Researchers from the John Innes Centre in Norwich have created a purple tomato which they hope may be able to help people with cancer. The scientists used two genes from the snapdragon flower to increase the qualities of tomatoes. The snapdragon flower contains high levels of antioxidant pigments called anthocyanins, known for their anti-cancer power.

Tomatoes make their own anthocyanins, but the snapdragon genes enabled the tomatoes to turn on that production to full blast, lead researcher Cathie Martin said in the article. The anthocyanins gave the tomatoes that purple color. Anthocyanins, found in particularly high levels in berries such as blackberry, cranberry and chokeberry, have been shown to help significantly slow the growth of colon cancer cells. The researchers found that anthocyanins accumulated in high concentrations within the purple tomato, accounting for about 10 percent of the dry weight of the plant’s ripened fruit.

The level of anthocyanins was about equivalent to that of blackberries, blueberries, and currants. But because of the high cost of such fruits, tomatoes might be a better source.

For the second part of the study, researchers fed a powder obtained from the purple tomatoes to mice that lacked the p53 gene, which helps protect against cancer. Cancer-prone mice that were fed the genetically altered tomatoes lived significantly longer than those who did not eat them.

Professor Cathie Martin said the experiment was “the first example of a GMO [genetically modified organism] with a trait that really offers a potential benefit for all consumers.” The next step is to test purple tomatoes on human volunteers.
The findings were published in the Oct. 26 issue of Nature Biotechnology. Researchers acknowledged the findings were preliminary.