Fresh Vs. Frozen Foods: The Surprising Truth

When it comes to food and nutrition, the amount of bad information that has become so ingrained into people’s minds that it has become “fact”, never ceases to amaze me 

Hearing things like “don’t eat carbs after 6pm; eating eggs raises your cholesterol; an alkaline diet cures all diseases”… and other such bull$#!t really makes my blood boil because I know that people that don’t know any better (the general population) take it for truth. I consider it an obligation to my clients and readers to debunk these “nutritional lies”, one at a time.

One thing that I constantly hear amongst certain professionals in the “alternative health” field (which I spent years working in myself) is that frozen fruits and vegetables are virtually nutritionally dead compared to their fresh counterparts. That the process involved in preparing vegetables to be frozen and the actual act of freezing itself destroyed the vitamins and minerals (and even the natural life force… I know, cringe!!!) of the vegetables in question leaving them little more than colorful shells of their former selves (kind of like how you feel after leg-day in the gym).

However, with actual evidence at hand, I (and after reading this article, you too) can confidently shrug off this nutritional lie.

The simple fact of the matter is that freezing produce is a fantastic way of preserving their vitamin, mineral and phytonutrient (such as non-nutrient antioxidants) content and because of the amount of time that “fresh” vegetables spend in getting from the field to your mouth, in many cases, frozen may even be better from a nutritional standpoint.

 In an ideal world, we’d all have our own little farms producing all the foods that we need to live long, healthy lives. Every day, we’d stroll out into the garden, bathed in warming sunlight and freshly pick some vegetables at the peak of their ripeness and eat them mere minutes later. In this ideal world there would probably also be friendly, talking animals and people roar in laughter at the thought of Donald Trump running for president… The ideal world doesn’t exist.

We live in the real world meaning we buy our “fresh” produce from the supermarket and store it in the fridge until we have time to use it. For a bit of perspective on how “fresh” that produce is consider the following:

• between harvest and arrival at a distribution center, produce can spend up to 5 days in transit
• if produce is coming from another part of the world, that time can increase to a few weeks
• in the supermarket, fruit and veg may spend up to 3 days on display before you buy it
• at home you may store some produce up to 7 days or more before finally eating it {1} 

So the “fresh” produce you buy may be a couple of weeks old by the time you actually eat. Considering degradation of nutrients (particularly vitamins) in fruit and vegetables starts as soon as the food is harvested, you are probably consuming a nutritionally inferior product compared to something freshly picked from the field.

Here’s a quick overview of the freezing process to help you understand where nutrient loss might occur {2}:

• Produce is harvested and transported to a processing facility as rapidly as possibly (the fresher the produce the better the final frozen product)
• Produce is washed
• Produce may be peeled and chopped if necessary
• Produce may be blanched: it passes through a hot water or steam bath for a few minutes, which inactivates enzymes that can cause further spoiling of the food
• Produce is rapidly frozen, packed and stored for distribution

It’s important to remember that in the freezing process, the most easily “lost” nutrients in vegetables and fruits are water-soluble vitamins (vitamin C and the vitamin B group) along with water-soluble phenolics (members of the phytonutrient group mentioned earlier) {3,4}. In general, fat soluble vitamins (vitamins A,D,E & K), minerals and fiber are retained much better in frozen foods {5,6}.

The point where most nutrient loses occur is probably during washing and blanching where water soluble vitamins, phenolics and some minerals can leach into the water used for processing (especially if the food is chopped with a large cut surface area). Steam blanching helps to minimize these losses (this is also why steaming is healthier than boiling veg as you don’t lose nutrients in the water that is thrown away after cooking. The heat used in blanching probably causes some destruction of heat-sensitive nutrients like vitamin C and some B vitamins. However, the blanching process is far milder than most “cooking” processes in the home.

Once frozen, however, there is very little change in levels of nutrients in the foods over extended periods of time (which is the real advantage of frozen food).

The majority of studies show that foods stored frozen for a period of months has similar levels of nutrients compared to the same foods stored in a “fresh” state in the fridge for as little as 3 or as many as 10 days. In some cases, frozen foods even scored higher in vitamin and mineral levels than their “fresh” counterparts {4,6}.

This obviously varies according to nutrient: vitamin C, widely considered one of the most unstable vitamins, is lost significantly in frozen products {5,7}, so many frozen foods (and foods stored for long periods of time in general) are not particularly good sources of vitamin C. β-carotene (used by the body to make vitamin A) can also be lost over time by oxidation but the heat treatments used before freezing may make it more bioavailable {8} (a common trait with carotene nutrients and one that contradicts the belief the “raw” is always better).

Another factor that is important is the physical form of the vegetable/fruit when it’s frozen. Leafy vegetables like spinach, because of their fragile form that easily wilts with heat, tend to lose more nutrients due to blanching than broccoli, which is usually kept mostly intact when freezing {4,6}. Vegetables that are chopped also tend to lose more nutrients than whole vegetables as chopping damages cells exposing them to water during blanching and allowing for oxidation during storage. Whole or roughly chopped veg may be better.

With all this in mind here’s a list of some fruit and vegetables that I recommend buying in frozen form. It is by no means an exclusive list but helps give an idea as to whey these are good choices;

• Berries (strawberries, blueberries, raspberries etc.) (don’t get blanched and aren’t chopped)
• Mushrooms (don’t get blanched and aren’t chopped)
• Broccoli (isn’t chopped)
• Baby carrots (better than chopped/sliced carrots)
• Peas (aren’t chopped)
• Green beans (minimally chopped)

That said, most frozen vegetables are excellent choices especially when you take economy and convenience into account (I love being able to just through pre-sliced vegetables into a stew or soup as I’m making it at home… less chopping and less clean-up.

We all know that we should be eating plenty of vegetables to live long, healthy lives {9}. Increased vegetable consumption is associated with reduced weight and reduced risk of a whole host of diseases from diabetes to cardiovascular disease to cancer {10-12}. Long story short, your mother was right and you need to eat your fruit and veggies.

However, while eating lots of vegetables is important, so is consistency in doing it. Healthy eating needs to be practiced every day and that’s why I’m a fan of anything that can make healthy eating more convenient or efficient. This is where frozen vegetables really shine as they have the following advantages over fresh:

• Frozen fruit/veg can be stored for longer without losing nutritional value
• Some nutrients are higher in frozen fruit/veg than in excessively stored fresh produce
• You can always have healthy veg/fruit at hand even if you haven’t been shopping in a while
• You save time, as most frozen food is ready to cook (less chopping/cleaning time)
• You save money (in some cases) as there is less waste from skins/inedible parts

Ever had a salad made with frozen lettuce and tomatoes? It doesn't work. I’m not saying that you should switch to frozen food completely but it does make nutritional, economic and practical sense to have frozen food in the home.

The most important thing that I want you to understand after reading this article is that frozen food is not the nutritionally dead garbage that some people would have you believe. Instead, it can form a very convenient part of a healthy and balanced diet. And if you’re like the majority of people that store their fruit and vegetables for a long time before eating them (as I write this I can see some apples in my fruit bowl that have been there for almost 2 weeks) then switching to more frozen produce may actually give you a nutritional boost.

Eat well, folks

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Bibliography

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