Although genetically modified foods still get a bit of a bad rap, there are actually many good reasons why modifying an organismโs genetics may be worthwhile. For example, many breeds of genetically modified foods have made themย more resistant to disease.
Itโs also possible to modify foods toย make them more nutritious. Take for example golden rice. This grain was engineered to have higher levels of vitamin A, in order toย tackle deficiencies of this nutrientย in impoverished countries.
But despite all the developments in genetically modified foods since 1994, few products have actually made it to the market. Theย continued ignorance of the general publicย about GM products alongside the reluctance of government policymakers in some countries have impeded the progress of genetically modified foods moving from the lab to the market. This is why theย regulatory approval of purple tomatoes in the US this September is so exciting.
Making a purple tomato
For the last 14 years,ย Cathie Martinย andย Eugenio Butelliย from the John Innes Centre in Norfolk, England, and their team have been working on developing the purple tomato. Their aim was to engineer a tomato that contained higher levels of anthocyanins โ which can be used alongside unmodified tomatoes to study the benefits of anthocyanins. The team chose to modify a tomato because the fruits are delicious and widely consumed.
Anthocyanins occur naturally in many fruits and vegetables that have a red, purple or blue flesh or peel โ such as blueberries, strawberries, aubergines and red cabbages. In order to produce a purple tomato, the teamย incorporated genes from snapdragons into the DNA of tomatoes.
The end result of these experiments was a unique fruit โ and not just because of itโs colour. They also succeeded in engineering tomatoes that contained high levels of anthocyanins โ comparable to the amount found in blueberries โ which is beneficial for a number of reasons.
The higher levels of anthocyanins in purple tomatoes actually work toย double their shelf lifeย compared to red tomatoes. This is because anthocyanins help to delay over-ripening and reduce the fruitโs susceptibility to fungus attack post-harvest.
Another benefitย of high levels of anthocyanins is that they attract pollinators and animals to disperse seeds, which increases reproductive success of the plants and their yield. Anthocyanins also protect plants fromย UV damageย andย protect them from pathogens, which maximises their survival.
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Anthocyanins may also be good for your health. Studies on other foods containing them have linked them to lower inflammation, lower risk of type 2 diabetes andย cancer. They may alsoย protect the brainย against disease, such as dementia.
While studies into the benefits of purple tomatoes specifically on humans are still ongoing, one study which fed cancer-prone mice food supplemented with purple tomatoes found they actuallyย lived 30% longerย compared to the mice given red tomatoes.
The future of GM
There have been a number of exciting developments in the field of GM foods in the last few years, including the firstย genome-edited GABA tomatoesย in Japan andย vitamin D enriched tomatoesย in the UK. Both were developed usingย CRISPR genome-editing technology.
Genetic modification can offer many benefits. Not only might it help us tackle the challenges of climate change by developingย more resilient crops, breeding plants with higher levels of certainย vitamins and mineralsย may potentially allow us to improve health and lower the burden of many common diseases. And, GM crops may help us ensure that everyone, regardless of where they live, has access to high-quality fresh produce thatโs good for them and the environment.
GM foods are alsoย tightly regulatedย in many countries, which means that any products which areย approved for consumptionย are safe for human, plant and animal health.
The greatest challenge now is getting more governments around the world to approve these genetically modified foods for sale. Although the UK is ahead of other countries when it comes toย regulation of gene-edited crops, itโs currently unknown whether the GM purple tomato will be offered for sale there. But itโs expected that purple tomatoes will be available for sale in the USย as soon as 2023.
Yang Yue is a PhD Candidate in Plants, Food and Health at the Quadram Institute working on a project which looks at the impact of anthocyanin-enriched food on gut and brain health. Follow Yue on Twitter @YangYue_Plant
A version of this article was posted at the Conversation and is used here with permission. Check out Conversation on Twitter @ConversationEDU
