GMO Myths and Truths

3.2.2. Schrøder (2007) 23
A study on rats fed GM Bt rice found significant
differences in the GM-fed group of rats as
compared with the group fed the non-GM isogenic
line of rice. These included differences in the
distribution of gut bacterial species – the GM-fed
group had 23% higher levels of coliform bacteria.
There were also differences in organ weights
between the two groups, namely in the adrenals,
testis and uterus. The authors concluded that the
“possible toxicological findings” in their study
“most likely will derive from unintended changes
introduced in the GM rice and not from toxicity of
Bt toxin” in its natural, non-GM form. 23
The study found that the composition of the
GM rice was different from that of the non-GM
isogenic (with the same genetic background but
without the genetic modification) variety in
levels of certain minerals, amino acids, and total
fat and protein content. 23 These differences were
dismissed on the basis that they were within
the range reported for all varieties of rice in the
literature. However, comparing the GM rice to
genetically distinct, unrelated rice varieties is
scientifically flawed and irrelevant. It serves only
to mask the effects of the GM process (see 2.1.5,
2.1.6, 2.1.7).
Despite this flawed approach, the level of one
amino acid, histidine, was markedly higher in
the GM rice compared with the non-GM isogenic
variety and outside the variability range for any
rice. 23 Does this matter? No one knows, as the
required investigations have not been carried out.
What is known is that in other studies on rats, an
excess of histidine caused rapid zinc excretion 51
and severe zinc deficiency. 52
In addition, the level of the fatty acid, stearic
acid, was below the value reported in the literature
for any rice. 23
3.2.3. Kroghsbo (2008) 24
A study on rats fed GM Bt rice found a Btspecific
immune response in the non-GM-fed
control group as well as the GM-fed groups.
This unexpected finding led the researchers to
conclude that the immune response in the control
animals must have been due to their inhaling
particles of the powdered Bt toxin-containing feed
consumed by the GM-fed group. The researchers
recommended that for future tests on Bt crops,
GM-fed and control groups should be kept in
separate rooms or with separate air handling
systems. 24
3.2.4. Conclusion on the SAFOTEST
studies
The three SAFOTEST studies examined above
provide no evidence of safety for GM foods and
crops. On the other hand, they provide evidence
that:
● Over a decade after GM foods were released
into the food and feed supplies, regulators still
have not agreed on methods of assessing them
for safety
● The GM foods tested were markedly different in
composition from their non-GM counterparts
– probably due to the mutagenic or epigenetic
(producing changes in gene function) effects of
the GM process
● The GM foods tested caused unexpected,
potentially adverse effects in GM-fed animals
that should be investigated further in longterm
tests
● The authors were not able to conclude that the
GM foods tested were safe.
GMO Myths and Truths 45