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(Looking at the Science on Raw vs. Cooked Foods--continued, Part 1J)

Conclusion: assessing the risks of cooking
by-products in context

A concise summary of the main effects of by-products formed as a result of cooking is shown in the table below, with a wrap-up and concluding commentary about these effects following.

Cooking By-Product

Main Effects

Main Source

Dietary MRPs
(Maillard reaction products)
  • Antinutritional.
  • Anticarcinogenic.
  • Risks for vascular system and kidney in diabetics.
All cooked or stored foods, especially those high in protein and carbohydrate.
Endogenous AGEs
(advanced glycation endproducts)
  • Aging.
  • Risks for vascular system and kidney in diabetics.
NOT in food. (Generated in the body by non-food pathway.)
(heterocyclic amines)
Mutagenic, carcinogenic if dosage is high enough. Meat and fish cooked at high temperatures.
(polycyclic aromatic hydrocarbons)
Mutagenic, carcinogenic if dosage is high enough. Meat and fish cooked at high temperatures.

Highest temperatures represent the primary risk. It appears from the research about Maillard molecules, heterocyclic amines, and PAHs that the most dangerous compounds are formed at the highest temperatures, and that the longer the processing time, the more reaction products appear. The main effect of Maillard molecules themselves is that they slightly reduce lysine availability (other effects are probably minor), but on the other hand, they have anticarcinogenic properties.

One of the arguments found in the book Manger Vrai, by G.C. Burger (founder of "Instinctive Nutrition"), is that light cooking may be more dangerous than severe cooking, because slightly denatured molecules can pass the body's first-line digestive barriers more easily (since they are similar to naturally occurring molecules), and then accumulate in the body because they are unusable. While it's possible the reasoning as to passage through digestive barriers might be true as far as heat-denatured proteins are concerned, no evidence has been found that denatured proteins might be toxic. (Heat-denaturing merely means that the amino acids in a compact protein sequence have been unfolded by heat and become entangled with other unfolded protein sequences, not that the components of the proteins themselves have been changed.) On the other hand, Burger's reasoning doesn't apply at all for the Maillard reaction, since:

Cooking probably represents a small risk in overall context, particularly with diets that are predominantly raw already. It seems that, among all the causes of cancer, and all the factors (including various dietary factors besides cooking) at different stages of its development, carcinogens from cooked food would be likely to play only a modest role, even in the context of the standard American diet ("SAD"). Moreover, with more gentle cooking practices (avoidance of frying or grilling, preference for rare meat and/or steamed vegetables), very little toxicity results from cooking: it should be clear from our analysis that, for example, steamed spinach is not "poison," contrary to what some people claim. Besides, as remarked earlier, since natural foods do contain a certain toxin load of their own, it is very doubtful whether eating 99-100% raw makes much difference compared to, say, 90% raw or even 75% raw, contrary to what many raw-foodists believe.


(PART 2: Does Cooked Food Contain Less Nutrition?)

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GO TO PART 1 - Is Cooked Food "Toxic"?

GO TO PART 2 - Does Cooked Food Contain Less Nutrition?

GO TO PART 3 - Discussion: 100% Raw vs. Predominantly Raw

Back to Research-Based Appraisals of Alternative Diet Lore

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