Diet and exercise:a match made in bone

Purpose of Review: Multiple dietary components have the potential to positively affect bone mineral density in early life and reduce loss of bone mass with aging. In addition, regular weight-bearing physical activity has a strong positive effect on bone through activation of osteocyte signaling. We will explore possible synergistic effects of dietary components and mechanical stimuli for bone health by identifying dietary components that have the potential to alter the response of osteocytes to mechanical loading. Recent Findings: Several (sub)cellular aspects of osteocytes determine their signaling towards osteoblasts and osteoclasts in response to mechanical stimuli, such as the osteocyte cytoskeleton, estrogen receptor α, the vitamin D receptor, and the architecture of the lacunocanalicular system. Potential modulators of these features include 1,25-dihydroxy vitamin D3, several forms of vitamin K, and the phytoestrogen genistein. Summary: Multiple dietary components potentially affect osteocyte function and therefore may have a synergistic effect on bone health when combined with a regime of physical activity

Vitamin B12 intake from animal foods, biomarkers, and health aspects

The EAT-Lancet commission recently suggested that transformation to healthy diets by 2050 will require a reduction of at least 50% in consumption of foods such as red meat and sugar, and a doubling in the global consumption of fruits, vegetables, nuts, and legumes. A diet rich in plant-based foods and with fewer animal source foods confers both improved health and environmental benefits. Notably, the risk of vitamin B12 deficiency increases when consuming a diet low in animal products. Humans are dependent on animal foods such as dairy products, meat, fish and eggs. Vitamin B12 deficiency is common worldwide, especially in populations with low consumption of animal foods because of low socioeconomic status, ethical reasons, or because of their lifestyle (i.e., vegans). According to the European Food Safety Authoroty, the recommended adequate intake of vitamin B12 is 4.0 µg/d for adults, and vitamin B12 requirements are higher during pregnancy and lactation. Infants and children from deficient mothers and elderly people are at risk for vitamin B12 deficiency. Diagnosis of vitamin B12 deficiency is hampered by low specificity of available biomarkers, and there is no consensus yet regarding the optimal definition of low vitamin B12 status. In general, a combination of at least two biomarkers is recommended. Therefore, this review presents an overview of vitamin B12 biochemistry and its biomarkers. We further summarize current recommendations of vitamin B12 intake, and evidence on the a

Lactulose stimulates calcium absorption in postmenopausal women

Animal studies have indicated that calcium absorption is increased by lactulose, a synthetic disaccharide. Therefore, the influence of lactulose on calcium absorption was measured in postmenopausal women who may benefit from the possible enhancing effect of lactulose on calcium absorption. Twelve postmenopausal women drank 100 ml of water containing 5 or 10 g of lactulose or a reference substance at breakfast for 9 days. The three treatments were given according to a randomized, double-blind, cross-over design, separated by two 19-day wash-out periods. On the 8th day of each treatment period, 44Ca dissolved in orange juice was drunk immediately after the solution with the study substance and just before a standard breakfast with 162 mg of carrier calcium. Within half an hour, 48Ca was given intravenously. Based on isotope ratios measured in urine collected before and until 36 h after isotope administration, true fractional calcium absorption was calculated. Calcium absorption during the treatments with the reference substance, 5 g and 10 g of lactulose was (mean ± SD) 27.7 ± 7.7, 30.0 ± 7.6, and 32.2 ± 7.0, respectively. A significant difference in calcium absorption was found between the highest dose of lactulose and the reference treatment (p < 0.01). A significant linear trend was found between the dose of lactulose and its positive effect on calcium absorption. In conclusion, in postmenopausal women a 9-day consumption of lactulose increases calcium absorption in a dose- response way. More research is warranted to explore how lactulose stimulates calcium absorption and whether it is able to improve calcium balance and/or to attenuate the rate of aging bone loss

Short-chain fructo-oligosaccharides improve magnesium absorption in adolescent girls with a low calcium intake

Consumption of fructo-oligosaccharides (FOS) has been shown to improve mineral absorption in the short term, but no long-term effects were studied in girls with a low calcium intake. Therefore, we hypothesized that short- and long-term consumption of short-chain FOS (sc-FOS) improves calcium and magnesium absorption in girls with a low habitual calcium intake. Fourteen girls aged between 12 and 14 years received, for 36 days, 10 g sc-FOS (sc-FOS) or maltodextrin (placebo). Short-chain FOS were taken daily for 8 days followed by an intermittent intake mode on 28 random days to mimic noncontinuous intake. In a crossover design, true calcium and magnesium absorption was computed on the 8th and 36th day of each treatment period from isotope enrichment in urine. In addition, the parathyroid hormone and vitamin D in serum and markers of bone resorption in urine (pyridinoline and deoxypyridinoline) were determined. Short-chain FOS increased magnesium absorption by 18% after 36 days (30.1% ± 9.1% vs 35.4% ± 12.8%). Magnesium absorption did not change after the initial 8 days of long-term sc-FOS intake. Short-chain FOS did not affect calcium absorption. In addition, sc-FOS did not affect vitamin D, parathyroid hormone, or markers of bone resorption. It is concluded that consumption of sc-FOS for 36 days stimulated magnesium absorption in girls but did not affect calcium absorption. © 2009 Elsevier Inc. All rights reserved

Gastrointestinal metabolization of human milk oligosaccharides

Breast feeding has a great impact on the growth of infants both physically and psychologically. Human breast milk is beneficial to infant health because it contains the necessary macro- and micro-nutrients for tissue accretion, repair and behavioural developments. The production of milk is a complex biological process and its composition and volume is dependent upon a variety of factors such as the health and dietary status of the mother. Moreover, it is influenced by the different stages and duration of breast feeding. Environmental factors, both global and local, may also alter lactation, milk composition and nutritional value. This handbook provides a unique and complete insight into the dietary and nutritional aspects of human breast milk. For a general understanding an overview is given of breast structure and function and lactation. Nutritional aspects are highlighted in a section on the composition of breast milk, including recent research results on breast milk and growth factors, vitamins, proteins and antigens, amongst others. Finally an analysis of both the beneficial and adverse factors relating to lactation and composition of breast milk are discussed

Gastrointestinal metabolization of human milk oligosaccharides

Breast feeding has a great impact on the growth of infants both physically and psychologically. Human breast milk is beneficial to infant health because it contains the necessary macro- and micro-nutrients for tissue accretion, repair and behavioural developments. The production of milk is a complex biological process and its composition and volume is dependent upon a variety of factors such as the health and dietary status of the mother. Moreover, it is influenced by the different stages and duration of breast feeding. Environmental factors, both global and local, may also alter lactation, milk composition and nutritional value. This handbook provides a unique and complete insight into the dietary and nutritional aspects of human breast milk. For a general understanding an overview is given of breast structure and function and lactation. Nutritional aspects are highlighted in a section on the composition of breast milk, including recent research results on breast milk and growth factors, vitamins, proteins and antigens, amongst others. Finally an analysis of both the beneficial and adverse factors relating to lactation and composition of breast milk are discussed