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].