Researchers at the University of Navarra have managed to increase the health properties of lettuce by incorporating newly synthesized selenized products in the irrigation of the plants, previously associated with mycorrhizal fungi. They have shown that the combination of both factors can favor the accumulation of the natural antioxidant components of lettuce.

To do this, scientists have used newly synthesized compounds that have also been shown to have protective effects against cancer:"The chemoprotective properties of selenium have been recognized by the academic community. In fact, in the USA they recommend selenium supplements in the per diem expenses for this purpose", explains Carmen Sanmartín, Doctor of Pharmacy.

He also adds that selenium is found naturally and in greater quantities in asparagus, Brussels sprouts, shellfish, cauliflower or broccoli, whose intake is also indicated for its preventive nature against the disease. "The biggest novelty in our work is that we have managed to improve the natural properties of different types of lettuce with selenium-rich compounds synthesized for the first time in laboratory, hence its great interest for the consumer and for the industries of the sector", explains Professor Sanmartín.

In addition, the researchers of the School of Sciences - who are part of the group of Stress Physiology in Plants associated with the CSIC - went further in this study and demonstrated that lettuce plants associated with mycorrhizal fungi further increase the nutritional value of the plants, since the fungi favor the absorption of minerals present in the soil -such as iron, zinc or copper- and alter the metabolism of the lettuce, so that it can accumulate more natural antioxidant compounds, such as carotenes, anthocyanins, phenols or vitamin C, depending on the lettuce subject .

Lettuce cultivation in selenium-contaminated soils

In addition, group at research has shown that lettuces in symbiosis with mycorrhizal fungi have lower levels of selenium in leaves than normal plants, raising the possibility of growing this mycorrhizal vegetable in soils with high levels of selenium. "In certain areas of China, for example, the cultivation of plants in soils rich in selenium leads the population to suffer selenosis, a serious disease that can even be fatal," explains Professor Nieves Goicoechea. In this case, she adds, "we have also observed that mycorrhizal lettuces grown with added selenium had a higher content of sugars and antioxidants, so that they also increased their nutritional qualities".

Researchers from the University of Alicante and the Federal University of Paraná, in Brazil, have also participated in these programs of study, published in prestigious journals of the environmental area .