Browsing by Subject "bone turnover"

Background. To achieve healthier diets and to support the transition towards more sustainable food systems, animal protein needs to be replaced with plant-based protein sources as suggested by the EAT-Lancet commission. However, plant-based diets may be harmful to bone health due to lower intakes of vitamin D and calcium. Additionally, whether the different amino acid profiles of plant and animal proteins contribute to bone health has not been addressed. Objectives. The aim was to investigate whether partial replacement of red and processed meat with legumes affects bone turnover and whether the intake of individual amino acids from diverse sources play a role in this relationship. In addition, the intake of nutrients important for bone health such as vitamin D and calcium were examined. Materials and methods. The study was a six-week partly controlled randomized clinical trial carried out in a parallel design. 102 healthy men aged 20 – 65 years were stratified into two groups. The meat group consumed 760 g of boneless and cooked red and processed meat per week corresponding to 25 % of the total protein intake. The legume group consumed legume-based products corresponding to 20 % of the total protein intake and 200 g of red and processed meat per week corresponding to 5% of total protein intake. The rest of the diet was not controlled. Bone turnover and mineral metabolism markers were analyzed from the blood samples. Analysis of covariance (adjust for baseline values) was used to analyze the differences between the groups. Nutrient intake was recorded with 4-day food records and analyzed with t-test. Intakes of protein, amino acids, and bone-related nutrients were of interest. Results. No differences in bone formation (bone-specific alkaline phosphatase) or bone resorption markers (tartrate-resistant acid phosphatase 5b) were observed between the diet groups (P=0.875 and P=0.95). Neither parathyroid hormone, 25-hydroxyvitamin D, calcium, or phosphate concentrations differed between the groups (P=0.32, P=0.32, P=0.826, P=0.32, respectively). Parathyroid hormone concentrations increased (meat P=0.006; legume P< 0.001) and 25-hydroxyvitamin D concentrations decreased significantly in both groups (meat P=0.043; legume P=0.018). Protein, calcium, and vitamin D intakes did not differ between the groups at the endpoint (P=0.276, P=0.271 P=0.840, respectively). Regarding individual amino acids, methionine intake was higher in the meat group (P=0.041) whereas the legume group had higher intakes of arginine (P< 0.001), asparagine and aspartic acid (P=0.001), glutamine and glutamic acid (P=0.008), leucine (P=0.045) phenylalanine (P=0.001), proline (P=0.015), serine (P=0.046) and tyrosine (P=0.029). Mean intakes of nutrients and essential amino acids in both groups were met the recommendations. Conclusions: Our results suggest that increasing the proportion of plant-based protein by replacing red and processed meat in the diet does not cause a risk for bone health and provides adequate amounts of essential amino acids and nutrients. However, it seems that in the present study differing amino acid intakes did not contribute to bone turnover.