Nanotechnology in Food & Agriculture - denix

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microparticles can be taken up through
broken or damaged skin (Oberdörster et
al. 2005a).
Nanoparticles and the link to
Crohn’s disease and immune
system dysfunction
It is well known that people with
asthma are especially susceptible to air
pollution. In effect, asthma sufferers
act as the ‘canary in the mine’, alerting
those around them that air pollution
levels are getting dangerously high.
Scientists have very recently suggested
that the growing prevalence of immune
system dysfunctions and inflammations
of the gastro intestinal tract such
as Crohn’s disease (a damaging
and chronic inflammation of the
gastrointestinal tract which can lead
to cancer) may be a similar warning
signal in relation to nanoparticles and
particles a few hundred nanometres in
size in our food (Ashwood et al. 2007;
Gatti 2004; Lomer et al. 2001; Lucarelli
et al. 2004; Schneider 2007).
Toxicity risks of nanofood additives
Very few studies have investigated
the toxicity of nanoparticle nutritional
additives. Some preliminary studies looking
at 300nm nanoparticles of iron fed to mice
have found that although the
bioavailability of iron was increased
greatly, there was no toxicity problem
(Rohner et al. 2007; Wegmüller et al.
2004). However another preliminary
experiment has shown that mice fed a
high dose of nanoparticles and even small
microparticles of zinc can suffer severe
organ damage and blood thickening
(Wang et al. 2006).
The failure of governments to require
comprehensive safety testing of Toxicity
risks in nano additives is concerning, given
that 300nm iron and zinc particles are
now marketed for fortification of foods
and beverages (eg SunActive® products
| NANOTECHNOLOGY IN FOOD & AGRICULTURE
marketed by Taiyo International). There
are also a number of companies selling
‘generic’ nano-additives, such as nano
zinc oxide, nano silica and other nanoencapsulated
active ingredients (see
Appendix A).
The potential for potent bioavailable
nano-nutritional additives to deliver
excessive doses of some vitamins
or minerals is also concerning. For
example online industry magazine Food
Processing.com reports that a United
States company is now promoting its
nano-formulated Vitamin E delivers “10
times the adult recommended daily
allowance for vitamin E can be delivered
to consumers ... without change in
taste or appearance of clear, fortified
waters and other functional beverages”
(Shelke 2007). Yet scientists recognise
that substances which are not toxic in
themselves can have a toxic effect if
consumed in excessive quantities. For
example, excessive consumption of
Vitamin A can cause adverse skeletal
effects and bone fractures in the limbs
(Downs 2003). Excessive consumption of
Vitamin B6 can cause a nerve disorder
that can lead to pain, numbness,
and weakness in the limbs; excessive
consumption of folic acid can cause
crippling neurologic damage (U.S. IOM
1998). If nano-nutritional additives and
supplements provide an excessive dose
of some vitamins and nutrients, these may
also interfere with the absorption of other
nutrients. Dr Qasim Chaudhry who leads
the nanotechnology research team at
the United Kingdom’s Central Science
Laboratory warns that nanoparticle and
nano-encapsulated food ingredients
“may have unanticipated effects, far
greater absorption than intended or
altered uptake of other nutrients, but
little, if anything, is known currently” (Parry
2006).
There is also the possibility that
nanoscale ingredients or contaminants
may themselves pose toxicity problems
that are difficult for food regulators to
identify. UK consultant Neville Craddock,
a leading expert in food safety testing,