Biologisch geteelde voeding inderdaad gezonder.*
Biologisch geteelde groenten en fruit zijn daadwerkelijk gezonder dan niet-biologisch geteelde groenten en fruit. In een Zweeds onderzoek werd de remming van de groei van kankercellen in aardbeien bekeken. Biologisch geteelde aardbeien bevatten meer bioactieve stoffen zoals antioxidanten. Deze zijn ook belangrijk voor onze gezondheid, omdat ze de ontwikkeling van onder meer hart- en vaatziekten en kanker tegengaan. De verklaring is dat biologisch geteelde gewassen zelf meer antioxidanten moeten ontwikkelen, omdat die ook een belangrijk onderdeel vormen van hun eigen natuurlijke afweersysteem.
A
new landmark study shows that organic strawberry extracts inhibited the
proliferation of cancer cells more effectively than conventional strawberry
extracts.
What
is it about organically grown plants that make them rich in secondary
metabolites off the main track, which are great for fighting diseases like
cancer? Many of these compounds are actually part and parcel of the plant’s
own defence against pests and disease.
Bengt
Lundegardh and Anna Martensson [8] at the University of Agricultural Sciences
Uppsala Sweden believe that the benefits of organically grown foods have a lot
to with activating the plant’s defence mechanisms to synthesize its own
protective agents because synthetic pesticides are excluded. An active
soil where plants and microbes interact also facilitates the exchange of
metabolic compounds such as vitamins and cofactors. In addition, organically
grown foods have a richer mineral content, on account of a more balanced
nutrient uptake in the absence of artificial fertilizers, which would have
provided excesses of easily available nutrients such as nitrates.
Bioactive
compounds in foods, especially the plant phenolic antioxidants, are well known
to prevent cancer and cardiovascular disease [9]. Phenolics are present in many
crops, particularly fruits, and it has become clear that organic foods are
richer in cancer fighting antioxidants [10, 11].
Organic
strawberry extracts stop cancer cells
Strawberries
have been studied extensively for their cancer fighting ability and that is
where the benefits of organic fruit cultivation shine through. Swedish
researchers at Swedish University of Agricultural Sciences, Alnarp, and
Lund University compared extracts of five organic and conventional
cultivars for their ability to inhibit the proliferation of human colon and
breast cancer cells. They found that extracts from organically grown
strawberries inhibited cell proliferation more effectively than extracts from
the conventionally grown ones, and in both types of cancer cells [12].
The
strawberry extracts decreased cell proliferation in a dose-dependent manner
between 0.025 to 0.5 percent dry weight of extract to volume of cell culture. At
the highest concentration, the organic extracts inhibited proliferation of colon
cancer (HT29) cells by 60 percent and breast cancer (MCF-7) cells by 53.1
percent; the corresponding values for conventional strawberry extracts were 49.7
percent and 37.9 percent respectively. The differences between conventional and
organic were statistically highly significant.
The
most effective extracts at inhibiting cell proliferation contained 48 percent
more ascorbate and 5 times more dehydroascorbate. (Vitamin C is ascorbate plus
dehydroascorbate.) The organic strawberries also had more antioxidants and a
higher ratio of ascorbate to dehydroascorbate.
Compost
as a soil supplement increased the level of antioxidant compounds in
strawberries [13]. The strawberry extracts, rich in vitamin C and
antioxidants, were found to interfere with the mitogen-activated protein kinase
(MAPK) signaling cascade that leads to cell division, and to suppress cancer
cell proliferation and transformation [14].
These latest findings on organic strawberries are in line with those on other organic fruits. Organic yellow plums were found to be richer in phenolic acids when grown in natural meadow or with a ground cover of clover than conventionally grown plums [15]. Plum and clover extracts induced apoptosis (cell death) and reduced the viability of human liver cancer cells [16]. (Nov. 2006)