It is a dirty reputation that the tomatoes have long dragged. Our ancestors were convinced that they could be toxic and dangerous for health, so that this fruit of a pretty bright red was shunned by the cooks. How to explain that this disastrous image stuck to her skin so long? Why do we consume it today as if nothing had happened? We tell you everything.
Tomatoes are actually part of the Solanaceae family, a large group including potatoes, eggplant or peppers, but also certain plants known for their ability to produce natural toxins. If this is also the case of tomatoes, a study published on February 19, 2025 by researchers from the University of Sichuan, in China, detailed the genetic mechanism which allows them to transform these toxins into harmless substances, thus making them specific to consumption and without danger for human health.
Some of these plants such as Belladone, Morelle or Mandrake, contain glycoalcaloids, compounds renowned for their medicinal uses as well as for their psychotropic effects, but also for their toxicity. If the potatoes, which produce them, only become dangerous when they green in the sun, tomatoes are generally consumed without danger. Inevitably, the men did not make details and quickly put the whole family in the same basket.
The tomatoes are red and it’s a good sign
You will be delighted to learn that unlike the potato tubers, tomatoes see their toxin content decrease when they ripen in the sun for a long time. A process that significantly increases their nutritional value. The process is simple: ripe fruits trigger a genetic mechanism that decreases the concentration of glycoalcaloids (toxins therefore), regulated by a protein called DML2, intervening in the modulation of the genetic expression of tomatoes.
This regulation process, demethylation, eliminates molecules likely to maintain toxic agents in the fruit. Thus, the genes responsible for the production of glycoalcaloids are inhibited, while those associated with color, sweetness and sweet taste are activated.
All these changes are not in vain and are part of a defense and survival mechanics of the plant. When they are green and immature, the high toxin content of tomatoes prevents animals from eating them prematurely, allowing seeds to develop properly. The fruit can therefore mature quietly, and the plant reproduces without danger.
Man is not completely foreign to the edibility of tomatoes. By selecting them according to their size, their flavor and texture, we have stimulated the activity of the DML2 gene, thus making modern tomatoes even safer to consume. A nice teamwork that will allow you this summer to feed almost exclusively with tomato-feta salads without any risk.
