Should I Cook My Vegetables or Eat Them Raw?
(Are Raw or Cooked Vegetables More Nutritious?)
What is the Best Way to Prepare Vegetables?
I’m somewhat surprised this issue isn’t discussed more often.
(I've been paranoid about it for years!)
Anyone who leads a healthy lifestyle (or tries to), reads nutrition labels, considers buying specific organic foods and actually knows what certain vitamins and minerals do- has probably wondered if they are really getting and absorbing all the nutrients on the nutrition label.
That's one of the legitimate arguments to buying organic vegetables. The "regular" foods are grown in over-harvested, nutritionally exhausted soil and cannot possibly have as many absorbable nutrients as vegetables grown in more healthful conditions.
Growing up, my Dad (he retired the day I was born, at age 50) prepared most of my meals.
Any vegetables that I ate were generally boiled at 450 degrees for 40 minutes.
(sometimes 90 minutes when he forget that he was cooking me vegetables)
When I told my college nutrition professor (a registered Dietician, as well) at the University of Florida about this, he said that the vegetables probably lost 90% of their nutrients and I should have been eating them raw.
I proposed the same question to my doctor (who had a decent background in nutrition) but he said that there was no issue with that whatsoever, it was still way better than eating them raw and my professor “knew nothing,” about what he was talking about. My doctor was pretty adamant in his response.
Both of them, EXPERTS- with completely opposite opinions.
So What’s The Deal???
How we cook the foods we eat is a really important factor in the quality of our diet. It helps us to digest the foods we eat, that our digestive system is not built to break down – i.e. raw meat, fiber and cellulose. There are plenty of raw food “guru’s” out there that will swear [to their God] that cooking your food, particularly vegetables, destroys the vitamins and minerals found within them.
This, then, “supposedly” leads to deficiencies and a host of other vague, non-specific symptoms such as fatigue, poor sleep, weight gain, headaches – the usual run-of-the-mill symptom/ailment claims made by many uneducated and misinformed self-proclaimed guru’s.
But is there really any science behind these claims?
Does the concept of “raw eating” really offer pronounced health benefits over cooking our food?
And what exactly is the best way to prepare our vegetables?
Keep reading to find out the answers.
Can Vegetables Even Lose Their Nutrients?
Yes, but let’s proceed with caution.
Vegetables contain large amounts of vitamins, minerals and enzymes, all of which are critical for a healthy diet.
Naturally, the level of vitamins, minerals and enzymes are lost in a few scenarios-
First- the nutrients found in vegetables are naturally lost as the vegetable/s begin to degrade and become rotten. This is why it is important to store your vegetables in a cool refrigerated environment in order to preserve their nutritional value and shelf life.
Second- oxygen (oxidation) can also speed up the nutrient degradation process. Cut or half eaten vegetables should be stored in an air-tight container in a cool refrigerated environment to reduce the amount of nutrients lost.
Finally, the part we are most interested in- some of the nutrients found in vegetables can be lost through the process of cooking or heating them. However I can’t stress that it is only some of the nutrients, NOT all of them. In fact, some vitamins, minerals, antioxidants, phytochemicals and enzymes are actually increased by cooking or heating them.
So the answer is-
Yes, some vegetables can lose some of their nutrients if cooked or overcooked.
Cooking Can Increase the Nutrients in Some Vegetables
As just mentioned- cooking (and slightly overcooking) vegetables can increase the amount and the absorption of nutrients in certain vegetables.
A 2002 study published in the “Journal of Agriculture and Food Chemistry”, scientists found that heating tomatoes increased the amount of Lycopene by 35%. Lycopene is an antioxidant commonly found in tomatoes and other red pigment vegetables such as bell peppers. The researchers explained that- during the cooking process, the heat helped to break down the tomatoes' cell walls and this, in turn, helped the body to absorb higher amounts of the nutrients found within the cell walls, particularly the Lycopene.
Eating the tomatoes in a raw state, however, did not offer the same benefits as the body’s digestive system was unable to completely break down the cell walls in order to obtain the extra Lycopene.
Another study published in the 2008 “British Journal of Nutrition” showed that those who followed a strictly raw diet had lower levels of plasma Lycopene than those who cooked their vegetables. Lycopene has been shown to play an important role in reducing the risk of chronic diseases such as coronary heart disease and cancer.
The benefits of heating or cooking aren’t limited to tomatoes.
The beta-carotene content of cooked zucchini and broccoli is also better than that of its raw counterpart. A study published in the 2002 “Journal of Agricultural and Food Chemistry” illustrated that cooking these vegetables enhanced the levels (and absorption) of beta-carotene and as well as select other nutrients.
However, to be fair-
NOT all cooked vegetables offer improved nutrient profiles when compared to their natural, uncooked, raw state.
Some Vegetables Are Better For Us Raw
On the flipside - cooking or heating of some vegetables does appear to lead to a loss of nutrients.
A study published in the 2007 “Journal of Food Science” showed that steaming and boiling of green vegetables (specifically broccoli) caused a 22-34% loss of vitamin C, while microwaved and pressure-cooked vegetables only lost approximately 10% of their vitamin C content.
The researchers believed that the water content the vegetables are exposed to may be a common factor in the amount of nutrients lost in the cooking process.
Frying or stir-frying vegetables also appears to be a method that promotes a higher loses of nutrients, as the direct heat causes some of the nutrients to be destroyed.
Piecing It All Together...
Turns out, my Florida physician and University of Florida professor of Nutrition were both right.
(or wrong, depending on how you look at it)
Cooking vegetables has benefits, as does eating them raw.
The only thing that you can be certain of is that flash frying or SIGNIFICANTLY overcooking vegetables to point where they lose their shape will decrease their nutritional content.
Even still, unless you totally overdo it- they will still retain the majority of their nutrients.
Arguably the quality, rather than the method of cooking/heating, of your vegetables is the most significant factor in their before-you-swallow-it nutritional profile.
In our opinion, this subject is not worth stressing about.
Even if you psychotically carried around a little green notebook that perfectly broke down the nutritional content of every vegetable heated to every specific degree, it would still be nearly impossible to unanimously decide what is the best state to eat your vegetables in – raw or cooked [at what temperature].
Comparing the pros and cons of raw versus cooked vegetables is imperfect, extremely complicated and time consuming.
For every nutrient that might be enhanced through the cooking or heating process, there is likely to be
an equally important nutrient that is decreased or destroyed as a result.
The quality of the vegetable is usually a more significant factor.
Most people cook their vegetables because they enjoy how they taste.
I don’t know about you, but I’d hate to have to eat a sweet potato raw.
In fact, I probably wouldn’t eat them at all if I had to eat them raw.
Taste alone is the biggest factor that makes people eat vegetables or avoid them.
If cooking vegetables or eating them raw means you will eat more of them, then eat them raw. You’ll end up eating more nutrients that way.
If you do cook your vegetables, here's a nice little chart that tells you how long to do so for-
We also made a more comprehensive, printable chart-
So in answer to the question –
Which is the best way to prepare your vegetables?
WHICHEVER WAY you like to eat them.