Superfoods are gaining popularity among consumers because they serve beyond the basic nutritional needs such as vitamins and minerals and provide exceptional nutrients. These exceptional nutrients are phytonutrients or plant pigments that can prevent diseases caused by ageing, where our body loses its usual functions and slows down. These phytonutrients often come in deep colours such as red, orange, and purple. Hence, it is said that eating a colourful diet keeps us healthy. Some examples of superfoods are avocados, chia seeds, seaweeds and beetroots.
Scientists have now turned the common tomato into a superfood through genetic modification. Genetic modification or GM is a method to insert beneficial traits into crops from unrelated varieties. The usual red tomato is rich in lycopene, a plant pigment that gives the red colour to tomatoes. Scientists at UK’s John Innes Centre have modified the red tomatoes to become deep purple by adding genes from snapdragon flower and Arabidopsis (a weed). The purple pigments are anthocyanins, similarly found in blueberries.
Anthocyanins belong to a class of compounds called flavonoids. They have antioxidant effects where they destroy free radicals which are unstable molecules that damages our cells and increase the risk of diseases like cancer, cardiovascular diseases, diabetes, Alzheimer’s, Parkinson’s, cataracts and age-related macular degeneration. This makes the humble tomato a superfood.
Since the anthocyanin gene is from Snapdragon, it is not possible for scientists to use conventional breeding such as crossing or hybridisation. We know it is not possible to cross a papaya and a pineapple, right? The genes that is responsible for the production of anthocyanin in Snapdragon is spliced and inserted into tomatoes together with genes from Arabidopsis to help tomatoes produce the purple pigments. The scientist behind this tomato, Prof Cathie Martin conducted a study on mice in 2008 and found that mice that were fed with purple tomato powder as a supplement lived nearly 30 % longer than those supplemented with powder from normal tomatoes.
Many might be concerned of the safety of genetically modified foods. Any genetically modified crops require stringent testing to ensure their safety to human, animals and the environment before they are approved for cultivation and consumption. Scientists and regulators have conducted all the tests to assess the safety of purple tomatoes and found that they pose no risks to human health. Furthermore, anthocyanins have long history of safe consumption in our diet.
In 2014, the purple tomatoes were grown in Canada in a glasshouse for their juice to be extracted for further tests. Results show that they are safe and now Norfolk Plant Sciences, a US-based company is waiting for approval from the US authorities that will make the seeds available to farmers, supply fresh tomatoes and their products like sauces, juices and others to shops. This will be exciting for consumers.
The other common question from opponents of biotechnology is why not just eat other foods rich in anthocyanins like red dragon fruit, cranberry, blueberry or purple cabbage? The answer is we need a variety of foods to suit the dietary preference of consumers, availability and affordability of the foods. This is a viable option to reduce the rising risks of the diseases mentioned earlier. Scientists have developed other superfoods like pink pineapple which is already available, although not widely marketed yet. In contrast, tomatoes are widely used in the preparation of many foods and are available everywhere and are also cheap. This will naturally make the purple tomato a soon-to be available superfood affordable to everyone!