**5.3 Effect of rose hip on obesity**

During the last decades, obesity rates have exploded among the young and the elderly, so that we have a worldwide epidemic. The mass movements of people from the rural areas into cities have caused great changes in lifestyles and diets. So many people now sit in front of their computers, as compared with carrying out physical work. These changes in lifestyle and the accompanying diseases confer great costs to the society. To control the obesity epidemic, there is a now a great focus on diets and food supplements. Seeds from rose hip contain high amounts of tiliroside, not present in the shells [23]. In a study performed on mice, Niomiya et al [70] found that extract of the seeds of *Rosa canina* that was rich in tiliroside, as well as pure tiliroside isolated from *Rosa canina*, significantly reduced body weight and visceral fat gain after a treatment period of 14 days or less. In the same period, a reduction in plasma triglyceride and fatty acids was also observed. Not surprisingly, these desirable alterations were ascribed to tiliroside. Later the same group of researchers designed a randomized, placebo-controlled and double-blinded study on humans in which they showed that rose hip seed extract containing tiliroside given daily for 3 months resulted in a

significant reduction in abdominal visceral fat, body weight, and body mass index [71]. It was therefore concluded by the authors that rose hip seeds can be useful for the treatment of obesity in humans.

#### **5.4 Effect of rose hip on osteoporosis**

Loss of bone strength or osteoporosis has improved during the last century, possibly due to a combination of changes in our diet and our general reduction in physical activity. Osteoporosis is a serious threat to the public health system as loss of bone strength can lead to bone fractures and disabilities and in the elderly loss of height, due to loss of strength of thoracic and lumbar vertebrae. Such loss of height can limit important body functions and thereby quality of life. Bone formation is regulated by osteoblasts, which improves bone formation and osteoclasts, which facilitates destruction of calcified tissue (break down of bone structure). ROS (reactive oxygen species) are produced by osteoclasts, and ROS improves the destruction of collagen strands, which are important in bone remodeling [72, 73]. An increase in oxidants can also activate proteolytic enzymes such as elastases and metal proteinases resulting in a further damage of bone extracellular matrix [71]. Therefore, supplementation with antioxidants can support the restauration of bone mineral density (BMD). In a rat model, blueberries, rich in antioxidants, were shown to reduce the loss of BMD especially in the tibial and femoral area [71]. Extracts of different versions of rose hip have a phytochemical profile close to that of blueberry and have been suggested to play a role in preventing bone loss [74]. Indeed, rose hip was rated in the top three regarding antioxidant concentration when testing berries worldwide. And rose hip was rated at least three times more potent than blueberry (**Figure 4**) [74, 75]. In addition, rose hip also contains abundant amounts of vitamin C [23] (only one berry, Cockatoo Plum well known in Australia, is superior to rose hip regarding vitamin C content), as detailed in **Table 1**. Vitamin C (ascorbic acid) is an important player in regulating osteoblast differentiation and is important for secreting procollagen and stable collagen, which is needed for the growth of connective tissue and bone tissue [76].

Another argument for a positive role for rose hip treatment in osteoporosis is that the fruits contain a high number of polyphenols [77, 78], which are known to reduce bone loss resulting from oxidative stress [79]. A clinical study on humans showed that a subspecies of *Rosa canina* (Lito) was able to improve wrinkles of the skin [80], and it was further documented in human cartilage cells from the knee that the same rose hip subspecies supported the formation of collagen [81].

In summary: Rose hip is a very strong antioxidant, and there are indications that antioxidants can improve BMD in animal models. Rose hip can also improve bone quality from the impact of its rich sources of vitamin C, which improves the formation of collagen. Terpenes, abundant in rose hip, have also been proven to reduce bone loss, and rose hip (Lito) was also shown, in human knee cells, to inhibit the formation of MMP-1 (a metalloproteinase) known to impact bone loss. So even we still need a well-designed and large-scale clinical trial to document the impact of rose hip on bone density in humans—there are many indications that rose hip can support bone quality.
