E2 HYGIENE TRIBUNE Dental Tribune Middle East & Africa Edition | 3/2020 “Diets rich in plant foodsare increasingly associated with longevity and healthy ageing” An interview with Prof. Marcello Iriti, Milan State University, Italy. By Kasper Mussche, Dental Tribune International “The world of plants is fascinating,” Prof. Marcello Iriti says, in starting off the interview. “Since the beginning of humanity, plants have represent- ed, and still represent, an unlimited source of food and medication. Stud- ying plants is equally fascinating and stimulating,” he adds. A life scientist at the Faculty of Agricultural and Food Science of Milan State Univer- sity in Italy, Iriti mainly researches medicinal and food plants, with an emphasis on their biological activi- ties. The health benefits of such plant compounds are only just beginning to be realised, and it appears that our diet—and the Mediterranean diet in particular—may harbour some se- crets in this regard. I would like to talk about the link between the prevention of disease and nutrition. It seems that poly- phenols are key here. Can you ex- plain what they are? First of all, polyphenols are exclu- sively produced by plants, so plants and plant-based foods are naturally rich in these secondary metabolites. Polyphenols are a group of phy- to- chemicals, which are part of the plant’s immune system involved in defence against infec- tions, insect at- tacks and abiotic innate stresses—such as ultraviolet radia- tion, environmental pollutants and weather conditions. Consequently, the polyphenol levels in plants can vary depending on the harvest year, and post-harvest conditions too can further modify the polyphenol lev- els in plant foods. In recent decades, diets rich in plant foods have been increasingly associ- ated with longevity and healthy age- ing. Dietary patterns involving plen- ty of fruit, vegetables and legumes have been associated with reduced risk and incidence of chronic degen- erative diseases, such as Type 2 dia- betes, metabolic syndrome, cardio- vascular disease, neurodegenerative disorders, certain types of cancers and periodontal disease. Is it true that the Mediterranean diet, in particular, is a typical ex- ample of such a diet? The Mediterranean diet can be con- sidered the arche type of a health- promoting diet in this regard. This is due to high intake of low-fat dairy products and healthy lipids— mainly from seafood—as well as low consumption of refined sugars, red meat and saturated fats. The ben- eficial\effects of diets rich in plant foods—such as the Mediterranean one—can be ascribed, at least in part, to the huge phytochemical diversity of plant foods. Food plants typically contain hundreds of bioactive phyto chemicals, including polyphenols. Probably, polyphenols, a class of widespread phenylalanine deriva- tives, including flavonoids, stilbenes and proanthocyanidins, have been the most investigated dietary phyto- chemicals in recent decades and rep- resent a paradigm of the relationship between food and health. AD i t i r I o l l e c r a M . f o r P © Melatonin, present in red wine, is a powerful antioxidant and anti- inflammatory agent promoting bone metabolism in the oral cavity. What are some examples of food sources rich in polyphenols? All plant-derived foods and bever- ages are significant sources of poly- phenols, including fruit, vegetables, pulses, coffee, tea, cocoa and red wine. As I previously said, these me- tabolites arise from phenylalanine, an aromatic amino acid produced exclusively by plants. This implies that meat does not contain polyphe- nols, even though it is essential for a well-balanced diet. You described polyphenols as bio- active components. What does that mean for our health? Dietary polyphenols possess a num- ber of well-demonstrated biological activities, since they are powerful in vitro antioxidant, anti-inflamm tory, vaso-dilating, anti-thrombotic, an- timicrobial and anti-cancer agents. This means that they can play a role in the prevention of cardiovascular disease, neurodegenerative disor- ders and certain types of cancers. Indeed, oxidative stress and inflam- mation are mechanistically involved in the aetio-pathogenesis of the main chronic degenerative diseases, including some oral diseases, such as periodontitis. You were the first researcher to touch upon the role plant com- pounds could play in periodontal regeneration. The ultimate goal of periodontal treatment is to achieve periodontal soft- and hard-tissue regeneration. In this regard, polyphenols can be con- sidered as bone tissue protectants, suppressing osteoclast differentia- tion and activation, impairing bone resorption and improving bone anabolism–osteoblast activity and bone matrix synthesis. ÿPage E3