**1. Introduction**

Plant sterols are bioactive phytocompounds with a molecular structure similar to cholesterol [1]. The absorption of dietary cholesterol from diets rich in phytosterols is reduced by various mechanisms, mainly associated with the displacement of cholesterol from lipid micelles [2]. To date, more than 250 phytosterols have been identified, which include plant sterols and their saturated forms, stanols [3,4]. In various food sources, β-sitosterol is predominant and accounts for approximately 80% of the phytosterol intake in the diet [5]. Clinical evidence shows that phytosterols have a moderate LDL- and triglyceride-lowering effect [6,7]. Phytosterols are also considered moderately active antioxidants [8] and have immunomodulatory properties [9]. Sitosterol may suppress obesity-related chronic inflammation by reducing circulating interleukin-6 and TNF-α [10]. A growing body of evidence suggests that phytosterols may be an alternative and/or complementary therapy

**Citation:** Witkowska, A.M.; Wa´skiewicz, A.; Zujko, M.E.; Miro ´nczuk-Chodakowska, I.; Cicha-Mikołajczyk, A.; Drygas, W. Assessment of Plant Sterols in the Diet of Adult Polish Population with the Use of a Newly Developed Database. *Nutrients* **2021**, *13*, 2722. https://doi.org/10.3390/nu13082722

Academic Editors: Massimo Lucarini and Alessandra Durazzo

Received: 28 May 2021 Accepted: 4 August 2021 Published: 7 August 2021

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for patients with obesity and diabetes [3]. The consumption of naturally occurring plant sterols has been found to be associated with a lower risk of first myocardial infarction in men [11]. In addition, high doses of plant sterols in the diet, especially β-sitosterol, have been found to prevent the development of cancer [12,13].

Food sources with the highest plant sterol content include vegetable oils, mainly corn oil (746 mg/100 g), and sesame seeds (714 mg/100 g) [14]. A good source of phytosterols is nuts, which provide 30–220 mg/100 g of phytosterols, and cereals that contain phytosterols in the amount of 35–198 mg/100 g [15]. Vegetables contain smaller amounts of phytosterols, with 4–40 mg/100 g, and fruits contain 4–24 mg/100 g [15]. Consumption studies have shown that due to the frequency and volume of consumption, the suppliers of plant sterols are mainly bread, cereals, fats, and vegetables [3,5]. As studies show, population intakes of plant sterols are variable [5,11,16–21].

There is a need to develop databases of biologically active compounds to calculate population intakes [22]. Unlike the various databases on food composition, there are no comprehensive databases on plant sterols, which makes it difficult to estimate the intake of plant sterols in populations, as well as their further calculations in epidemiological studies. Earlier population-based studies used different databases prepared for individual studies with different methodologies [5,11,16–21]. Some studies used plant sterol databases [16,18,20], but others prepared individual databases based on experimental data [5,11,17,19,21]. There is currently no evaluation of plant sterols at the Polish population level, but an attempt has been made in a pilot study on a sample of students [23].

This work attempted to use international food databases, additionally supplemented by scientific data from the literature, to create a database of plant sterols, which would cover various kinds of foods and dishes consumed in Poland. The aim was to assess the size and sources of dietary plant sterols in the adult population of Poland.
