Tomatoes engineered to have higher levels of antioxidants protect cancer-prone mutant mice from the disease. The study published online this week in Nature Biotechnology suggests that including such foods in our diet could help to promote health and wellbeing.

Anthocyanins ? antioxidant pigments produced by plants ? can offer protection from a range of human diseases. Cathie Martin and colleagues transfer factors from snapdragon into tomatoes to increase production of these antioxidants. The resulting fruit are deep purple in colour and contain levels of anthocyanins higher than those previously engineered in crops.

The team finds that feeding cancer-susceptible mice a diet supplemented with purple tomato powder significantly prolongs their lifespan. Human health benefits have been attributed to eating anthocyanin-rich foods, such as blackberries and blueberries. Transgenic tomatoes might be an easier way to supplement dietary intake of antioxidants.