A ‘leap forward in reducing our dependence on animal-based foods’. This is how you can see the latest development in tomato country, according to a comment in trade journal Nature, best call. Independently of each other, scientists from Great Britain and South Korea managed to genetically crack the ancient tomato in such a way that the fruit, in addition to vitamin C, also becomes a source of vitamin D.
About one billion people on Earth are deficient in vitamin D, a substance needed for bone maintenance and fighting infections, which is linked to less cancer and less dementia. People do make the vitamin – or more precisely, a precursor to it, which is converted into the real stuff by sunlight – but most of it has to come from food. Eggs, fish and meat, in particular.
Crops such as tomatoes also make some precursor vitamin D, but they use it as raw material for other necessary substances. Previous experiments in which people tried to open the vitamin D button further resulted in weak, small plantscompletely unfit for consumption.
Rescue precursor vitamin breakdown
Until British plant technologist Cathie Martin, who previously produced a purple tomato chock full of antioxidants, got involved. By precisely rewriting the genetics of the tomato, she managed to inhibit the breakdown of the precursor vitamin. As a result, the previtamin D accumulates, register her group Nature† In Korea, biotechnologist Sunghwa Choe of Seoul University did the same in a slightly different way, with even better results†
We are not there yet. The biggest problem is that the vitamins mainly end up in the leaves of the plant: you will have to eat five of British tomatoes to get the recommended daily amount of vitamin D, and two of Korean tomatoes. Moreover, it is questionable whether the genetic precision intervention will not be at the expense of other properties of the plant, such as its ability to survive at different temperatures or drought.
Under genetic modification rules
But see it above all as a start, writes Martin’s group. For example, the leaves may be processed into completely new, vitamin-D-rich products for vegans. Moreover, the genetics of, among other things, the potato and the aubergine are roughly the same as those of the tomato: it is quite conceivable that the trick will also work there.
‘It’s always fun to see how such a very precisely applied, simple genetic change still leads to such an important change in properties’, responds when asked plant researcher Jan Schaart (Wageningen University). He estimates that it will not add much for Western countries, with sufficient dairy, fish and meat, but it does for poorer countries.
The tomato will not be readily available in the local supermarket: in Europe, precision technology is still subject to genetic modification that is heavily regulated, warns Schaart.