Sourced from: Infinite Health Blog, by Dr. Davis,
originally posted on the Wheat Belly Blog: 2014-02-21
don’t know your right from your left
(Replacement P.D. Image - original lost)
knowing your right from your left in nutrition can get you into trouble.
In biological systems, there is an issue
called “handedness,” or “chirality.” It
means that there are right-handed (“Dextrarotatory”)
and left-handed (“Levorotatory”) versions of compounds,
or “D” and “L” versions, or isomers, much
as we have right and left hands, mirror images of each other. But
a right-handed glove does not fit on your left hand and vice
versa. Likewise, enzymes only recognize one or the other isomer,
not both. Mammals are largely L-isomer creatures, due to
specificity of enzymes for L-versions of compounds.
Most foods — and I mean real
food, foods that are instinctively recognized as food by humans,
such as shellfish, organ meats, berries, nuts, and roots–have
proteins made of L-amino acid isomers, not D.
Things that don’t belong in the human
diet, such as grasses from the family Poaceae, have plenty of
D-isomer amino acids. Because enzymes are subject to the rules
of chirality, human digestive enzymes, such as trypsin and
chymotrypsin, that digest proteins receive a “stop”
signal when they encounter an indigestible D-isomer in a protein,
leaving that protein or peptide fragment undigested.
Add D-amino acids to the other
generally indigestible components of wheat and grains. Beyond
D-isomer amino acids, other indigestible components of the
seeds of grasses include:
- Gliadin–While some gliadin is degraded to small peptides
that act as opiates on the human brain, a substantial proportion
of gliadin remains undigested. The intact, undigested
form is the form that initiates the zonulin
mechanism that increases intestinal permeability, the first
step in generating the diseases of autoimmunity.
- Wheat germ agglutinin (WGA)–The complex, 4-part protein
present in wheat, rye, barley, and rice is completely indigestible.
WGA that enters the mouth comes out the back end–except for
the small quantity that penetrates intestinal barriers, causing
direct intestinal toxicity and entering the bloodstream to activate
antibodies, mimic insulin, and block leptin (the hormone of satiety).
- Trypsin inhibitors–Trypsin inhibitors
block–no surprise–trypsin, a protein required for
protein digestion. This further reduces the digestibility of
grain proteins, a fact that organizations, such as the World Health
Organization, grapples with when starving nations are fed grains
but then struggle with malnutrition despite the calories.
There is a digestible component of
wheat and the seeds of other grasses: the amylopectin A
carbohydrate, highly susceptible to digestion by the amylase enzyme
of saliva and stomach. This explains why two slices of whole wheat
bread raise blood sugar higher than six teaspoons of table sugar. If
you were starving, no real food in sight, and found yourself in a
field of wheat, you could indeed harvest the seed, pulverize it, and
eat it as porridge or ground into flour. It would serve as a source
of carbohydrates and a minor source of proteins and oils. But you
would soon suffer poor health and malnutrition, then die, as
Homo sapiens cannot survive on the mix of components
in the seeds of grasses.
If it often seems that there are SO many
problems with wheat and grains, well, that’s because they never
belonged in the human diet in the first place. Yes, we have committed
a 10,000-year long mistake that began in desperation when we ran low
on real foods, turning to the wild fields of grasses and harvesting
their seeds. The food of desperation is now the food celebrated by
all official agencies.