By making a few genetic tweaks using CRISPR technology, scientists have designed a special sun-dried tomato that’s packed with vitamin D down to the leaves.
The pulp and skin of the fruit have been genetically engineered to contain the same levels of vitamin D as two eggs or 28 grams of tuna, both currently recommended sources of the essential nutrient.
When exposed to ultraviolet light for an hour, these provitamins were readily converted to vitamin D3.
Both the provitamin and the vitamin have potential health-related benefits.
“We’ve shown that you can biofortify tomatoes with provitamin D3 through gene editing, meaning tomatoes can be developed as a plant-based, sustainable source of vitamin D3,” said botanist Cathie Martin of The John Innes Center, an independent center for plant research. in England.
“Forty percent of Europeans are vitamin D deficient and so are a billion people worldwide. Not only are we tackling a huge health problem, but we are helping producers, because tomato leaves that are currently being thrown away can be used to make supplements from the gene-edited lines.”
Among the gene-edited tomatoes, researchers found that the edible green leaves contain 600 micrograms of provitamin D3 per gram.
That’s 60 times more than the recommended daily intake for adults.
The authors are not suggesting that people eat tomato leaves along with the meat, but rather that we use the green instead of throwing it away. For example, the leftover leaves can be ground up to make vegan vitamin D3 supplements.
If we’re smart about this, it seems that any part of the genetically engineered fruit could be used to address vitamin D deficiency.
While sun exposure is one way to increase vitamin D levels in the human body, diet is another important source. That said, there are very few foods that naturally contain the vitamin and even fewer that are vegan.
As a result, products such as milk, breakfast cereals and orange juice have been artificially fortified with vitamin D to promote public health.
However, tomatoes naturally contain some precursors of vitamin D3, known as 7-dehydrocholesterol or 7-DHC.
By turning off the genes that code for enzymes that break down 7-DHC, researchers forced the vitamin D precursor to accumulate in both unripe and ripe fruit.
This precursor can then be easily converted to vitamin D in the presence of sunlight, but it does not necessarily have to show benefits.
“For the elderly with declining levels of 7-DHC, consuming fruits biofortified with 7-DHC can directly address their deficiencies,” the authors write.
In fact, the genetic adjustments did not cause any changes in tomato growth, development or yield.
Since vitamin D deficiency is linked to an increased risk of cancer, Parkinson’s disease, depression and dementia, bioenriching fruits and vegetables with the nutrient could potentially go a long way in improving public health.
In light of the promising results, researchers are advocating that tomatoes become the next plant-based, sustainable source of vitamin D3. And they may not be the last either.
Eggplants, potatoes and peppers all have similar precursors of vitamin D3 that can be modified in similar ways to accumulate in the plants.
“The provitamin D-fortified tomatoes we’ve produced provide a much-needed plant-based source of the sunshine vitamin,” said plant scientist Jie Li, who works as a postdoctoral researcher in Martin’s lab.
“That’s great news for people who follow a plant-based, vegetarian or vegan diet, and for the growing number of people worldwide who suffer from the problem of vitamin D deficiency.”
The study is published in Nature Plants†