I have always thought, and told others, that fresh fruit and veggies are FAR more healthy than frozen and cooked ones and far better than pill-form multi-vitamins. Reason being that the vitamins and chemicals in them are still natural and “living” and undisturbed/undenatured by heat or cold.
If this is true, that they are healtheir, why is this? Exactly, technically, why? Something to do with the atoms’ spin or the organic nature of the vitamins and phytochemicals?
There is no chemical difference between the vitamin C in pill form or still in the orange; they are the exact same molecule.
However, with the orange you get water (from the juice), trace nutrients, citric acid, some fiber, and sugars which can be converted into energy. Also, the breakdown of foodstuffs is an important part of a healthy metabolism.
This is a common idea, but untrue. Of course, if you overcook veggies, you cook out the nutrients. They’re best just steamed lightly. But frozen veggies are actually often more nutritious than fresh, and here’s why: let’s take a fresh head of broccolli. It gets picked, and may sit in the field for two days before someone loads it into the truck. Another two days to get to the market. Two days in the storage room at the market. Two to five days in the bin in your produce section. Losing nutrients the whole time. But, with canned and frozen veggies, the broccolli is grown and picked right where it’s processed. So it’s frozen within 24 hours of picking, not nearly the nutrient loss as for the fresh! (I don’t mean to imply that fresh veggies aren’t good. If they’re still fresh enough to look good so you buy them, they’ve got plenty of nutrients left).
As for the pills, xcheopis is right that vitamin c is vitamin c, no matter what the source. But fresh produce (and frozen/canned) has phytonutrients and such that science don’t even understand completely yet. Plus they have fiber, which is very good for you. So yes, the real thing is much better than a pill.
Of course, there was a recent study (and I cannot currently find the cite) that indicated taking vitamin E tablets to reduce the risk of heart disease was not effective, while eating vitamin E laden foods was.
My WAG for this is that while eating vitamin E laden foods, the person is also consuming the previously mentioned nutrients, in addition to filling up on healthy stuff, and not junk.
How does the broccolli sitting in the field lose nutrients? Do you mean that when they are tossed around, parts of the veggie break off or parts of the veggie are exposed to the air and are damaged somehow?
Norinew, could you answer my question assuming the veggie gets processed in the same amount of time?
I’m sorry, but just saying that it’s the same molecule is being too short-sighted. I guess a more detailed question could be about pills and how the vitamins are extracted and dealt with. What if those pills’ lack of water and fiber makes the vitamins less useable by the body, or less digestable or absorbable? A vitamin C molecule is probably much better (more absorbable) attached to fiber and containing a water molecule, i would presume??? Vitamins with cellulose in them aren’t as natural as real fiber in an orange, i’m sure. (I’m no scientist)
Is that same vitamin C molecule the same after being heated to 160 degrees?
As for the phytochemicals i and QTM mentioned, that’s reason enough to eat the real thing and quit messing around with pills, but that’s another thread i guess. Long live raw spinach and carrots!
Another aspect of “healthier” is that uncooked fruits and veggies have a lower glycemic load–that is, cooked vegetables are more readily digested, and thus increase blood sugar more quickly. Uncooked vegetables contribute to more even blood sugar across the day.
However, some phytochemicals such as lycopene (part of the carotenoid family) are released in much greater quantities when the vegetables are cooked. This is why various prostate cancer organizations suggest eating cooked tomatos – they release far more lycopene, which may help inhibit the formation of prostate cancer. Without cooking, the phytochemicals stay bonded within the cell walls and are not available for absorption. This is probably true for beta-carotene and other beneficial molecules.
This is true. That’s why juicing is so good, it seperates the good stuff from the fiber so that you can absorb it. THat brings me to another question:
I have heard that when you juice carrots and spinach and celery, you must drink it quickly, within 30 minutes or so, in order to get the full benefits. Is this true and why or why not? THe answer to this question ties in pretty well with the subject at hand.
What I read is that there are three forms of the vitamin E chemical and you need all three for the antioxidant effect that reduces heart attacks. Vitamin pills have only one form of the vitamin, while foods have all three.
Think of it this way: It’s safe to assume you were intended to eat foods the way they naturally occur, otherwise humans would not have been able to survive a time when they could not eat everything in pill form. It’s pure logic (in non-pill form).
Actually, juicing does not achieve the same benefits as cooking. It’s really the heat that releases lycopene. Here’s a quotation from an abstract of a study done at Cornell, where the “antioxidant activity” of raw tomatoes was compared to cooked tomatoes. The numbers listed are the equivalent of vitamin C activity. I’ve edited it slightly to make it more readable. Cooking for 30 minutes increased antioxidant activity by more than 50%:
Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity. Authors: Dewanto V, Wu X, Adom KK, Liu RH.
The antioxidant activity of raw tomatoes was 4.13 of vitamin C equiv/g of tomato. With heat treatment at 88 degrees C for 2, 15, and 30 min, the total antioxidant activity significantly increased to 5.29, 5.53, and 6.70 of vitamin C equiv/g of tomato, respectively (p < 0.01). There were no significant changes in either total phenolics or total flavonoids. These findings indicate thermal processing enhanced the nutritional value of tomatoes by increasing the bioaccessible lycopene content and total antioxidant activity and are against the notion that processed fruits and vegetables [necessarily] have lower nutritional value than fresh produce.
A little more on what I said above. Vitamin E actually has about 8 forms, but I recall reading that 3 of them team up for the antioxidant effect. Something like one absorbing an excess electron which then passes it on to a second form and then to the third form. Sort of a chemical game of hot potato. What the third form does with it I don’t remember. I believe I read this in Science News, but a search of their web site failed to turn up the article.
As for whether vitamin pills have all the forms of Vitamin E, that depends on how they produced the vitamin. Some have all forms, some only the most active, some may have other combinations.
You know what? I don’t think modern science is ready for this question, what do you all think? I mean, we don’t even understand phytochemicals! Forget it. We don’t know, so i’ll continue to do what’s natural and tell others to do the same. At least i know cooking doesn’t totally nullify the nutrition and in some cases helps it.
Yes. Cooking carrots in oil releases the most alpha and beta carotene.
Estimation of carotenoid accessibility from carrots determined by an in vitro digestion method.
Eur J Clin Nutr 2002 May;56(5):425-30
"RESULTS: Three percent of the total beta-carotene content was released from raw carrots in pieces. When homogenized (pulped) 21% was released. Cooking the pulp increased the accessibility to 27%. Addition of cooking oil to the cooked pulp further increased the released amount to 39%. The trends for alpha-carotene were similar to those for beta-carotene. "
This was mentioned by Alton Brown on Good Eats last week. According to him that while with some fruits and vegetibles cooking does break down some of the nuitriants at the same time it makes the food easier to digest meaning that you typically absorb more in the end than if they were uncooked. And enough people here have already mentioned that heat helps certain things in food be better for you…
Well, this is news to me. I see that i was probably right about cooking killing off some nutrition, but it seems that cooking brings back the nutrition two-fold. Never would have guessed that! Thanks Dopers. I won’t be spreading anymore more ignorance anymore on this subject!