It turns out frozen vegetables are just as nutritious as fresh ones

I've been eating a lot of frozen vegetables lately because it's winter, they're cheap, and they don't go bad immediately like fresh ones do.

But I started wondering if they were as nutritious as fresh veggies. Was I missing out on nutrients in favor of convenience?

Companies advertise that frozen vegetables are picked and packed at the peak of freshness.

So what does the science say?

It turns out we have nothing to worry about.

Two large reviews of the published scientific literature on the subject found that frozen vegetables (and canned for that matter) are just as nutritious as fresh ones.

The researchers compared the different amounts of vitamins, minerals, fiber, and other nutrients. While there is some variability depending on how the frozen vegetables were processed — high heat can degrade some nutrients, for example — the authors concluded that "nutrients are generally similar in comparable fresh and processed products."

But you should watch out for added sodium or sugars in frozen or canned vegetables, the American Heart Association warns. The daily recommended sodium limit for adults is 2,300 milligrams, and most Americans are over that guideline.

Check the label to see if the package lists salt or sugar as an ingredient. It should just say the type of vegetable it is, nothing more.

I looked through the nutrition facts on canned, frozen, and fresh corn to compare the three, and the canned corn listed "corn, water, and salt," as ingredients.

This gave the canned corn 144 milligrams (mg) of sodium in a single 90 gram serving, compared to 0 mg for the same amount of frozen corn and 10 mg for the fresh corn. Eating it from the can means that half a cup of corn would account for over 6% of your daily sodium limit.

Obviously these sodium numbers can change depending on the brand, so it's important to check the label. There's usually a "low-sodium" or "no sodium" option that you can buy instead.

But you shouldn't worry about frozen vegetables being less nutritious.

And if they're always on hand, they can be a great way to get your daily serving of two to four cups of veggies.

Convenience, in this case, can pay off.