Forskere enige om fordeler ved økologisk mat

27.03.2009
Den økte tilgangen på forskning på forskjellen mellom økologisk og konvensjonell mat og dyrkingsmetoder, har fått amerikanske forskere til å trekke seks konklusjoner om vitenskaplig beviste fordeler ved økologisk produksjon. -Det er viktig med slike rapporter i en tid hvor det ser ut til at mange leter etter svakheter ved økologisk produksjon, sier Reidar Andestad, daglig leder i Oikos.

Bildet: Pastasalat (Tine)

 

Et panel av vitenskapsmenn, som deltok i et symposium ved AAAS' årsmøte - American Association for the Advancement of Science - ble enige om seks konklusjoner i følge The Organic Center.

 

Vitenskapsmennene konkluderte blant annet med at økologisk produksjon resulterer i mer fruktbar jord, at plantene har høyere innhold av sekundære plantestoffer som antioksidanter og ernæringsmessig er bedre for mennesker enn konvensjonelt produsert mat. 

 

 

Reidar Andestad, daglig leder i Oikos

Økologisk mat er giftfri

Det er slike rapporter Folkehelseinstituttet og Helsedirektoratet bør lese før det neste gang uttaler at økologisk mat ikke er sunnere enn konvensjonell, sier Reidar Andestad daglig leder i Oikos.  Bare det fakta at en nesten ikke finner restsprøytestoffer i økologisk mat, er god nok grunn for bevisste forbruere til å forstå at disse produktene er bedre for helsa.  I følge Mattilsynet er det restsprøytemidler i nesten 50% av konvensjonelle frukt og grønnsaker som selges i Norge.

 

Her er oppsummeringen av symposiumet:

Organic Farming delivers healthier,

richer soil and nutritionally enhanced food

 

Apple and tomatoes

Six encouraging conclusions on the impacts of organic farming on soil quality and the nutritional content of food were reached by a panel of scientists participating in a symposium at the annual meeting of the American Association for the Advancement of Science. A growing body of sophisticated research over the last decade has compared the impacts of organic and conventional farming systems on soil and food quality: Studies of apple production demonstrate that organically farmed soils display improved soil health as measured by increased biological diversity, greater soil organic matter, and improved chemical and physical properties.

 

Enhancement of soil quality in organic apple production systems can lead to measurable improvements in fruit nutritional quality, taste, and storability. Organically farmed tomatoes have significantly higher levels of soluble solids and natural plant molecules called secondary plant metabolites, including flavonoids, lycopene, and Vitamin C. Most secondary plant metabolites are antioxidants, a class of plant compounds that have been linked to improved human health in populations that consume relatively high levels of fruit and vegetables.


 

Study of 27 cultivars

Organic farming can, under some circumstances, delay the onset of the "dilution effect." In hundreds of studies, scientists have shown that incrementally higher levels of fertilizer negatively impact the density of certain nutrients in harvested foodstuffs, hence the name, the "dilution [of nutrients] effect." Specifically, tomatoes grown with organic fertilizers maintain constant concentrations of beneficial phenolic secondary plant metabolites and antioxidants, even as fruit grow larger, whereas concentrations of these same beneficial compounds decline with increasing fruit size when the same tomato cultivar is grown using conventional methods and fertilizer.

 

Studies of 27 cultivars of organically grown spinach demonstrate significantly higher levels of flavonoids and vitamin C, and lower levels of nitrates. Nitrates in food are considered detrimental to human health as they can form carcinogenic compounds (nitrosamines) in the GI tract and can convert hemoglobin to a form that can no longer carry oxygen in the blood.


The levels of secondary plant metabolities 

The levels of secondary plant metabolites in food appear to be driven by the forms of nitrogen added to a farming system, as well as the ways in which the biological communities of organisms in the soil process nitrogen. Compared to typical conventional farms, the nitrogen cycle on organic farms is rooted in substantially more complex biological processes and soil-plant interactions, and for this reason, organic farming offers great promise in consistently producing nutrient-enriched foods.

 

Organic soil fertility methods, which use less readily available forms of nutrients, especially nitrogen, improve plant gene expression patterns in ways that lead to more efficient assimilation of nitrogen and carbon in tomatoes. This improvement in the efficiency of nutrient uptake leaves plants with more energy to produce beneficial plant secondary metabolites, compounds that promote plant health as well as human health.
 

Link:

http://www.organic-center.org/

 

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