Did Eating Meat Help Our Brains Evolve?

[mgb_phys]

EMFs don't cause any other damage to the molecular structure?

Not at microwave energies - these are much lower energy than any of the molecular bonds and so don't cause any chemical changes other than heat. The same isn't true of UV that can do chemical damage without heating.

I agree but we eat food for the nutrition, if the way we are cooking could be damaging the nutritional value of the food, I would consider that harmful even if it is safer.

For meat, heating is probably a benefit - it breaks down muscle fibre and makes it more digestible. It denutures some proteins but you don't use protein directly you break it down into amino acids. For vegatables heating is more a loss, a lot of vitamins are destroyed by heating, especially cooking in water.

 

[russ_watters]

Oh, I thought the door on my normal oven was to keep the heat from escaping so I can cook at the temperature of my choosing.

Good point, it works both ways - as does the door on the microwave!

I agree but we eat food for the nutrition, if the way we are cooking could be damaging the nutritional value of the food, I would consider that harmful even if it is safer.

There is an awful lot of info out there about the effects of cooking on nutritional value of foods. Yes, various forms of cooking can have an effect:

Q: What's the best way to cook vegetables to keep the most nutrition intact?

A: As with all colors of vegetables, the more they're cooked the more vitamins and minerals are lost. The vegetables tend to break down when exposed to heat. "The longer and hotter you cook them, the more nutrients you are likely to lose.

The ideal way to eat vegetables and preserve the biggest amount of nutrients is to eat them raw, but if you are cooking your vegetables, try steaming them either in a steamer or in the microwave. Stir frying also can be a good way to preserve the nutrients. Always use as little water as possible, and avoid boiling vegetables, as the vitamins, minerals and phytochemicals will escape into the water rather than remaining in the vegetables. Also try to keep the vegetables in larger pieces when cooking. The more their surface is exposed to air and/or water, the more likely you will lose those important vitamins and minerals.

http://www.recipestoday.com/expertqa/cooking/what-s-the-best-way-to-cook-vegetables-to-keep-the-5791

 

[Proton Soup]

the biggest sin of microwave cooking is that the food comes out tasting like crap. i believe much of this is because the microwaves overheat the food. with water, you only get up to a temp of 212 (or a little higher i think can happen under certain situations), but with oil/grease, the boiling point is much higher. this may actually be dangerous, as it changes the chemical composition of the food compared to what it would be cooked by traditional methods.

Effect of different cooking methods on some lipid and protein components of hamburgers
Purchase the full-text article



References and further reading may be available for this article. To view references and further reading you must purchase this article.

M. T. Rodriguez-Estrada, G. Penazzi, M. F. Caboni, G. Bertacco and G. LerckerCorresponding Author Contact Information, E-mail The Corresponding Author

Istituto di Industrie Agrarie, via S. Giacomo 7, 40126, Bologna, Italy

Received 11 April 1996;
revised 21 August 1996;
accepted 18 October 1996. ;
Available online 8 December 1997.

Abstract

The effects of different cooking methods on the lipid and protein fractions of hamburger were evaluated. The lipid component was subjected to the following analyses: peroxide value; p-anisidine; total and free fatty acids; cholesterol and its oxidation products (quantified as 7-ketocholesterol). Lysinoalanine (LAL), free amino acids and D-amino acids (D-AA) were also determined in the protein fraction. All results were compared with a raw control. No significant differences were found among the cooking treatments with respect to D-AA and LAL. The degree of proteolysis, lipolysis and lipid oxidation varied depending on the treatment conditions. Regarding cholesterol oxidation, the combination of roasting and microwave heating caused more oxidation than the other treatments. The raw meat, however, showed an advanced degree of oxidation (25.2 ppm of total 7-ketocholesterol/120 g ground meat).

microwaving also destroys B12 and who knows what else

J Agric Food Chem. 1998 Jan 19;46(1):206-210.
Effects of Microwave Heating on the Loss of Vitamin B(12) in Foods.

Watanabe F, Abe K, Fujita T, Goto M, Hiemori M, Nakano Y.

Department of Food and Nutrition, Kochi Women's University, Kochi 780, Japan, and Department of Applied Biological Chemistry, Osaka Prefecture University, Sakai 593, Japan.

To clarify the effects of microwave heating on the loss of vitamin B(12) in foods, raw beef, pork, and milk were treated by microwave heating and then their vitamin B(12) contents were determined according to a chemiluminescent vitamin B(12) assay with hog intrinsic factor. Appreciable loss ( approximately 30-40%) of vitamin B(12) occurred in the foods during microwave heating due to the degradation of vitamin B(12) molecule by microwave heating. When hydroxo vitamin B(12), which predominates in foods, was treated by microwave heating and then analyzed by silica gel 60 thin layer chromatography, two vitamin B(12) degradation products were found. One of the compounds with a R(f)() of 0.16 was purified and partially characterized. The vitamin B(12) degradation product did not show any biological activity in the growth of a vitamin B(12) requiring microorganism, Euglena gracilis Z, and was not bound to hog intrinsic factor, a mammalian vitamin B(12) binding protein. Intravenous administration of the compound (1 µg/day) for 7 days to rats showed that the compound neither has toxicity nor acts as a vitamin B(12) antagonist in mammals. These results indicate that the conversion of vitamin B(12) to the inactive vitamin B(12) degradation products occurs in foods during microwave heating.

PMID: 10554220 [PubMed - as supplied by publisher]

 

[vanesch]

But my question is about the FOOD which is cooked with microwave oven.

Do you know what happens to them?

I once heard the silly comment that it is safer for microwaved food to leave a few minutes open in the air before eating it, so that the microwaves that got into it have time to escape :rofl:

 

[jreelawg]

I once heard the silly comment that it is safer for microwaved food to leave a few minutes open in the air before eating it, so that the microwaves that got into it have time to escape :rofl:

I've heard this one before. The claim was that certain molecules can absorb the frequencies of the radiation and re-emit it. This is true of certain gas molecules in the air absorbing and re-emitting harmful UV radiation, but I haven't verified if molecules can do this with microwave radiation or not, or if it did, how long after bombardment it could pull this off. I think that this probably happens practically instantly.
What's the word for this anyways?

 

[vanesch]

I've heard this one before. The claim was that certain molecules can absorb the frequencies of the radiation and re-emit it. This is true of certain gas molecules in the air absorbing and re-emitting harmful UV radiation, but I haven't verified if molecules can do this with microwave radiation or not, or if it did, how long after bombardment it could pull this off. I think that this probably happens practically instantly.
What's the word for this anyways?

Fluorescence (fast) or phosphorescence (slow). Don't think it is possible with microwaves, but I'm not sure.

In any case, it wouldn't do anything to you, as it would be very low power. Heated food (no matter how) will radiate away much more high-frequency infrared radiation than it will radiate away low-frequency microwaves.

In fact, it happens more with traditionally heated food, which radiates away part of the infrared radiation it received during classical heating. This is also called "cooling". If you wait for a few hours, most of the extra infrared radiation is radiated away (and hence the food is cold again).

 

[alxm]

Fluorescence (fast) or phosphorescence (slow). Don't think it is possible with microwaves, but I'm not sure.

Fluorescence, yes, but with a much much lower probability, because the excited state will easily undergo non-radiative relaxation (= get hotter. Which is the point.) Phosphorescence is not possible.

To whatever extent there is fluorescence, you're talking about picoseconds. Not only will it have radiated off before you have a chance to open the microwave, it'll have radiated off before you even heard the microwave's beep.


Anyway it's all been studied and no, microwave ovens aren't dangerous. Microwaved food isn't dangerous, and nor does it contain less nutrition or anything else. (If anything, it contains more. Since conventional heating heats from the outside-in, it requires a longer time to cook things and destroys more nutrients in the process.) The one plausible health-drawback is bacteria in food that's been unevenly cooked.

 

[mheslep]

...
You don't need to guess how much energy escapes microwaves -- it's easily measurable, and is certainly measured by the engineers who design it and qualify it.

Your microwave oven is not unsafe, even if you put your face near it. Relax.

- Warren

Though I'm not sure of the mechanism for enforcement, they are required to be tested to meet government standards on leakage:
http://www.hps.org/hpspublications/articles/microwaveoven.html

Certainly microwave ovens have EM radiation standards and are tested. However, as I recall some of the earlier ovens (decades ago) used inadequately specified door gaskets and developed leaks exceeding standards over time due to use, abuse, and heating cycles. The risk in such a case would be tissue heating and not ionization - particularly in the eye lens which is susceptible to heating, causing cataracts.

 

[Dale]

There are two big dangers with microwave ovens (assuming it is correctly functioning):

1) the food can be undercooked and still have some pathogen
2) you can burn yourself with the food after taking it out

Both are also dangers with regular ovens.

 

[Proton Soup]

Anyway it's all been studied and no, microwave ovens aren't dangerous. Microwaved food isn't dangerous, and nor does it contain less nutrition or anything else. (If anything, it contains more. Since conventional heating heats from the outside-in, it requires a longer time to cook things and destroys more nutrients in the process.) The one plausible health-drawback is bacteria in food that's been unevenly cooked.

well, I've provided some evidence that suggests otherwise.

 

[russ_watters]

well, I've provided some evidence that suggests otherwise.

While you are right in that alxm's post was overly positive toward microwaves, yours didn't really add much since there was very little in the way of substantive differences shown in what you posted/quoted. Heating, whether via microwaves or any other method, does have an affect on food's nutritional value. Does microwaving food decrease nutritional value more than other methods? I don't know, but your links/quotes don't make much of a case either way.

On the general point:

Nearly every food preparation process reduces the amount of nutrients in food. In particular, processes that expose foods to high levels of heat, light, and/or oxygen cause the greatest nutrient loss. Nutrients can also be "washed out" of foods by fluids that are introduced during a cooking process. For example, boiling a potato can cause much of the potato's B and C vitamins to migrate to the boiling water. You'll still benefit from those nutrients if you consume the liquid (i.e. if the potato and water are being turned into potato soup), but not if you throw away the liquid. Similar losses also occur when you broil, roast, or fry in oil, and then drain off the drippings.

The table below compares the typical maximum nutrient losses for common food processing methods.

http://www.nutritiondata.com/topics/processing

 

[Proton Soup]

While you are right in that alxm's post was overly positive toward microwaves, yours didn't really add much since there was very little in the way of substantive differences shown in what you posted/quoted. Heating, whether via microwaves or any other method, does have an affect on food's nutritional value. Does microwaving food decrease nutritional value more than other methods? I don't know, but your links/quotes don't make much of a case either way.

On the general point: http://www.nutritiondata.com/topics/processing

i don't think I'm disagreeing with that, only that microwaving has the worst effect.

also, what do you mean by substantive, statistically significant? anyhoo, i appreciate your nutritiondata link, but something more "substantive" that addresses the issue at hand (microwave cooking) would be nice.

 

[mheslep]

i don't think I'm disagreeing with that, only that microwaving has the worst effect...

Where is the comparison made? I only saw the evidence regarding uwaving in of itself reducing nutrition (as does convection heating).

 

[Proton Soup]

Where is the comparison made? I only saw the evidence regarding uwaving in of itself reducing nutrition (as does convection heating).

in the screenshot from google books that i posted, it gives a little more information than what is in the abstract regarding 7-ketocholesterol production. combined microwaving and roasting produced the most, followed by microwaving alone. ergo, microwaving is the worst when considering each individually.

 

[russ_watters]

i don't think I'm disagreeing with that, only that microwaving has the worst effect.

Yes, I know that's what you are claiming. What I am saying is that your post doesn't really help you much with that claim.

also, what do you mean by substantive, statistically significant?

Substantive means relevant and substantial. What you provided is just really really thin.

anyhoo, i appreciate your nutritiondata link, but something more "substantive" that addresses the issue at hand (microwave cooking) would be nice.

My link certainly had more overall relevance than yours because it is broader and it points directly to a particular flaw in your information! The B12 study talks only about one vitamin and only about microwaving. But if "cooking" (methods not specified) can reduce B12 by up to 50%, well then the study that says microwave cooking reduces it by 30-35% in a particular test is completely useless for addressing the claim that microwave cooking reduces nutrition more than other methods, isn't it? As mhselp said, it needs to compare microwaving to other methods to have any value at all.

Your first study is perhaps more useful, but it doesn't say how much difference it noted between the cooking methods and what is done to cholesterol is just one small piece of the puzzle. Obviously, meat is always cooked, but what is probably a bigger issue is nutrients lost in veggies and the differences in losses can be huge, not to mention the difference between cooking and eating them raw! And I don't know anyone who would cook a hamburger in a microwave anyway. If nothing else, cooking on a grill let's fat drain away from it.

My point here is that characterizing this as an issue specific to microwave ovens just isn't realistic and your links just aren't that useful or compelling.

 

[Proton Soup]

Yes, I know that's what you are claiming. What I am saying is that your post doesn't really help you much with that claim.
Substantive means relevant and substantial. What you provided is just really really thin. My link certainly had more overall relevance than yours because it is broader and it points directly to a particular flaw in your information! The B12 study talks only about one vitamin and only about microwaving. But if "cooking" (methods not specified) can reduce B12 by up to 50%, well then the study that says microwave cooking reduces it by 30-35% in a particular test is completely useless for addressing the claim that microwave cooking reduces nutrition more than other methods, isn't it? As mhselp said, it needs to compare microwaving to other methods to have any value at all.

Your first study is perhaps more useful, but it doesn't say how much difference it noted between the cooking methods and what is done to cholesterol is just one small piece of the puzzle. Obviously, meat is always cooked, but what is probably a bigger issue is nutrients lost in veggies and the differences in losses can be huge, not to mention the difference between cooking and eating them raw! And I don't know anyone who would cook a hamburger in a microwave anyway. If nothing else, cooking on a grill let's fat drain away from it.

My point here is that characterizing this as an issue specific to microwave ovens just isn't realistic and your links just aren't that useful or compelling.

you are right in that there is no point of comparison for b12 and that there lacks magnitude info on the other. i'll have to see if i can find more, but it's not an easy topic to dig up info on.

 

[russ_watters]

More: http://www.ehow.com/about_5415255_nutritional-food-cooked-microwave-oven.html

The FDA further states that microwave cooking does not reduce the nutritional value of foods compared with traditional cooking methods...

All foods change, no matter the method used in preparation. In fact, the FDA states that some foods might have greater retention of their nutrients when cooked in a microwave oven because of rapid heating. Traditional cooking methods require water, which absorb some of the nutrients and require longer cooking times. Taking great care to follow cooking times and instructions, as with traditional cooking, reduces the risk of draining food of its nutrients.

Cooking any food in any manner reduces its nutritional value in some way. The only way to retain foods nutritional integrity is to not cook it at all. And even then, if you remove any peelings or outer skin, such as peeling a potato, you are reducing its value of nutrition because the majority of nutrients are in the skin of many fruits and vegetables.

 

[Proton Soup]

apparently, it's not a huge difference. still, i avoid fatty meats that are microwaved. it does something to the meat that just makes it taste disgusting. i'll be trusting my body on this one.

http://apjcn.nhri.org.tw/server/APJCN/Volume11/vol11.1/Savage.pdf

 

[chroot]

apparently, it's not a huge difference. still, i avoid fatty meats that are microwaved. it does something to the meat that just makes it taste disgusting. i'll be trusting my body on this one.

No one said microwaved food tastes good. It's usually nasty... but not dangerous.

- Warren

 

[russ_watters]

No one said microwaved food tastes good. It's usually nasty... but not dangerous.

- Warren

And whether I heat my Hot Pockets in the microwave or in a toaster oven is a secondary issue to why I am eating disgusting sacks of fat in the first place!

 

[chroot]

Actually, on an unrelated note, microwave oven really only shines is when it is used in one way. It's very common for a cook to have several dishes (cooked with traditional cooking methods) that come together at slightly different times, yet need to be heated to the same temperature immediately before being served. The microwave is great for just adding a touch of heat to a finished dish while leaving the plates room temperature. Many, many restaurants nuke their finished plates for 15 seconds right before serving them.

- Warren

 

[Proton Soup]

No one said microwaved food tastes good. It's usually nasty... but not dangerous.

- Warren

maybe. I'm going to keep an open mind about it. even this ability to do accurate oxysterol testing is relatively new from what I've read.

and maybe I'm a nut, but i won't eat that prepackaged walmart meat, either. how meat that tastes like burnt hair and cheese can be good for you is a mystery to me. :uhh:

 

[chroot]

Well, strictly speaking, no meat is really considered 'good for you' at all, except maybe fish.

- Warren

 

[Proton Soup]

Well, strictly speaking, no meat is really considered 'good for you' at all, except maybe fish.

- Warren

eh, i don't know about that. i think most of the studies condemning meat haven't really considered lean red meat, which is incredibly nutritious.

but fish is certainly awesome. maybe awesome enough to think that humans might be natural piscivores...

 

[Pythagorean]

I watched an evolutionary documentary that claimed our brains got bigger and began to utilize strategy once we started eating meat because it provided the energy necessary for higher brain functions. I believe it was nova. A Baldwin was hosting it.

edit: it was "walking with caveme"