agriculture (CSA) you can subscribe to.

If you're fortunate enough to live near a farmers market, you're more likely to find produce sold the day it's harvested, which could give you the biggest bang for your nutritional buck.

"Fresh is best most of the time," McKenna said. "When the food is in season and at the peak of development and ripeness, the taste and nutritional value are usually far better than when produce is picked early for shipping and has to ripen on store shelves or in bins. Shopping at a farmers market is always best for fresh fruit and veggies."

As the seasons change around the world, so do the types of produce that flourish. In our modern world of supermarkets and transporting, importing and exporting, we have the luxury of fresh fruits and vegetables available all year round, but that seasonal peak can't be replicated.

The answer?

Eating seasonally is optimal. This means eating foods that are harvested at the same time of year that you're eating them. You'll notice it helps out your pocketbook, too, as in-season produce is more affordable.

LE Saba holds credentials as a registered holistic nutritionist, health coach and environmental health specialist. She has written for hospital systems and ghostwritten for practitioners and coaches for nearly 40 years. She has also compiled educational materials for health coaches and edited books on holistic nutrition and psychological wellness.