So, you got the memo that soy is very
bad for the hormonal system. If you think that is the extent of the
damage the lowly soybean can wreak on your health, you may be
surprised to learn that soybeans are also notoriously hard to
digest with GMO soybeans – widely used in processed foods – the
absolute worst.
The culprit is the protease inhibitors
found in all soybeans whether organic or GMO. As the name suggests,
protease inhibitors suppress some of the key enzymes that help us
digest protein.
The best
known and most important of the protease inhibitors is trypsin. GMO
soybeans including edamame have more of them than organic or
conventional beans, and to make matters worse, those protease
inhibitors are stubbornly resistant to deactivation by cooking or
other processing methods.
Soybeans are not the only foods that
contain protease inhibitors. All beans contain them, as do grains,
nuts, seeds, vegetables of the nightshade family, egg whites, and
other foods. However, the protease inhibitors in those foods rarely
contribute to health problems because few of those foods are eaten
excessively and cooking deactivates most of them.
In contrast, there are more protease
inhibitors in soybeans than in any other commonly eaten food. While
protease inhibitors are not a problem for people who enjoy the
occasional soy dish, the quantities add up quickly when people
consume soy daily in the mistaken belief that it is a “healthy”
meat and dairy substitute.
For decades, USDA and other researchers
put their efforts into finding safe and inexpensive ways to
deactivate the protease inhibitors found in soy. Boiling, roasting
and modern processing methods help, but cannot destroy all of these
troublesome components. The only way to come close is through the
old-fashioned fermentation methods used to make miso, tempeh and
natto. Modern industrial processing techniques involving heat,
pressure and chemical treatments have been reported to kill off as
much as 80 to 90 percent, but that’s a promise, not a guarantee.
The numbers of live protease inhibitors
remaining in soy products varies from batch to batch, and
investigators have found unexpectedly high levels of protease
inhibitors present in some soy foods, and startlingly high levels in
some soy formulas.
Protease inhibitors are an especially
bad problem in GMO soybeans. With more than ninety percent of
commercial soybean crops now genetically modified — up from around
fifty percent in 2007 — there are very real health risks. Monsanto,
of course, claims these beans are substantially equivalent to the
conventional soybean, hence safe.
In fact, tests have shown significantly
higher concentrations of protease inhibitors in the toasted GMO
soybean compared to conventional soybeans. Furthermore, those found
in the GMO strain proved stubbornly resistant to deactivation by the
heat treatment known as “toasting.”
When the results first came in,
Monsanto took the bad news to mean that the GM beans had not been
properly cooked and asked for retreatment of the sample. Further
heating, however, widened the difference even more. The logical
conclusion would be that a substantial difference exists between the
GMO and conventional soybeans, and that the GMO soybean is more
likely to cause digestive distress and growth problems in humans and
animals.
Monsanto, however, concluded that the
second toasting was still not enough and toasted twice more until
they got the result they wanted, namely that ALL proteins were
denatured and inactivated. At this point, most of the soybean’s
protein value was also destroyed, but it gave Monsanto the “proof”
it needed to conclude that where protease inhibitors were concerned,
GM and normal soybeans were equivalent.
Protease Inhibitors Do a Number on
the Pancreas
Why be concerned about protease
inhibitors? They are the reason soybeans are notoriously hard to
digest, and why soybean consumption stresses the pancreas. Because
the protease inhibitors in soy inhibit the protease enzyme we need to
digest protein, the pancreas has to work overtime to produce more. If
this happens only occasionally, the pancreas quickly recovers. But
if soy is consumed day after day, week after week, year after year,
there will be no rest for the weary pancreas. The result is an
increase of both the number of pancreatic cells (hyperplasia) and the
size of those cells (hypertrophy).
The extent of soy-caused pancreatic
hypertrophy and hyperplasia varies widely from species to species in
the animal kingdom. In some soy-fed animals, the pancreas swells
quickly, in others more slowly, and in some not at all. However, all
animals — including the human animal — will suffer from the loss
of the ability to secrete sufficient enzymes if regularly consuming
protease inhibitors. That means digestive distress for nearly
everyone and growth problems for the young.
With pancreatic stress and cell
proliferation, cancer becomes a distinct possibility. Pancreatic
cancer currently ranks as the fourth leading cause of cancer deaths
of men and women in the United States, and is predicted to move into
second place by 2020. Back in the 1970s and 1980s, researchers
studying damage to the pancreas caused by protease inhibitors
noted that pancreatic cancer had then moved up to fifth place, and
suggested a soybean-protease inhibitor connection. Since then, the
rise has been even more alarming.
The fact that it has occurred along
with increased human consumption of soybeans — and over the past
decade GMO soybeans — is probably not coincidental. Association,
of course, does not prove cause and effect, but looking at the rise
of pancreatic cancer alongside the evidence of so many animal studies
is suggestive and sobering.
Irvin Liener, PhD, professor emeritus
at the University of Minnesota and the world’s leading expert on
anti-nutrients and toxins in plant foods, sums it up well, “Soybean
trypsin inhibitors do in fact pose a potential risk to humans when
soy protein is incorporated into the diet.”
