Last year we learned from researchers at UT-Austin that that fruit and vegetables are less nutritious than they were 30 years ago, due to agricultural techniques that increase their size but don’t allow them to properly develop nutrients. This year we learn from scientists at University of California that organic tomatoes have more disease-busting flavonoids than non-organic tomatoes.
In this study, the researchers measured the amounts of quercetin and kaempferol, two flavonoids, in dried tomato samples. They found that levels of quercetin were 79% higher, and kaempferol 97% higher in the organic tomatoes, compared to the non-organic ones.
Flavonoids are known to lower high blood pressure, which decreases the risk of heart disease and stroke, and are thought to prevent cancer and dementia. The UC scientists believe that the flavonoid levels depend on the quality of the soil, citing the absence of chemical fertilizers as the reason for higher levels of the compounds.
When nitrogen levels are not high enough in the soil, plants produce flavanoids as a defence mechanism. If inorganic nitrogen, which is present in everyday fertilizers, are applied to the soil, this over-fertilization may hinder flavonoid production.
Incidentally this study is forthcoming in the Journal of Agriculture and Food Chemistry, which is about:
Chemistry and biochemistry of agriculture and food along with safety, composition and processing; including feeds, pesticides, veterinary drugs, plant growth regulators, fertilizers, and other agro-chemicals with their metabolism, toxicology, and environmental fate and the chemical processes involved in nutrition, phytonutrients, flavors, and aromas.
Wow. Maybe I’ll grab my copy of Mother Earth News instead.
Photo courtesy of Wikipedia.