# Potential of Laurel (_Laurus mobilis_ L.) Leaf Polyphenols for Modulation of Body Composition
## 1 Introduction  
In the last 5 years, there have been more people over the age of 65 than children younger than 5 years [1]. Consequently, there is growing interest in finding optimal physiological, endocrinological, nutritional, and lifestyle milieus for promoting healthy aging. Generally, normal aging involves changes in body composition including the loss of bone (osteoporosis) and muscle (s sarcopenia) mass and increased and/or redistributed body fat [2]. A new syndrome, osteosarcoma obesity/adiposity, has been identified to describe impairments of all three tissues [3, 4]. The syndrome has been widely studied, and findings have revealed that the combined condition is characterized by more damaging health outcomes than any one or two of the conditions (e.g., osteoporosis, sarcopenia, or obesity alone) [5].  
The ultimate goal of research endeavors is to find ways in which optimal lifestyle modifications, namely food choices and physical activity, could be used to either prevent or ameliorate the inevitable changes of aging [6, 7], including body composition deterioration. There is increasing evidence about the relationship between body composition and somebioactive components [8; 9; 10; 11] that could enhance the positive effects of healthy food choices and physical activity and lead to improved health during aging. In this context, different plant sources are being considered as sources of polyphenols that could be used for food fortification or as supplements.  
Laurel (_L. nohilis_ L) or bay leaf is a Mediterranean bush best known for the culinary use of its leaves, as well as for some medicinal purposes (e.g., treating various gastrointestinal and respiratory diseases), since ancient times [12]. Therefore, the leaves have been researched to a greater extent than other plant parts. They contain several metabolites, such as polyphenols, norisoprenoids, alkaloids, organic acids and volatile oils, which exhibit various biological activities responsible for the leaves' beneficial effects [13]. Among these, polyphenols are of special interest, since the laurel leaves contain a variety of such compounds, including flavonoids (flavonols, flavones, flavan-3-ols, flavanones), phenolic acids, proanthocyanidins and lignans. According to a previous literature review [14], flavonoids represent nearly 50% of laurel leaf polyphenols, kaempfer glycosides being the most abundant flavonoids. Phenolic acids (predominantly hydroxcinnamic acids) and flavones (mainly apigenin and its glycosides) account for around 20% and 15% of the laurel leaf polyphenols, respectively, while other phenolic groups are present in lower proportions. The rich polyphenic content of this Mediterranean plant indicates that the leaf extracts could possibly be used to benefit some health issues, including modulation of body composition, mainly through their proven antioxidant [15; 16; 17] and anti-inflammatory activity [18; 19], since oxidative stress and inflammation play a significant role in the deterioration of body composition [20; 21; 22; 23; 24; 25].  
Therefore, the aim of this paper was to evaluate the potential of laurel leaf extracts for modulating body composition, including bone, muscle and adipose tissues. We focused on the main components, such as kaempfer, hydroxycinnamic acids and apigenin.