Agriculture Reference
In-Depth Information
Overall, no recent data indicate any particular risk of toxic symptoms to consumers from
natural plant toxicants, and some hypotheses, if they are confirmed, could point to organic
growing conditions as a measure that could further reduce the risk. However, since the most
effective protection is simply to stop eating a dish if it makes one feel sick, the issue of organic
production methods is of little direct significance for this aspect of food quality.
Beneficial nutritional properties or other positie impacts on
health
Direct measurements of effects on health of animals or humans
To show definitively that one farming method results in food with a beneficial effect on health
compared with food produced by a different method, it is necessary to measure something
known to be directly related to the health of the consumer. As a result of practical, financial
and ethical constraints, reported studies of this type have been primarily animal feeding
studies, short-term human intervention studies or epidemiological studies. Until now, the
results of these studies have not been particularly definitive. Several published animal feeding
studies have shown significant effects on one or the other health related aspect, as reviewed in
Woese
et
al
. (1997), O'Doherty Jensen
et
al
. (2001), Bourn and Prescott (2002), Food Standards
Agency (2002), Soil Association (2002), Williams (2002), AFSSA (2003), BMVEL (2003),
Kouba (2003), Lotter (2003) and Magkos
et
al
. (2003). However, the effects were not always
consistent, and some effects, such as the capacity of rodents to bear large litters, are difficult to
relate to human health, while the failure to detect effects in most short-term human studies
just shows that such studies are able to detect only the inf luences of treatments that affect
health substantially.
One short-term controlled-feeding study on humans did show effects on a central biomar-
ker, comparable to a substantial change in intake of vegetables (Grinder-Pedersen
et
al
. 2003),
which does indicate a definitive health benefit of the organic treatment. Unfortunately, the
study contained a design error (different varieties of vegetables were chosen from the two
systems) that substantially weakened this otherwise important conclusion. However, together
with two other recent studies, it indicates possible reasons for the failures of previously pub-
lished studies to provide clear and definitive evidence for any definitive links between produc-
tion methods and human health. The study also indicated methods for how to reach a better
understanding of the impact of food production systems on human health. These two studies
are the above-mentioned rat feeding study by Finamore
et
al
. (2004), and another recent study
(Lauridsen
et
al
. 2005).
Grinder-Pedersen
et
al
. (2003) showed that the biomarker for protein oxidation in blood
samples is sufficiently sensitive to detect differences in human subjects caused by small dif-
ferences in diet (irrespective of whether this was vegetable variety, production method or the
interaction of these factors). Therefore, it is relevant to include this biomarker in future
studies of food and health in general, and studies on the effects of production systems in par-
ticular. Similarly, Finamore
et
al
. (2004) showed that lymphocyte proliferative capacity can
differentiate between the effects of completely matched diets only differing in production
factors, although this marker is less generally applicable since it requires that the animal is
sacrificed. Lauridsen
et
al
. (2005) showed that rats fed diets constructed from materials
produced in three different production systems differed with regard to their sleep patterns
(organically fed ones slept with less interruptions during the day), content of immunoglobu-
lin A (IgA) in blood (lowest in those fed conventional feed) and accumulation of adipose
tissue (most fat was on the bodies of rats fed conventionally grown feed). Each of these studies
