The Truth About Vegetables

21 02 2013

Broccoli_Fresh_vs_Frozen

I eat a lot of vegetables. On a good day, I’ll consume at least 1-2 servings of broccoli, avocado, cauliflower, onions, spinach, beets, and whatever else I might have been impulsive enough to buy at the grocery store. The more vegetables I eat, the better I feel; a crazy correlation, I know.

Why are vegetables so important you ask? To name a few of the benefits:

– They are rich in antioxidants (protection against free radicals and disease), vitamins, minerals, fibre (GI health), and phytonutrients that protect us against carcinogens and have anti-bacterial and anti-viral properties.

– They contain lots of water to help you stay hydrated.

– They are alkaline producing, which can help to preserve bone mass and muscle tissue.

– They are nutrient-dense and calorie-poor, meaning they make you feel full without detrimental calories, helping you control overall food intake and manage body weight.

The majority of the vegetables I consume are fresh. When I’m strapped for time and can’t make it to the grocery store, I’ll use frozen vegetables; but these really act as a backup. I’ve always believed that fresh produce would give me more nutrients than frozen vegetables, and additionally that eating raw vegetables would be more valuable than those that are cooked. I believed all this without ever once doing any research or consulting any experts on the subject. Now I have, and I’d like to share my findings!

Are raw vegetables more nutritious than frozen vegetables?

There is little-to-no evidence to support this claim. Most fresh vegetables (think: those your find in large commercial grocery stores) have spent multiple days in transit, and the longer fresh veggies are left from the moment they are picked, the more nutrients they lose; not to mention the preservative chemical sprays and UV lights at the grocery store. Frozen vegetables, on the other hand, are typically picked at their peak ripeness and snap frozen after blanching, which preserves the vitamins.

Many studies have shown that frozen vegetables are just as nutritious as fresh produce, and there are additional studies showing that frozen vegetables are actually more nutritious than out-of-season imported produce. Other studies have shown lower calcium content in frozen vegetables, but those same vegetables held a higher vitamin C value than their fresh counterparts.

Although frozen vegetables can be healthier than fresh produce, this will only be true if you avoid veggies packed with additional chemicals or processing formulas. Sodium is sometimes added for taste and any vegetables prepared in a sauce will contain high amounts of fat and preservatives. Vegetables that are properly frozen and kept frozen should not need any preservatives! You can also look at the nutritional information to find out the mineral and vitamin content and tell if there was any processing done to diminish the nutritional value (although you’ll first need to know the typical nutritional value of that given veggie).

Not sure if frozen children are as nutritious as fresh ones...

Not sure if frozen children are as nutritious as fresh ones…

Are raw vegetables more nutritious than cooked vegetables?

Again, there is very little proof that this is true, and in fact, some cooked vegetables have proven to be more nutritious than their raw counterparts.

Depending on the cooking method and the particular food, cooking can either enhance or destroy the nutrient availability in food.  High temperature cooking (like boiling) is likely to reduce the availability of most water-soluble vitamins (ie, Vitamin C).  However, many vegetables (carrots, spinach, mushrooms, asparagus, cabbage, peppers, zucchini, etc.) have been found to supply more antioxidants, such as carotenoids and ferulic acid, when they are steamed or boiled, rather than when they are raw. Where boiling and steaming better preserve antioxidants, frying eliminates them through oxidation.

In the end, nutrient loss from cooking generally amounts to no more than 10-25% of most vitamins and virtually nothing in minerals. Cooking vegetables helps to maintain the integrity of some vitamins and minerals, but can also cause vegetables to lose some nutrients as well. Some cooking methods are preferable to others, but there is no definite rule here.

My recommendations?

– If possible, grow your own vegetables; this will ensure the highest nutritional value.

– If you cannot grow your own vegetables, find a local market or roadside stand where you can purchase fresh vegetables from your neighbours’ gardens. Furthermore, try to find out what they use to grow their vegetables and be sure to ask where their produce came from; some roadside vendors may supplement their own stock with vegetables shipped in from larger commercial farms.

– If neither of these options are possible, you are almost surely better off buying frozen vegetables, as they will have avoided any transit time, preservative sprays, etc. However, if you can find locally grown produce at the grocery store, this is also a great option. Here in Canada, it will be easier to eat fresh, local produce in the summer months, but the winter months are where frozen vegetables may need to become more prevalent in your diet.

– The least nutritious vegetables you can buy are those that have been imported and are the furthest from the date they were picked. Again, frozen vegetables will almost surely be more nutritious in this case.

– In regards to raw vs. cooked vegetables, I think it would be prudent to eat a mix of both.

– For raw vegetables, be sure to thoroughly wash the fresh produce prior to consumption.

– For cooking, try to avoid frying and boiling vegetables, but instead stick to steaming, baking or grilling (under medium heat).

** Bonus tip: Fat helps your body absorb the vitamins and minerals in your vegetables. This doesn’t give you permission to load up on the ranch dressing, but adding nuts, avocado or healthy oils to your salad can be very beneficial.

Moral of the story

Vegetables are good for you, no matter how you get them into your body. If you can get freshly picked vegetables, these are surely your best option; if not, frozen veggies are the next best thing (and won’t be far off nutritionally). In the end, there isn’t a huge difference between raw and frozen vegetables, nor between raw and cooked veggies, so mix it up and do what’s best for your lifestyle! As always, I will encourage you all to buy local and buy Canadian, but above all else: EAT YOUR VEGGIES!

For more information on diet and nutrition, you know how to find me!

DW