We all know we should eat more fruits and vegetables, specifically 5-9 servings every day, but only 1 in 10 Americans reach the goal. One of the easiest ways to increase that number is to choose frozen or canned produce, but navigating the health benefits can be tricky. Is fresh produce the healthiest? Should you bother with produce that has been processed at all?
The answer, like so many nutrition topics, isn’t that clear.
Let’s break it down into fresh, frozen and canned fruits and vegetables.
Fruits are straightforward, as the only processing they undergo for freezing is minimal transport, potential peeling, chopping, and washing. Once frozen, their nutrients are largely stable and can be enjoyed anytime. The main changes are to taste and texture. While freshly picked fruit tastes delicious, it can lose nutrients after spending days or weeks on the counter or in the fridge, so it’s good to have an idea of when you might eat them.
Fruit like peaches, pears and apples are often peeled before canning or pureeing, which causes loss of fiber and other beneficial compounds like polyphenols. The other consideration for canned fruits like applesauce and fruit cups is added sugar. Look for fruit packed in water or its own juice.
Vegetables are a little more complicated. Fresh seems like the obvious winner, but studies on cooking methods show that’s not necessarily the case, as cooking can make nutrients easier for our bodies to access. Even fiber, a pretty stable nutrient, can be more beneficial to after cooking.
One study compared broccoli, carrots and green beans grown and harvested at the same time and then refrigerated, frozen or canned. Their nutrient content was measured after certain time points and after being warmed up in the microwave. Vitamin C is often used as an indicator for other nutrients, as it is sensitive to heat, light, and oxygen, and was measured in this paper.
After the green beans were in the fridge for a couple of weeks, they had lost more than 90% of their vitamin C content, but the vitamin C in broccoli did pretty well. Carrots actually showed an increase in vitamin C during the first couple of weeks, and then only lost a little after being in the fridge.
As with commercially frozen vegetables, the ones in this study were blanched, or submerged in boiling water, before being frozen. This resulted in an initial loss of some nutrients, particularly vitamin C, but the nutrients were stable once frozen. The carrots were the only vegetables that were canned in this study; the canning process resulted in decreased vitamin C and beta carotene, then the nutrients were stable during storage.
The main consideration for processing produce is that freezing and canning both involve some type of cooking. We know that cooking produce at high temperature with water can cause some vitamins and minerals to leave the food and migrate into the water. There are some work arounds for this, especially with greens, like using the liquid for what Vivian Howard calls the Southern broth.
But even for the same food, different cooking methods altered different nutrients in different ways. Not only that, but produce is still living and breathing after it is harvested, so pinning down exact nutrition content over time is challenging. One review that attempted to provide consumers with an overview of the best ways to prepare foods didn’t have clear cut answers, but did conclude that steaming had an edge over other cooking methods for nutrition retention.
Cooking tomatoes, for example, makes it easier for our bodies to absorb the lycopene and boiling spinach makes the iron more bioavailable. It turns out that canned tomato products and Popeye’s canned spinach may not be such bad ideas! On the flip side, tomatoes and spinach are both good sources of vitamin C, and we know how heat can affect that.
It would be ideal to have a chart that shows how to buy every fruit and vegetable and the best way to cook them, but it is more complicated than that. Not only does it differ by food, but it differs by nutrient of interest and how well our bodies can use it.
And keep in mind that produce is more than what we see on the nutrition facts panel. There are so many other health benefits and promising compounds in fruits and vegetables, so you’re not going to go wrong enjoying more of them. One of the first studies to investigate the health benefits of an intact food, like an apple, rather than an isolated compound, like vitamin C, showed some of those benefits.
The bottom line?
Enjoy a variety of fruits and veggies, and don’t stress if there are some you only like raw or roasted. The best produce is the one you will eat, so try these tips to actually make that happen:
- Try something new: Getting a produce box or visiting a Farmers’ Market can be a fun way to try new fruits and vegetables.
- Sneak them in: Add vegetables to foods you already eat like soups, sauces, casseroles, and smoothies.
- Eat a rainbow: A bright and fun plate looks great, provides a variety of nutrients, and can help you eat more fruits and veggies.
- Keep trying: Sweet fruit is easy to love, but the taste of some veggies can make eating them a challenge. It may take over a dozen tries for your taste buds to adjust, so stay positive and keep tasting.
- Enjoy a dip: Try raw or lightly cooked veggies dipped in hummus, peanut butter, tzatziki, or guacamole, or ranch dressing made with yogurt.
- Buy it all: Fresh, frozen, and canned fruits and veggies are all great options. When choosing canned, look for fruit packed in water or its own juice and lower sodium veggies.
- Mix it up: Maybe you’re tired of steamed broccoli or hate mushy Brussels sprouts, so try cooking them in a new way. Who knows – another cooking method may also help your body absorb more nutrients!