Scientists in Europe transferred certain genes of snapdragons to tomatoes, creating a tomato with a dark purple color and loads of antioxidants. Researchers tested the tomatoes on cancer-prone mice; they found that a diet supplemented by purple tomato powder increased the life span of the mice compared to mice eating a standard diet or a diet supplemented with red tomato powder.
The study, by Eugenio Butelli of the John Innes Centre in England and colleagues from Germany, Italy, and the Netherlands, was published in Nature Biotechnology.
For the test, there were three groups of mutant mice, all prone to cancer. These mice typically get tumors and die young.
The first group ate a standard diet. The second group ate a powder taken from freeze-dried regular, red tomatoes. The third group ate powder from freeze-dried dark purple tomatoes.
The dark purple tomato group lived an average of 182 days, compared to 142 for the standard diet group and 146 days for the red tomato group. The maximum life span of mice who ate the standard diet was 211 days; the maximum life span of mice with the diet supplemented with purple tomato was 260 days.
The engineered tomatoes were richer in anthocyanins, which are pigments produced by plants. They are common in grapes, blackberries, blueberries, and other fruits. Research has suggested that anthocyanins are potent antioxidants and may provide a variety of health benefits, from promoting a healthy heart to fighting cancer.
"These figures argue strongly for the development of strategies to increase the levels of health promoting bioactive compounds such as anthocycanins in the fruits and vegetables people consume in substantial amounts," the researchers write.