2011-01-17

what's cooking, doc?

1.17: news.health/stroke belt is frying poly'fats:
HSI - Jenny Thompson hsiresearch@healthiernews.com
HSI e-Alert - Southern fried Jan 17, 2011 at 5:07 AM

. within the states between the stroke belt
the risk of stroke seems higher for southeastern states
between Arkansas and the Carolinas;
this was curious because they eat plenty of fish
known for reducing strokes;
but an Emory University analysis of 21,000 usa diets
found that their fish is mostly fried,
at high heat, in oil rich in polyunsaturates,
or trans fats .
. another study showed fried fish is
increasing risk of heart attack and earlier death .

Problem #1: AGE's from high-heated poly'fats;
Mount Sinai School of Medicine 2009
compared normal food with an "AGE-less" diet
where foods were slow-cooked with plenty of moisture,
such as steaming or poaching.
. inflammatory markers (such as C-reactive protein)
were reduced while vascular function improved.

Problem #2: Trans fatty acids:
. people still use partially hydrogenated oils
or other sources of trans fatty acids;
even small daily amounts raise cardiovascular risks .

Problem #3: acrylamide from hot battered meat:
. most dietary acrylamide is formed by the
Maillard reaction:
when aspargine and reducing sugars
are heated above 100C° (212F).
brown-frying is temp > 170 °C (338 °F);
golden-frying reduces acrylamide formation:
145 to 170 °C (293 to 338 °F)
. typical sources of acrylamide are
coffee (54% of intake),
fried potatoes (12% of intake),
and toast (9% of intake).

food-browning can happen at low temperatures:
. fruit is dried at around 70C°(158F);
dark dried whole pears and prunes
contain surprising amounts of acrylamide .

. acrylamide (acrylic amide) is a potent neurotoxin,
and can also cause nausea, sweating,
urinary incontinence, myalgia[muscle pain],
speech disorders, numbness, paresthesia[tingling],
and weakened legs and hands.

. the body can break down acrylamide for fuel
via the citric acid cycle or
gluconeogenesis [liver-produced glucose];
but, along the way
this process can result in high levels of
the excitotoxic neurotransmitter aspartate .

. this is done with L-asparaginase
which removes an ammonium to form
the excitotoxic neurotransmitter aspartate;
A transaminase then converts the aspartate
to oxaloacetate .

. acrylamide is produced by any browning reaction
between a very common protein
(asparagine = aspartate + ammonia)
and a reducing sugar (glucose or fructose)
or a reactive carbonyl (aldehydes, ketones, carboxylic acid and esters).
. nearly any whole food with sugars
will also contain asparagine
unless L-asparaginase is added to break it down
into excitotoxic aspartate.

. the modern diet is rich in reducing sugars:
most popular sweeteners include them,
and should not be used in cooking .
# Honey is 38.2% Fructose, 31.3% Glucose;
# inverted sugar syrup is 50% glucose 50% fructose .

. table sugar (sucrose = glucose + fructose)
doesn't form acrylamide until there is
sufficient processing to break sucrose's binding
into separate molecules of glucose and fructose .
. in the usa, subsidized HFCS has replaced sucrose .

. High-fructose corn syrup (HFCS)
starts out as corn starch (glucose chains)
enzymatically degraded to glucose,
and converted to varying fractions of fructose .
HFCS 42 (for foods) is 42% fructose and 53% glucose.
HFCS 55 (for soft drinks) is 55% fructose, 42% glucose;
-- usually HFCS 42 + HFCS-90, 90% fructose, 10% glucose .

L-asparaginase can be used in cooking
to reduce levels acrylamide;
but, 10% of dietary acrylamide is not caused by asparagine;
so, breaking that down with L-asparaginase wouldn't always;
conversely,
avoid baking powder (ammonium hydrogencarbonate, NH4HCO3, E 503)
as it promotes much more acrylamide formation
than Baking soda (sodium hydrogencarbonate, NaHCO3, E501).

glycidamide formation:
links to cancer:
. acrylamide is metabolised in the liver
into the reactive epoxide, glycidamide .
. this epoxide forms DNA adducts,
ie, causing mutagenicity by adding things to DNA .

. glycidamide can also be directly formed in food
from high-temperature reactions between
acrylamide and poly'fats
but, most of the diet's glycidamide load
is from metabolizing acrylamide .

Advanced Glycation End-products (AGEs):
Foods with significant browning, caramelization,
cooking done at temperatures above 120°C (248°F),
the use cooking oils high in polyunsaturates
as opposed to monounsaturates (olive oil, almond oil, ...)
will result in Advanced Glycation Endproducts (AGEs).

Food manufacturers for the last 50 years
have added many AGEs to foods,
as flavor enhancers and colorants .
. foods with very high AGEs include:
donuts, cake, barbecued meats,
and dark colored soda pop.
. AGEs are also made naturally by the body
when excessive sugar is consumed
or when insulin resistance has developed .

Glycation:
Glycation is unintended chemistry between
saccaride derivatives (glucose, alpha-oxoaldehydes, ...)
and biochemistry (protein, phospholipids, guanyl nucleotides);
-- Glycation is also called non-enzymatic glycosylation;
ie, the intended chemistry is called glycosylation
and that depends on control by enzymes .

3-Deoxyglucosone (3DG)
3DG rapidly reacts with protein amino groups
to form AGEs such as imidazolone, pyrraline,
N6-(carboxymethyl)lysine and pentosidine.

. 3DG as well as AGEs play a role in the
modification and cross-linking of long-lived proteins
such as crystallin and collagen,
contributing to inflammation and aging diseases,
and the vascular complications of diabetes:
atherosclerosis, hypertension, Alzheimer’s disease,
and retinal circulation issues leading to blindness .