summary:
. a doctor who wrote a healthy lifestyle book
says that sautéing is the best method for retaining nutrients;
but, sautéing involves browning the food,
and exposing fat to high heat.
. browning via heat is a Maillard_reaction:
Acrylamide, a possible human carcinogen
can be generated as a by-product of that.
. browning is related to AGEs
(Advanced_glycation_end-products)
however, I suprised to find
that compared to the diet I had supported,
browning vegetables is a relatively minor source
at least if very little oil is used;
because, foods high in even good fat
tend to contain high levels of AGEs
regardless of cooking method or being raw
-- relevant to a ketogenic (high-fat) diet.
J Am Diet Assoc. 2013:
Advanced Glycation End Products in Foods
and a Practical Guide to Their Reduction in the Diet.
"Modern diets are largely heat-processed
and as a result contain high levels of
advanced glycation end products (AGEs).
". grilling, broiling, roasting, searing, and frying
propagate and accelerate new AGE formation
[Crit Rev Food Sci Nutr. 1989,
J Am Diet Assoc. 2004]."
"In all food categories, exposure to
higher temperatures and lower moisture levels
coincided with higher dAGE levels
for equal weight of food
as compared to foods prepared at
lower temperatures or with more moisture.
Thus, frying, broiling, grilling, and roasting
yielded more dAGEs compared to
boiling, poaching, stewing, and steaming.
Microwaving 6 minutes or less
did not raise dAGE content to the same extent
as other dry heat cooking methods."
"... in animal studies, a reduction of
dietary AGE by 50% of usual intake
is associated with reduced levels of oxidative stress,
less deterioration of insulin sensitivity
and kidney function with age,
and longer life span [Am J Pathol. 2008:
Oral glycotoxins determine the effects of calorie restriction
on oxidant stress, age-related diseases, and lifespan.
"advanced glycation end products (AGEs) in the diet
correlates with serum AGE levels, oxidant stress,
organ dysfunction, and lifespan."]
. oils and nuts are AGE-rich, even in their
uncooked and minimally-processed forms;
for example, measuring just one of many AGEs,
we find in 100g:
grilled veg(broc,carrot,celery): 226 kU AGE;
-- a browning process yet not very toxic;
whereas,
raw cashew (steamed briefly) contains 6730;
-- compare to roasted: 9807;
so, most of the toxin is from the natural fat
not the roasting. compare also,
100 mL (3.38fl oz) extra virgin olive oil: 10,040.
protein is a moderate source too:
100g chicken boiled 1 hour: 1,123
-- or half that if using acidic solutions
such as lemon juice or vinegar marinades.
salmon canned: 917
salmon raw: 528
no mention of raw yolk but
100g yolk cooked 10 min is: 1193
