An increase in dietary n-3 fatty acids decreases a marker of bone resorption in humans

Flaxseed for Health and Disease: Review of Clinical Trials

BACKGROUND

Flaxseed (Linum usitatissimum) is an oil-based seed that contains high amounts of alpha-linolenic acid, linoleic acid, lignans, fiber and many other bioactive components which is suggested for a healthier life. Nowadays, flaxseed is known as a remarkable functional food with different health benefits for humans and protects against cardiovascular disease, diabetes, dyslipidemia, obesity and altogether metabolic syndrome.

METHODS

To review the bioactive components of flaxseed and their potential health effects, PubMed and Scopus were searched from commencement to July 2019. Keywords including: "flaxseed", "Linum usitatissimum", "metabolic syndrome", "obesity", "inflammation", "insulin resistance", "diabetes", "hyperlipidemia" and "menopause" were searched in the databases with varying combinations.

CONCLUSION

Consumption of flaxseed in different forms has valuable effects and protects against cardiovascular disease, hypertension, diabetes, dyslipidemia, inflammation and some other complications. Flaxseed can serve as a promising candidate for the management of metabolic syndrome to control blood lipid levels, fasting blood sugar, insulin resistance, body weight, waist circumference, body mass and blood pressure.

Therapeutic potentials and modulatory mechanisms of fatty acids in bone

Bone metabolism is a lifelong process that includes bone formation and resorption. Osteoblasts and osteoclasts are the predominant cell types associated with bone metabolism, which is facilitated by other cells such as bone marrow mesenchymal stem cells (BMMSCs), osteocytes and chondrocytes. As an important component in our daily diet, fatty acids are mainly categorized as long-chain fatty acids including polyunsaturated fatty acids (LCPUFAs), monounsaturated fatty acids (LCMUFAs), saturated fatty acids (LCSFAs), medium-/short-chain fatty acids (MCFAs/SCFAs) as well as their metabolites. Fatty acids are closely associated with bone metabolism and associated bone disorders. In this review, we summarized the important roles and potential therapeutic implications of fatty acids in multiple bone disorders, reviewed the diverse range of critical effects displayed by fatty acids on bone metabolism, and elucidated their modulatory roles and mechanisms on specific bone cell types. The evidence supporting close implications of fatty acids in bone metabolism and disorders suggests fatty acids as potential therapeutic and nutritional agents for the treatment and prevention of metabolic bone diseases.

Increased Consumption of Plant Foods Is Associated with Increased Bone Mineral Density

OBJECTIVES

To determine the relationship between plant food consumption and bone mineral density (BMD) in a healthy population when age, gender, BMI and physical activity are accounted for.

DESIGN

Cross-sectional study.

SETTING

Participants were recruited from the Sydney Adventist hospital and the University of New South Wales, Sydney, Australia.

PARTICIPANTS

33 males and 40 females (total n=73) participated in this study. The mean age was 56.1 ± 8.5 years. All participants were non-diabetic and in general good health.

MEASUREMENTS

A principle component analysis (PCA) was performed on 12 month self-report food intake data, gathered using the Cancer Council Victoria Dietary Questionnaire for Epidemiological Studies Version 2. Dual-energy X-ray absorptiometry was used to measure total BMD. Fasting plasma total protein, calcium and 25-Hydroxy Vitamin D levels were analysed by the Sydney Adventist Hospital pathology laboratory. Anthropometric measures were obtained using a standardized protocol. Self-reported physical activity levels were assessed using the International Physical Activity Questionnaire.

RESULTS

The PCA revealed three principle components. These were termed 'Meat Based', 'Junk Food' and 'Plant Based.' After controlling for age, gender, physical activity and BMI, the Plant Based component correlated positively with BMD (p=0.054, R2=0.439) and T-score (p=0.053, R2=0.221). Using a similar model no association between the Meat Based component and BMD or T-score was found. However, when the Plant Based component was included the Meat Based component correlated positively with BMD (p=0.046, R2=0.474) and T-score (p=0.046, R2=0.279). There was no significant association between the Junk Food component and BMD or T-score. People in the third Plant (927 ± 339 vs 751 ± 255 g/day, p=0.025) and Meat Based (921 ± 270 vs 676 ± 241 g/day, p=0.002) tertile had higher calcium intakes than those in the first. People in the second Plant Based tertile had higher plasma Vitamin D levels than those in the first (63.5 ± 16.8 vs. 52.3 ± 22.1 nmol/L, p=0.053) while those in the third Junk Food tertile had lower levels than those in the first (52.4 ± 18.5 vs. 65.4 ± 19.8 nmol/L, p=0.027). No association between Plant Based tertiles and protein intake was observed, however those in the third Meat Based (99.7 ± 25.1 vs. 50.9 ± 13.8 g/day, p=0.000) and Junk Food (87.4 ± 30.7 vs. 56.6 ± 22.2 g/day, p=0.000) tertile had higher protein intake compared to those in the first tertile.

CONCLUSION

In a healthy middle aged population with normal BMD, an increase in plant food consumption, either alone or in combination with a diet containing meat, is associated with improved bone mineralisation markers. This positive relationship is most likely due to the extensive range of micronutrients and phytochemicals packaged within plants.

Bone Benefits of Fish Oil Supplementation Depend on its EPA and DHA Content

The preventive effect of high-dose (9%) regular-fish oil (FO) against bone loss during aging has been demonstrated, but the effects of a low-dose (1%–4%) of a highly purified concentrated FO (CFO) has not been elucidated. The aim of this study was to determine the dose-dependent effect of a CFO against bone loss in C57BL/6 female mice during aging. Twelve-month old mice were fed with 1% and 4% CFO and 4% safflower oil (SFO) diets, including a group with a 4% regular-FO diet and a group with a lab chow diet for 12 months. Bone mineral density (BMD) was analyzed by dual-energy x-ray absorptiometry (DXA) before and after the dietary intervention. At the end of dietary intervention, bone resorption markers in serum and inflammatory markers in bone marrow and splenocytes and inflammatory signaling pathways in the bone marrow were analyzed. As compared to the 4% SFO control, 4% CFO maintained higher BMD during aging, while 1% CFO offered only a mild benefit. However, the 1% CFO fed group exhibited slightly better BMD than the 4% regular-FO fed group. BMD loss protection by CFO was accompanied by reduced levels of the bone resorption marker, TRAP, and the osteoclast-stimulating-factor, RANKL, without affecting the decoy-receptor of RANKL, osteoprotegerin (OPG). Further, CFO supplementation was associated with an increase in the production of IL-10, IL-12, and IFN-γ and a decrease in the production of TNF-α and IL-6, and the activation of NF-κB, p38 MAPK, and JNK signaling pathways. In conclusion, the supplementation of 4% CFO is very efficient in maintaining BMD during aging, whereas 1% CFO is only mildly beneficial. CFO supplementation starting at middle age may maintain better bone health during aging.

The impact of sea buckthorn oil fatty acids on human health

The beneficial properties of fatty acids have been undervalued for several years. In contraposition, new studies reveal that fatty acids have an essential role for human health. The aim of the study is to demonstrate the clinical applications of fatty acids present in sea buckthorn oil. The composition of fatty acids found in sea buckthorn (Hippophae rhamnoides) oil is unique for this species, presenting a vast range of health benefits for humans and therefore it is highly valued by both biomedicine and the cosmetic industry. In this way, we will see the clinical effect of monounsaturated, polyunsaturated and saturated fatty acids that constitute sea buckthorn oil and how they contribute to the correct function of the organism. Despite there being studies that support the positive effects of sea buckthorn fatty acids, they are limited. Hence, most of the results obtained in this review are from studies of isolated fatty acids instead of fatty acids extracted from sea buckthorn oil. These facts permit to demonstrate the effect of sea buckthorn fatty acids separately but we lost the possibility of detecting a synergic effect of all of them. More studies are necessary to certify the clinical application of the fatty acids present in sea buckthorn oil as well as discovering possible synergies between them.

Influence of omega-3 fatty acid on orthodontic tooth movement in rats: A biochemical, histological, immunohistochemical and gene expression study

OBJECTIVE

The aim of this study was to investigate the effects of omega-3 fatty acids on orthodontic tooth movement.

SETTING AND SAMPLE POPULATION

For this study, 56 12-week-old adult male Wistar albino rats from the Animal Laboratory at Adnan Menderes University, Faculty of Medicine, were used.

MATERIAL AND METHODS

Rats were randomly divided into seven groups (n = 8 each): control group (without any treatment), tooth movement groups (three groups of animals with only tooth movement) and omega groups (three groups of animals with tooth movement and omega-3 administration). Omega-3 fatty acids were administered to the rats systemically during the tooth movement period. On the 3rd, 7th and 14th days after the orthodontic tooth movement, the rats were sacrificed and biochemical, histological, immunohistochemical andgene expression examinations were performed.

RESULTS

On the 14th experimental day, the amount of tooth movement in the omega groups was significantly lower than the tooth movement groups (P = 0.012). Biochemical experimentsshowed that the omega groups had significantly lower total oxidant levels and higher total antioxidant levels compared to the tooth movement group on the 14th experimental day (P = 0.001). The levels of RANKL, IL-6 and IL-1β in the omega groups were significantly lower than the tooth movement groups on all experimental days (P < 0.05).

CONCLUSION

Systemic administration of omega-3 fatty acids showed antioxidant and antiinflammatory effects and decelerate the orthodontic tooth movement.

Fatty oil from Securidaca inappendiculata exerted therapeutic effects on adjuvant-induced arthritis in mice via suppression on fibroblast-like synoviocyte

Securidaca inappendiculata Hassk. (SI) is a medicinal plant used to treat rheumatoid arthritis (RA) in South China. A substantial amount of fatty oil was isolated from SI (SIF), however little knowledge about its chemical composition and medicinal potentials was obtained. In this study, we analyzed its chemical composition with methyl esterification based GC-MS method, and investigated the therapeutic potentials on adjuvant-induced arthritis (AA) in mice. MTT and western-blot methods were employed to investigate its effects on proliferation rate and protein expressions in MH7A cells, respectively. It was revealed SIF was mainly comprised of saturated and monosaturated fatty acids, and the two predominant compounds were palmitic acid (36.89%) and oleic acid (31.12%). Treatment with SIF at 100 mg/kg resulted in significant alleviation of AA severity in mice, together with reduced synovial hyperplasia and inflammatory infiltration in joints, and decreased levels of sialic acid, malondialdehyde and alkaline phosphatase in serum. Results from immunohistochemical assays hinted the protective effects of SIF on joints were associated to the inhibition on production of some pathological factors in synovium, including IL-1β, TNF-α and MMP-9. SIF inhibited the proliferation of MH7A cells in a concentration dependent manner, and abrogated phosphorylation of p65 in vitro. These evidences collectively suggested SIF could suppress the pathological functions of fibroblast-like synoviocyte, and protect joints from destruction under AA conditions.

Validation of an equation predicting highly unsaturated fatty acid (HUFA) compositions of human blood fractions from dietary intakes of both HUFAs and their precursors

Proportions of omega-3 (n-3) and omega-6 (n-6) in 20- and 22-carbon highly unsaturated fatty acids with 3 or more double bonds (HUFA) accumulated in tissue HUFA (e.g., the %n-6 in HUFA) are biomarkers reflecting intakes of n-6 and n-3 fatty acids. An empirical equation, referred to here as the Lands' Equation, was developed previously to use dietary intakes of n-6 and n-3 HUFA and their 18-carbon precursors to estimate the %n-6 in HUFA of humans. From the PubMed database, we identified clinical trials reporting (a) dietary intake of at least linoleic acid (18:2n-6) and alpha-linolenic acid (18:3n-3), and (b) the amounts of at least arachidonic acid (20:4n-6), eicosapentaenoic acid (20:5n-3), and docosahexaenoic acid (22:6n-3) in lipids of plasma, serum, or red blood cell. Linear regression analyses comparing reported and predicted %n-6 in HUFA gave a correlation coefficient of 0.73 (p<0.000000) for 34 studies with 92 subject groups. These results indicate that circulating HUFA compositions can be reliably estimated from dietary intake data that not only includes n-3 and n-6 HUFA consumption, but also includes consumption of 18 carbon n-3 and n-6 precursor fatty acids.

Effects of single or combined administration of salmon calcitonin and omega-3 fatty acids vs. diclofenac sodium in sodium monoiodoacetate-induced knee osteoarthritis in male Wistar rats

BACKGROUND

There is a continuous search for a better therapy in osteoarthritis (OA) management. Therefore, this study investigated the effects of salmon calcitonin (Sct) and/or omega-3 fatty acids (N-3) relative to diclofenac sodium (DF) in induced knee osteoarthritic male Wistar rats.

METHODS

The 40 rats that were used in this study were divided into 8 groups (n=5 rats), viz: Normal control; OA control; OA+N-3; OA+Low dose of Sct (Sct.Lw); OA+High dose of Sct (Sct.Hi); OA+N-3+SCt.Lw; OA+N-3+Sct.Hi; and, OA+DF. OA was induced with 4 mg of sodium monoiodoacetate in 40 μL of saline. The solution was injected into the left knee joint space of anaesthetised rats. Sct was administered at 2.5 and 5.0 IU/kg b.w. (im), whereas N-3 and DF were administered at 200 and 1 mg/kg b.w. (p.o.), respectively. Treatments commenced 9 days after the induction of OA, and they lasted for 28 days.

RESULTS

Sct and/or N-3 significantly reduced c-telopeptide of type 1 collagen (CTX-1), collagen type 2 α-1 (C2M), malondialdehyde (MDA), uric acid (UA), and interleukin-6 (IL-6), but, significantly increased superoxide dismutase (SOD) after OA induction. Both therapies had additive effects on C2M, MDA, SOD, and catalase (CAT), but, non-additive actions on UA, IL-6, and CTX-1. Like the Sct and N-3, DF significantly reduced CTX-1, C2M, UA, and IL-6. However, it had no significant effect on SOD and MDA, even though it significantly reduced CAT activity. None of the therapies had significant effect on total alkaline phosphatase activity, except N-3+Sct.Lw.

CONCLUSIONS

The combined, and sometimes the single administration of Sct and N-3 proved to be better therapies in OA management than DF.

Polyphenol uses in biomaterials engineering

Polyphenols are micronutrients obtained from diet that have been suggested to play an important role in health. The health benefits of polyphenols and their protective effects in food systems as antioxidant compounds are well known and have been extensively investigated. However, their functional roles as a "processing cofactor" in tissue engineering applications are less widely known. This review focuses on the functionality of polyphenols and their application in biomaterials. Polyphenols have been used to stabilize collagen and to improve its resistance to degradation in biological systems. Therefore, they have been proposed to improve the performance of biomedical devices used in cardiovascular systems by improving the mechanical properties of grafted heart valves, enhancing microcirculation through the relaxation of the arterial walls and improving the capillary blood flow and pressure resistance. Polyphenols have been found to stimulate bone formation, mineralization, as well as the proliferation, differentiation, and the survival of osteoblasts. These effects are brought about by the stimulatory effect of polyphenols on osteoblast cells and their protective effect against oxidative stress and inflammatory cytokines. In addition, polyphenols inhibit the differentiation of the osteoclast cells. Collectively, these actions lead to promote bone formation and to reduce bone resorption, respectively. Moreover, polyphenols can increase the cross-linking of dentine and hence its mechanical stability. Overall, polyphenols provide interesting properties that will stimulate further research in the bioengineering field.

Inulin supplementation reduces the negative effect of a high-fat diet rich in SFA on bone health of growing pigs

Consumption of a high-fat diet, rich in SFA, causes deterioration of bone properties. Some studies suggest that feeding inulin to animals may increase mineral absorption and positively affect bone quality; however, these studies have been carried out only on rodents fed a standard diet. The primary objective of this study was to determine the effect of inulin on bone health of pigs (using it as an animal model for humans) fed a high-fat diet rich in SFA, having an unbalanced ratio of lysine:metabolisable energy. It was hypothesised that inulin reduces the negative effects of such a diet on bone health. At 50 d of age, twenty-one pigs were randomly allotted to three groups: the control (C) group fed a standard diet, and two experimental (T and TI) groups fed a high-fat diet rich in SFA. Moreover, TI pigs consumed an extra inulin supply (7 % of daily feed intake). After 10 weeks, whole-body bone mineral content (P=0·0054) and bone mineral density (P=0·0322) were higher in pigs of groups TI and C compared with those of group T. Femur bone mineral density was highest in pigs in group C, lower in group TI and lowest in group T (P=0·001). Femurs of pigs in groups TI and C had similar, but higher, maximum strength compared with femurs of pigs in group T (P=0·0082). In conclusion, consumption of a high-fat diet rich in SFA adversely affected bone health, but inulin supplementation in such a diet diminishes this negative effect.

Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and significance - A review

Linoleic acid (LA) (n-6) and α-linolenic acid (ALA) (n-3) are essential fatty acids (EFAs) as they cannot be synthesized by humans or other higher animals. In the human body, these fatty acids (FAs) give rise to arachidonic acid (ARA, n-6), eicosapentaenoic acid (EPA, n-3), and docosahexaenoic acid (DHA, n-3) that play key roles in regulating body homeostasis. Locally acting bioactive signaling lipids called eicosanoids derived from these FAs also regulate diverse homeostatic processes. In general, ARA gives rise to pro-inflammatory eicosanoids whereas EPA and DHA give rise to anti-inflammatory eicosanoids. Thus, a proportionally higher consumption of n-3 PUFAs can protect us against inflammatory diseases, cancer, cardiovascular diseases, and other chronic diseases. The present review summarizes major sources, intake, and global consumption of n-3 and n-6 PUFAs. Their metabolism to biosynthesize long-chain PUFAs and eicosanoids and their roles in brain metabolism, cardiovascular disease, obesity, cancer, and bone health are also discussed.

Calcitonin and Omega-3 Fatty Acids Exhibit Antagonistic and Non-Additive Effects in Experimental Diabetes

Because optimising therapy for the management of diabetes mellitus remains challenging, the study investigated the effects of salmon calcitonin (Sct) and/or omega-3 fatty acids (N-3 - eicosapentaenoic acid and docosahexaenoic acid-3:2), compared to metformin, on selected biochemical parameters in male Wistar rats, in an experimental model of diabetes. Forty rats were used for this study. They were divided into eight groups of five rats each, which included: Normal control; Diabetic (D) control; D + N-3; D + low dose Sct (Sct. Lw); D + high dose Sct (Sct. Hi); D + N-3 + Sct.Lw; D + N-3 + Sct.Hi; and D + metformin. Diabetes was induced in overnight fasted rats by the administration of streptozotocin (65 mg/kg b.w., i.p.), 15 min after the administration of nicotinamide (110 mg/kg b.w., i.p.). Nine days later, Sct was administered at 2.5 and 5.0 IU/kg b.w./day (i.m.), while N-3 and metformin were administered at 200 and 180 mg/kg b.w./day (p.o.) respectively, for four weeks. Sct, N-3, and metformin significantly reduced total cholesterol, LDL-C, cortisol, c-telopeptide of type 1 collagen, and collagen type 2 alpha-1. The combined administration of Sct and N-3 had more favorable effects on triglyceride and HDL-C than either monotherapy. Unlike metformin and Sct. Hi, N-3 significantly reduced alkaline phosphatase activity. Moreover, N-3 significantly suppressed the hypocalcaemic, hyperglycaemic, and insulin resistance provoking actions of Sct. Furthermore, N-3 contradicted the hepatic glycogen depletion and inhibition of nitric oxide synthesis brought about by Sct. In conclusion, N-3 demonstrated antagonistic and non-additive actions with Sct. Moreover, the effects of the combined administration of Sct and N-3 were comparable to that of metformin; therefore, they might be considered as therapeutic alternatives in diabetes.

Unsaturation level decreased in bone marrow fat of postmenopausal women with low bone density using high resolution magic angle spinning (HRMAS) 1H NMR spectroscopy

There are increasing evidences suggesting bone marrow adiposity tissue (MAT) plays a critical role in affecting both bone quantity and quality. However, very limited studies that have investigated the association between the composition of MAT and bone mineral density (BMD). The goal of this study was to quantify MAT unsaturation profile of marrow samples from post-menopausal women using ex vivo high-resolution magic angle spinning (HRMAS) proton nuclear magnetic resonance (¹H NMR) spectroscopy, and to investigate the relationship between MAT composition and BMD. Bone marrow samples were obtained by iliac crest aspiration during surgical procedures from 24 postmenopausal women (65-89years) who had hip surgery due to bone fracture or arthroplasty. Marrow fat composition parameters, in particular, unsaturation level (UL), mono-unsaturation level (MUL) and saturation level (SL), were quantified using HRMAS ¹H NMR spectroscopy. The patients were classified into three groups based on the DXA BMD T-scores: controls, osteopenia and osteoporosis. Marrow fat composition was compared between these three groups as well as between subjects with and without factures using ANOCOVA, adjusted for age. Subjects with lower BMD (n=17) had significantly lower MUL (P=0.003) and UL (P=0.039), and significantly higher SL (P=0.039) compared to controls (n=7). When separating lower BMD into osteopenia (n=9) and osteoporosis (n=8) groups, subjects with osteopenia had significantly lower MUL (P=0.002) and UL (P=0.010), and significantly higher SL (P=0.010) compared to healthy controls. No significant difference was observed between subjects with osteopenia and osteoporosis. Using HRMAS ¹H NMR, significantly lower unsaturation and significantly higher saturation levels were observed in the marrow fat of subjects with lower BMD. HRMAS ¹H NMR was shown to be a powerful tool for identifying novel MR markers of marrow fat composition that are associated with bone quality and potentially fracture, and other bone pathologies and changes after treatment. A better understanding of the relationship between bone marrow composition and bone quality in humans may identify novel treatment targets, and provide guidance on novel interventions and therapeutic strategies for bone preservation.

Effect of Altering Dietary n-6:n-3 Polyunsaturated Fatty Acid Ratio with Plant and Marine-Based Supplement on Biomarkers of Bone Turnover in Healthy Adults

Although there is accumulating evidence for a protective role of n-3 polyunsaturated fatty acids (n-3 PUFAs) on bone health, there are limited studies that examine the effect of altering dietary n-6:n-3 PUFA ratio with plant and marine sources of n-3 PUFA on bone health. Healthy adults (n = 24) were randomized into an eight-week crossover study with a four-week washout between treatments, with each subject consuming three of four diets. The four diets differed in the dietary n-6:n-3 PUFA ratios and either had an algal oil supplement added or not: (Control diet (10:1); α-linolenic acid (ALA) diet (2:1); Eicosapentaenoic acid/Docosahexaenoic acid (EPA/DHA) diet (10:1 plus supplement (S) containing EPA/DHA; Combination diet (2:1 + S)). The supplement was microalgae oil that provided 1 g EPA + DHA/day. Flaxseed oil and walnuts provided 8.6 g of ALA/day in the 2:1 diets. Serum levels of c-telopeptide (CTX), procollagen Type I N-terminal peptide, and osteocalcin showed significant correlation with age but none of the bone markers or peroxisomal proliferator-activated receptor-γ mRNA expression was significantly different between the diets. Serum CTX was negatively associated with red blood cell membrane linoleic acid and ALA and positively associated with membrane DHA. Neither altering dietary n-6:n-3 PUFA ratio from a 10:1 to a 2:1 ratio nor adding EPA/DHA supplement significantly changed bone turnover in the short term in healthy adults.

Childhood cancer chemotherapy-induced bone damage: pathobiology and protective effects of resveratrol and other nutraceuticals

Intensive cancer chemotherapy causes significant bone loss, for which the mechanisms remain unclear and effective treatments are lacking. This is a significant issue particularly for childhood cancers, as the most common ones have a >75% cure rate following chemotherapy; there is an increasing population of survivors who live with chronic bone defects. Studies suggest that these defects are the result of reduced bone from increased marrow fat formation and increased bone resorption following chemotherapy. These changes probably result from altered expression/activation of regulatory molecules or pathways regulating skeletal cell formation and activity. Treatment with methotrexate, an antimetabolite commonly used in childhood oncology, has been shown to increase levels of proinflammatory/pro-osteoclastogenic cytokines (e.g., enhanced NF-κB activation), leading to increased osteoclast formation and bone resorption, as well as to attenuate Wnt signaling, leading to both decreased bone and increased marrow fat formation. In recent years, understanding the mechanisms of action and potential health benefits of selected nutraceuticals, including resveratrol, genistein, icariin, and inflammatory fatty acids, has led to preclinical studies that, in some cases, indicate efficacy in reducing chemotherapy-induced bone defects. We summarize the supporting evidence.

Suppression of NADPH Oxidase Activity May Slow the Expansion of Osteolytic Bone Metastases

Lysophosphatidic acid (LPA), generated in the microenvironment of cancer cells, can drive the proliferation, invasion, and migration of cancer cells by activating G protein-coupled LPA receptors. Moreover, in cancer cells that have metastasized to bone, LPA signaling can promote osteolysis by inducing cancer cell production of cytokines, such as IL-6 and IL-8, which can stimulate osteoblasts to secrete RANKL, a key promoter of osteoclastogenesis. Indeed, in cancers prone to metastasize to bone, LPA appears to be a major driver of the expansion of osteolytic bone metastases. Activation of NADPH oxidase has been shown to play a mediating role in the signaling pathways by which LPA, as well as RANKL, promote osteolysis. In addition, there is reason to suspect that Nox4 activation is a mediator of the feed-forward mechanism whereby release of TGF-beta from bone matrix by osteolysis promotes expression of PTHrP in cancer cells, and thereby induces further osteolysis. Hence, measures which can down-regulate NADPH oxidase activity may have potential for slowing the expansion of osteolytic bone metastases in cancer patients. Phycocyanin and high-dose statins may have utility in this regard, and could be contemplated as complements to bisphosphonates or denosumab for the prevention and control of osteolytic lesions. Ingestion of omega-3-rich flaxseed or fish oil may also have potential for controlling osteolysis in cancer patients.

Daily Intake of Milk Enriched with n-3 Fatty Acids, Oleic Acid, and Calcium Improves Metabolic and Bone Biomarkers in Postmenopausal Women

OBJECTIVE

Nutritional strategies can be effective for the prevention of menopause-related diseases, such as osteoporosis and cardiovascular disease. Our aim was to evaluate the effects of a dairy product enriched in polyunsaturated fatty acids, calcium, oleic acid, and vitamins on cardiovascular markers and bone metabolism in postmenopausal women with moderate cardiovascular risk.

METHODS

One hundred seventeen healthy postmenopausal women (aged 45 ± 7.7 years) were allocated to 2 groups: the intervention group (IG; n = 63), who consumed 0.5 L/day of a low-lactose skimmed milk enriched with 40 mg/100 mL of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA), 0.54 g/100 mL oleic acid, and vitamins, and the control group (CG; n = 54), who consumed 0.5 L/day of semiskimmed milk 0.5 L/day enriched with vitamins A and D.

RESULTS

After 12 months, in the IG there was an improvement in lipid profile: a -5.78% decrease in total cholesterol (p = 0.010), -9.79% (p = 0.004) in low-density lipoprotein (LDL) cholesterol, -9.56% (p < 0.001) in total cholesterol (TC)/high-density lipoprotein (HDL) ratio, and -3.38% in LDL/HDL ratio (p < 0.001). No changes were observed in the CG. In the IG we observed a decrease of -28.20% in high-sensitivity C-reactive protein (hs-CRP; p = 0.012). There was no effect on bone turnover markers or serum osteoprotegerin (OPG) in either of the study groups. In the IG, receptor activator of nuclear factor κB ligand (RANKL) was reduced -17.64% (p = 0.003), with no effect in the CG.

CONCLUSION

In postmenopausal women with moderate cardiovascular risk, dietary supplementation with a dairy drink enriched with fatty acids (EPA+DHA), oleic acid, minerals, and vitamins induces a positive effect on cardiovascular risk and parameters of bone metabolism. Its regular consumption may be a useful nutritional support for postmenopausal women.

Assessment of bone turnover and bone quality in type 2 diabetic bone disease: current concepts and future directions

Substantial evidence exists that in addition to the well-known complications of diabetes, increased fracture risk is an important morbidity. This risk is probably due to altered bone properties in diabetes. Circulating biochemical markers of bone turnover have been found to be decreased in type 2 diabetes (T2D) and may be predictive of fractures independently of bone mineral density (BMD). Serum sclerostin levels have been found to be increased in T2D and appear to be predictive of fracture risk independent of BMD. Bone imaging technologies, including trabecular bone score (TBS) and quantitative CT testing have revealed differences in diabetic bone as compared to non-diabetic individuals. Specifically, high resolution peripheral quantitative CT (HRpQCT) imaging has demonstrated increased cortical porosity in diabetic postmenopausal women. Other factors such as bone marrow fat saturation and advanced glycation endproduct (AGE) accumulation might also relate to bone cell function and fracture risk in diabetes. These data have increased our understanding of how T2D adversely impacts both bone metabolism and fracture risk.

PUFAs, Bone Mineral Density, and Fragility Fracture: Findings from Human Studies

Osteoporosis is a global health problem that leads to an increased incidence of fragility fracture. Recent dietary patterns of Western populations include higher than recommended intakes of n-6 (ω-6) polyunsaturated fatty acids (PUFAs) relative to n-3 (ω-3) PUFAs that may result in a chronic state of sterile whole body inflammation. Findings from human bone cell culture experiments have revealed both benefits and detriments to bone-related outcomes depending on the quantity and source of PUFAs. Findings from observational and randomized controlled trials suggest that higher fatty fish intake is strongly linked with reduced risk of fragility fracture. Moreover, human studies largely support a greater intake of total PUFAs, total n-6 (ω-6) fatty acid, and total n-3 (ω-3) fatty acid for higher bone mineral density and reduced risk of fragility fracture. Less consistent evidence has been observed when investigating the role of long chain n-3 (ω-3) PUFAs or the ratio of n-6 (ω-6) PUFAs to n-3 (ω-3) PUFAs. Aspects to consider when interpreting the current literature involve participant characteristics, study duration, diet assessment tools, and the primary outcome measure.

The Association between the Consumption of Fish/Shellfish and the Risk of Osteoporosis in Men and Postmenopausal Women Aged 50 Years or Older

Fish rich in n-3 polyunsaturated fatty acids have been suggested to have a favorable effect on bone health, but previous epidemiologic studies have shown inconsistent results. The purpose of the present study was to investigate the hypothesis that the consumption of fish and shellfish is positively associated with bone mass and negatively associated with the risk of osteoporosis in Koreans and Americans. Men and postmenopausal women ≥50 years old from the Korean National Health and Nutrition Examination Survey 2008–2011 (n = 7154) and the National Health and Nutrition Examination Survey 2007–2010 (n = 2658) were included. There was a positive correlation between the consumption of fish and shellfish and bone mineral density (BMD) of the total femur, femoral neck, and lumbar spine in Koreans. Consistently, multivariate logistic regression analysis showed a significant association between intake of fish and shellfish and the risk of osteoporosis in Koreans but not in Americans. Consumption of fish and shellfish was 4–5 times higher in Koreans than Americans in the present study. In conclusion, intake of fish and shellfish was associated with BMD and the risk of osteoporosis in Koreans but not in Americans, suggesting that a minimum intake level of fish and shellfish might be recommended to protect against bone loss and osteoporosis.

Fish oil supplementation from 9 to 18 months of age affects the insulin-like growth factor axis in a sex-specific manner in Danish infants

Several studies have investigated the effects of fish oil (FO) on infant growth, but little is known about the effects of FO and sex on insulin-like growth factor-1 (IGF-1), the main regulator of growth in childhood. We explored whether FO v. sunflower oil (SO) supplementation from 9 to 18 months of age affected IGF-1 and its binding protein-3 (IGFBP-3) and whether the potential effects were sex specific. Danish infants (n 115) were randomly allocated to 5 ml/d FO (1·2 g/d n-3 long-chain PUFA (n-3 LCPUFA)) or SO. We measured growth, IGF-1, IGFBP-3 and erythrocyte EPA, a biomarker of n-3 LCPUFA intake and status, at 9 and 18 months. Erythrocyte EPA increased strongly with FO compared with SO (P<0·001). There were no effects of FO compared with SO on IGF-1 in the total population, but a sex×group interaction (P=0·02). Baseline-adjusted IGF-1 at 18 months was 11·1 µg/l (95 % CI 0·4, 21·8; P=0·04) higher after FO compared with SO supplementation among boys only. The sex×group interaction was borderline significant in the model of IGFBP-3 (P=0·09), with lower IGFBP-3 with FO compared with SO among girls only (P=0·03). The results were supported by sex-specific dose–response associations between changes in erythrocyte EPA and changes in IGF-1 and IGFBP-3 (both P<0·03). Moreover, IGF-1 was sex specifically associated with BMI and length. In conclusion, FO compared with SO resulted in higher IGF-1 among boys and lower IGFBP-3 among girls. The potential long-term implications for growth and body composition should be investigated further.

GPR120: A bi-potential mediator to modulate the osteogenic and adipogenic differentiation of BMMSCs

Free fatty acids display diverse effects as signalling molecules through GPCRs in addition to their involvement in cellular metabolism. GPR120, a G protein-coupled receptor for long-chain unsaturated fatty acids, has been reported to mediate adipogenesis in lipid metabolism. However, whether GPR120 also mediates osteogenesis and regulates BMMSCs remain unclear. In this study, we showed that GPR120 targeted the bi-potential differentiation of BMMSCs in a ligand dose-dependent manner. High concentrations of TUG-891 (a highly selective agonist of GPR120) promoted osteogenesis via the Ras-ERK1/2 cascade, while low concentrations elevated P38 and increased adipogenesis. The fine molecular regulation of GPR120 was implemented by up-regulating different integrin subunits (α1, α2 and β1; α5 and β3). The administration of high doses of TUG-891 rescued oestrogen-deficient bone loss in vivo, further supporting an essential role of GPR120 in bone metabolism. Our findings, for the first time, showed that GPR120-mediated cellular signalling determines the bi-potential differentiation of BMMSCs in a dose-dependent manner. Additionally, the induction of different integrin subunits was involved in the cytoplasmic regulation of a seesaw-like balance between ERK and p38 phosphorylation. These findings provide new hope for developing novel remedies to treat osteoporosis by adjusting the GPR120-mediated differentiation balance of BMMSCs.

Pros and cons of fatty acids in bone biology

Despite the growing interest in deciphering the causes and consequences of obesity-related disorders, the mechanisms linking fat intake to bone behaviour remain unclear. Since bone fractures are widely associated with increased morbidity and mortality, most notably in elderly and obese people, bone health has become a major social and economic issue. Consistently, public health system guidelines have encouraged low-fat diets in order to reduce associated complications. However, from a bone point of view, mechanisms linking fat intake to bone alteration remain quite controversial. Thus, after more than a decade of dedicated studies, this timely review offers a comprehensive overview of the relationships between bone and fatty acids. Using clinical evidences as a starting-point to more complex molecular elucidation, this work highlights the complexity of the system and reveals that bone alteration that cannot be solved simply by taking ω-3 pills. Fatty acid effects on bone metabolism can be both direct and indirect and require integrated investigations. Furthermore, even at the level of a single cell, one fatty acid is able to trigger several different independent pathways (receptors, metabolites…) which may all have a say in the final cellular metabolic response.

Association of dietary fat intake with the risk of hip fractures in an elderly Chinese population: A matched case-control study

AIM

The aim of the present study was to examine the association between dietary fat intake and the risk of hip fractures in an elderly Chinese population.

METHODS

A case-control study of 646 patients with newly diagnosed hip fractures and 646 controls, matched by age (±3 years) and sex, was carried out among elderly Chinese (55-80 years) in Guangdong, China. Their dietary fat intake was measured and calculated using a 79-item food-frequency questionnaire.

RESULTS

After adjusting for potential confounders, a dose-dependent increased risk of hip fractures was found to be associated with higher intakes of total fat, animal fat, saturated fatty acids and mono-unsaturated fatty acids (P for trend < 0.005). The adjusted odds ratios (95% confidence intervals) for hip fractures from a comparison of extreme quartiles were 1.92 (1.26-2.92) for total fat, 2.60 (1.70-3.99) for animal fat, 1.95 (1.30-2.93) for saturated fatty acids and 2.22 (1.46-3.39) for animal mono-unsaturated fatty acids, respectively. No significant association was observed for plant fat or polyunsaturated fatty acids (P for trend = 0.063 for plant fat and 0.174 for polyunsaturated fatty acids).

CONCLUSIONS

Our findings suggest that higher consumption of total fat and animal fat rich in saturated fatty acids might increase the risk of hip fractures in elderly Chinese.

Health benefits of plant-derived α-linolenic acid

α-Linolenic acid (ALA) is an n-3 (ω-3) fatty acid found mostly in plant foods such as flaxseed, walnuts, and vegetable oils, including canola and soybean oils. Most of the health benefits observed for n-3 fatty acids have been attributed to the marine-derived long-chain n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid, because of the strength of evidence from both epidemiologic studies and randomized controlled trials. Furthermore, the observed cardioprotective and other health effects of ALA have been credited to its precursor role in converting to EPA in the body. The promotion of fatty fish consumption for its documented health benefits may not be practical for those who are concerned with the unsustainability of marine sources or who avoid eating fish for a variety of reasons. ALA-rich plant sources are more abundant and may serve as a suitable alternate. It is therefore worthwhile to consider the evidence for the health benefits of ALA. The purpose of this review is to present the evidence from recent studies on the association between ALA and cardiovascular disease, type 2 diabetes, and fracture risk. The potential mechanisms that explain these associations will also be briefly discussed.

Effects of linseed oil and palm oil on growth performance, tibia fatty acid and biomarkers of bone metabolism in broilers

1. This study was conducted to determine the effects of different dietary fat sources on growth performance, tibia fatty acids and biomarkers of bone metabolism in broilers. 2. One-d-old commercial Arbor Acres broilers were fed with a maize-soya bean basal diet for 42 d, supplemented with oils according to the following 5 treatments: lard (lard group); linseed oil (linseed oil group); palm oil (palm oil group); linseed oil + palm oil (60:40 or 40:60 w/w, LP-1 group and LP-2 group, respectively). 3. No significant differences in weight gain, feed intake and gain/feed ratio were observed between the lard and linseed oil groups. Birds fed on palm oil had significantly greater weight gain and feed intake than those fed on lard or linseed oil. Growth performance in LP-1 and LP-2 was significantly greater than that of single-oil groups. 4. Tibia growth and bone characteristics were not influenced by supplementation with lard, linseed oil, or palm oil alone, but broilers fed on a mixture of fats had significantly greater tibia weight and length compared to broilers fed on linseed oil. Bone mineral density in tibia was significantly increased in LP-1 and LP-2 groups. 5. Supplementation of linseed oil alone or in combination with palm oil enhanced apparent digestibility of calcium, reduced serum calcium and increased tibia calcium concentrations. Moreover, supplementation with linseed oil alone or in combination with palm oil had a positive effect on biomarkers of bone growth. 6. The combination of linseed and palm oils was beneficial for growth performance, tibia growth and biomarkers of bone metabolism.

The effect of docosahexaenoic acid on bone microstructure in young mice and bone fracture in neonates

BACKGROUND

As low bone mineral density is a risk factor for fracture in childhood, optimizing age appropriate bone mass is recommended and might lower the impact of bone loss related to age. Consumption of omega-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic and docosahexaenoic (DHA) acids have been shown to beneficially modulate bone metabolism. The objective of this study was to determine the incidence of fracture in neonates receiving a fish compared with soybean oil-based intravenous lipid emulsion and evaluate the effect of varying dietary omega-3 PUFA consumption on growing bone in young mice.

MATERIALS AND METHODS

Eligibility criteria for the clinical study included gestational age ≤37 wk and parenteral nutrition-dependence for ≥4 wk. Radiographs were reviewed after lipid initiation to identify radiologic bone fracture. The animal study evaluated female C57/Bl6 mice randomized into one of five groups from age 3-12 wk, at which time femurs were harvested for micro-computed tomography and light microscopy analysis.

RESULTS

A lower incidence of bone fracture was found in neonates maintained on fish compared with soybean oil. In the animal study, findings suggest the DHA diet provides the best protection against trabecular bone loss as evidenced by increased bone volume fraction, increased trabecular number, and decreased trabecular separation on micro-computed tomography. These protective effects appeared to affect the bone microstructure alone.

CONCLUSIONS

The lower fracture risk observed in fish oil fed neonates in combination with the protective effects of DHA observed in the femurs of young C57/BL6 mice suggest an important role for omega-3 PUFAs on bone growth.

Fish oil in comparison to folinic acid for protection against adverse effects of methotrexate chemotherapy on bone

Methotrexate (MTX) chemotherapy is known to cause bone loss which lacks specific preventative treatments, although clinically folinic acid is often used to reduce MTX toxicity in soft tissues. This study investigated damaging effects of MTX injections (0.75 mg/kg/day for 5 days) in rats and potential protective benefits of fish oil (0.25, 0.5, or 0.75 ml/100 g/day) in comparison to folinic acid (0.75 mg/kg) in the tibial metaphysis. MTX treatment significantly reduced height of primary spongiosa and volume of trabecular bone while reducing density of osteoblasts. Consistently, MTX reduced osteogenic differentiation but increased adipogenesis of bone marrow stromal cells, accompanied by lower mRNA expression of osteogenic transcription factors Runx2 and Osx, but an up-regulation of adipogenesis-related genes FABP4 and PPAR-γ. MTX also increased osteoclast density, bone marrow osteoclast formation, and mRNA expression of proinflammatory cytokines IL-1, IL-6, TNF-α, and RANKL/OPG ratio in bone. Fish oil (0.5 or 0.75 ml/100 g) or folinic acid supplementation preserved bone volume, osteoblast density, and osteogenic differentiation, and suppressed MTX-induced cytokine expression, osteoclastogenesis, and adipogenesis. Thus, fish oil at 0.5 ml/100 g or above is as effective as folinic acid in counteracting MTX-induced bone damage, conserving bone formation, suppressing resorption and marrow adiposity, suggesting its therapeutic potential in preventing bone loss during MTX chemotherapy.

Position of the academy of nutrition and dietetics: dietary fatty acids for healthy adults

It is the position of the Academy of Nutrition and Dietetics (the Academy) that dietary fat for the healthy adult population should provide 20% to 35% of energy, with an increased consumption of n-3 polyunsaturated fatty acids and limited intake of saturated and trans fats. The Academy recommends a food-based approach through a diet that includes regular consumption of fatty fish, nuts and seeds, lean meats and poultry, low-fat dairy products, vegetables, fruits, whole grains, and legumes. These recommendations are made within the context of rapidly evolving science delineating the influence of dietary fat and specific fatty acids on human health. In addition to fat as a valuable and calorically dense macronutrient with a central role in supplying essential nutrition and supporting healthy body weight, evidence on individual fatty acids and fatty acid groups is emerging as a key factor in nutrition and health. Small variations in the structure of fatty acids within broader categories of fatty acids, such as polyunsaturated and saturated, appear to elicit different physiological functions. The Academy recognizes that scientific knowledge about the effects of dietary fats on human health is young and takes a prudent approach in recommending an increase in fatty acids that benefit health and a reduction in fatty acids shown to increase risk of disease. Registered dietitian nutritionists are uniquely positioned to translate fat and fatty acid research into practical and effective dietary recommendations.

Flaxseed enhances the beneficial effect of low-dose estrogen therapy at reducing bone turnover and preserving bone microarchitecture in ovariectomized rats

Our previous research showed greatest protection to vertebral bone mineral density and strength in ovariectomized (OVX) rats when lignan- and α-linolenic acid-rich flaxseed (FS) is combined with low-dose estrogen therapy (LD) compared with either treatment alone. This study determined the effects of combined FS+LD on serum and tissue markers of bone turnover and microarchitecture to explain our previous findings. Three-month-old OVX rats were randomized to negative control (NEG), FS, LD or FS+LD for 2 or 12 weeks, meaningful time points for determining effects on markers of bone metabolism and bone structure, respectively. Ground FS was added to the AIN-93M diet (100 g/kg diet) and LD (0.42 μg 17β-estradiol/(kg body weight·day)) was delivered by subcutaneous implant. Sham rats were included as positive control. Bone formation (e.g., osteocalcin), bone resorption (e.g., tartrate-resistant acid phosphatase-5β (TRAP-5β)), as well as osteoprotegerin (OPG) and receptor activator of nuclear factor κ-B ligand (RANKL) were analyzed from the 2-week study by commercial assays (serum) and (or) histology (vertebra). Vertebral bone microarchitecture was measured from the 12-week study using microcomputed tomography. In serum, FS+LD and LD induced lower TRAP-5β and osteocalcin, and higher OPG and OPG/RANKL ratio versus NEG and FS (p < 0.05). In vertebrae, FS+LD induced higher OPG and lower osteocalcin versus NEG (p < 0.01) and did not differ from LD and FS. FS+LD improved bone microarchitecture versus NEG, FS, and LD (p < 0.05). In conclusion, FS+LD protects bone tissue because of a reduction in bone turnover. However, elucidating the distinctive action of FS+LD on bone turnover compared with LD requires further investigation.

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Several studies have reported that the status in omega-3 polyunsaturated fatty acid (PUFA) and the omega-3/omega-6 PUFA ratio are positively related to bone health. This study aimed at examining the relationship between the status of different PUFAs and bone strength expressed by the stiffness index (SI) among indigenous women in northern Canada and Greenland, whose diets are rich in PUFAs compared to those of non-Aboriginals. Our study includes 118 Inuit women from Nuuk (Greenland), 195 Inuit women from Nunavik (Canada), and 249 Cree women of from East James Bay (Canada). Projects in Nunavik and in the Cree communities had a cross-sectional design and the Greenland project, a longitudinal design. The content of some PUFAs phospholipids of erythrocyte membranes was measured after transmethylation by gas chromatography coupled with a flame ionization detector. Stiffness index was measured by ultrasound at the right calcaneus with a water-bath Achilles Lunar instrument (Greenland) or an Achilles Insight instrument (Nunavik, East James Bay). Relations between SI and various PUFAs were studied using multiple linear regression analyses. Eicosapentaenoic acid (EPA) was positively and significantly associated with SI (log), even after adjustment for several confounders and covariates in all three projects. A high EPA status, resulting mainly from the consumption of fatty fish or marine mammal fat, seems to have a positive effect on bone strength measured by ultrasonography among Aboriginal women from three different populations.

A new insight to bone turnover: role of ω-3 polyunsaturated fatty acids

Background. Evidence has shown that long-chain polyunsaturated fatty acids (LCPUFA), especially the ω-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are beneficial for bone health and turnover. Objectives. This review summarizes findings from both in vivo and in vitro studies and the effects of LC PUFA on bone metabolism, as well as the relationship with the oxidative stress, the inflammatory process, and obesity. Results. Some studies in humans indicate that LCPUFA can increase bone formation, affect peak bone mass in adolescents, and reduce bone loss. However, the cellular mechanisms of action of the LCPUFA are complex and involve modulation of fatty acid metabolites such as prostaglandins, resolvins and protectins, several signaling pathways, cytokines, and growth factors, although in certain aspects there is still some controversy. LCPUFA affect receptor activator of nuclear factor κβ (RANK), a receptor found on the osteoclast, causing bone resorption, which controls osteoclast formation. Conclusions. Since fatty acids are an endogenous source of reactive oxygen species, free radicals alter the process of bone turnover; however, although there are clinical evidences linking bone metabolism and dietary lipids, more clinical trials are necessary to prove whether ω-3 PUFA supplementation plays a major role in bone health.

Benefits of omega-3 fatty acid against bone changes in salt-loaded rats: possible role of kidney

There is evidence that dietary fats are important components contributing in bone health and that bone mineral density is inversely related to sodium intake. Salt loading is also known to impose negative effects on renal function. The present study aimed to determine the effect of the polyunsaturated fatty acid omega-3 on bone changes imposed by salt loading, highlighting the role of kidney as a potential mechanism involved in this effect. Male Wistar rats were divided into three groups: control group, salt-loaded group consuming 2% NaCl solution as drinking water for 8 weeks, and omega-3-treated salt-loaded group receiving 1 g/kg/day omega-3 by gavage with consumption of 2% NaCl solution for 8 weeks. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded. Plasma levels of sodium, potassium, calcium, inorganic phosphorus (Pi), alkaline phosphatase (ALP), creatinine, urea, 1,25-dihydroxyvitamin D [1,25(OH)₂D₃], and transforming growth factor-beta1 (TGF-β1) were measured. The right tibia and kidney were removed for histologic examination and renal immunohistochemical analysis for endothelial nitric oxide synthase (eNOS) was performed. The results revealed that omega-3 reduced SBP, DBP, and MAP and plasma levels of sodium, potassium, Pi, creatinine, urea, and TGF-β1, but increased plasma levels of calcium, ALP, and 1,25(OH)₂D₃ as well as renal eNOS. Omega-3 increased cortical and trabecular bone thickness, decreased osteoclast number, and increased newly formed osteoid bone. Renal morphology was found preserved. In conclusion, omega-3 prevents the disturbed bone status imposed by salt loading. This osteoprotective effect is possibly mediated by attenuation of alterations in Ca²⁺, Pi, and ALP, and improvement of renal function and arterial blood pressure.

The ultrastructure of shelled and unshelled cashew nuts

Cashew nuts have many attributes, including sensory, nutritional and health appeal, which contribute to their worldwide acceptance. We demonstrate details of the microstructure of shelled and unshelled cashew kernels with regard to pericarp and cotyledon organization. This study also provides evidence of the colonization of these kernels by filamentous fungi. Nuts were examined by scanning electron and confocal scanning laser microscopy. Staining with acridine orange was performed. A tight lignified palisade layer adjacent to the exocarp surface explains the hardness of the shell's pericarp. The mesocarp contains large secretory cavities that confer a spongy property to this tissue. Papillose cells, which are responsible for secreting CNSL (cashew nutshell liquid), were observed to cover the inner wall of these cavities. Lipid components are readily released from the parenchyma and appear as oil droplets. The outer surface of the shelled samples exhibited a dense Aspergillus infestation.

Supplementation with fish oil and genistein, individually or in combination, protects bone against the adverse effects of methotrexate chemotherapy in rats

Cancer chemotherapy has been shown to induce long-term skeletal side effects such as osteoporosis and fractures; however, there are no preventative treatments. This study investigated the damaging effects of anti-metabolite methotrexate (MTX) subcutaneous injections (0.75 mg/kg BW) for five days and the potential protective benefits of daily oral gavage of fish oil at 0.5 mL/100 g BW (containing 375 mg of n-3 PUFA/100 g BW), genistein (2 mg/100 g BW), or their combination in young adult rats. MTX treatment alone significantly reduced primary spongiosa height and secondary spongiosa trabecular bone volume. Bone marrow stromal cells from the treated rats showed a significant reduction in osteogenic differentiation but an increase in adipogenesis ex vivo. Consistently, stromal cells had significantly higher mRNA levels of adipogenesis-related proliferator activator activated receptor-γ (PPAR-γ) and fatty acid binding protein (FABP4). MTX significantly increased the numbers of bone-resorbing osteoclasts and marrow osteoclast precursor cell pool while significantly enhancing the mRNA expression of receptor activator for nuclear factor kappa B ligand (RANKL), the RANKL/osteoprotegerin (OPG) ratio, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the bone. Supplementary treatment with fish oil and/or genistein significantly preserved trabecular bone volume and osteogenesis but suppressed MTX-induced adipogenesis and increases in osteoclast numbers and pro-osteoclastogenic cytokine expression. Thus, Fish oil and/or genistein supplementation during MTX treatment enabled not only preservation of osteogenic differentiation, osteoblast number and bone volume, but also prevention of MTX treatment-induced increases in bone marrow adiposity, osteoclastogenic cytokine expression and osteoclast formation, and thus bone loss.

Bone marrow fat composition as a novel imaging biomarker in postmenopausal women with prevalent fragility fractures

The goal of this magnetic resonance (MR) imaging study was to quantify vertebral bone marrow fat content and composition in diabetic and nondiabetic postmenopausal women with fragility fractures and to compare them with nonfracture controls with and without type 2 diabetes mellitus. Sixty-nine postmenopausal women (mean age 63 ± 5 years) were recruited. Thirty-six patients (47.8%) had spinal and/or peripheral fragility fractures. Seventeen fracture patients were diabetic. Thirty-three women (52.2%) were nonfracture controls. Sixteen women were diabetic nonfracture controls. To quantify vertebral bone marrow fat content and composition, patients underwent MR spectroscopy (MRS) of the lumbar spine at 3 Tesla. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry (DXA) of the hip and lumbar spine (LS) and quantitative computed tomography (QCT) of the LS. To evaluate associations of vertebral marrow fat content and composition with spinal and/or peripheral fragility fractures and diabetes, we used linear regression models adjusted for age, race, and spine volumetric bone mineral density (vBMD) by QCT. At the LS, nondiabetic and diabetic fracture patients had lower vBMD than controls and diabetics without fractures (p = 0.018; p = 0.005). However, areal bone mineral density (aBMD) by DXA did not differ between fracture and nonfracture patients. After adjustment for age, race, and spinal vBMD, the prevalence of fragility fractures was associated with -1.7% lower unsaturation levels (confidence interval [CI] -2.8% to -0.5%, p = 0.005) and +2.9% higher saturation levels (CI 0.5% to 5.3%, p = 0.017). Diabetes was associated with -1.3% (CI -2.3% to -0.2%, p = 0.018) lower unsaturation and +3.3% (CI 1.1% to 5.4%, p = 0.004) higher saturation levels. Diabetics with fractures had the lowest marrow unsaturation and highest saturation. There were no associations of marrow fat content with diabetes or fracture. Our results suggest that altered bone marrow fat composition is linked with fragility fractures and diabetes. MRS of spinal bone marrow fat may therefore serve as a novel tool for BMD-independent fracture risk assessment.

Association of n-3 polyunsaturated fatty acid intake with bone mineral density in postmenopausal women

n-3 Polyunsaturated fatty acids (n-3 fatty acids) have been shown to have a beneficial effect on bone in animal studies, although little is known about their role in bone metabolism in humans. We investigated the association between bone mineral density (BMD) and daily n-3 fatty acid intake. This cross-sectional, community-based, epidemiologic study was conducted among 205 healthy postmenopausal women (mean age 63.5 years, range 46-79). We examined BMD, serum N-terminal propeptide of type I collagen (PINP), urinary type-I collagen cross-linked-N-telopeptide (uNTX), total cholesterol, triglycerides, and high-density lipoprotein cholesterol. Nutrient intake was calculated using a food-frequency questionnaire. BMD was measured at the lumbar spine and femoral neck by dual-energy X-ray absorptiometry. Simple regression analysis showed that intake of neither n-3 fatty acid nor n-6 fatty acid was associated with age or lipid metabolism indices. However, simple regression analysis showed that n-3 fatty acid intake was positively associated with both lumbar spine BMD and femoral neck BMD. n-6 fatty acid intake was positively associated with femoral neck BMD but not lumbar spine BMD. Multiple regression analysis showed that n-3 fatty acid intake was positively associated with lumbar spine BMD after adjustment for age, BMI, duration of menopausal state, grip strength, PINP, uNTX, and intakes of calcium, vitamin D, vitamin K, and n-6 fatty acid. In conclusion, n-3 fatty acid intake was positively associated with lumbar spine BMD independent of bone resorption and serum levels of cholesterol and triglycerides in postmenopausal women.

Polyunsaturated fatty acids and calcaneal ultrasound parameters among Inuit women from Nuuk (Greenland): a longitudinal study

BACKGROUND

The traditional diet of Inuit people comprises large amounts of fish and marine mammals that are rich in omega-3 polyunsaturated fatty acids (PUFAs). Results from in vitro studies, laboratory animal experiments and population studies suggest that omega-3 PUFA intake and a high omega-3/omega-6 ratio exert a positive effect on bone health.

OBJECTIVE

This longitudinal study was conducted to examine the relationship between omega-3 and omega-6 PUFA status and quantitative ultrasound (QUS) parameters in Greenlandic Inuit women.

METHODS

The study included 118 Inuit women from Nuuk (Greenland), aged 49-64 years, whose QUS parameters measured at baseline (year 2000), along with PUFA status and covariates, and follow-up QUS measurements 2 years later (year 2002). QUS parameters [speed of sound (SOS); broadband ultrasound attenuation (BUA)] were measured at the right calcaneus with a water-bath Lunar Achilles instrument. Omega-3 and omega-6 PUFA contents of erythrocyte membrane phospholipids were measured after transmethylation by gas chromatography coupled with a flame ionization detector. Relationships between QUS parameters and different PUFAs were studied in multiple linear regression models.

RESULTS

Increasing values of EPA, DHA and the omega-3/omega-6 PUFA ratio were associated with increased BUA values measured at follow-up (year 2002). These associations were still present in models adjusted for several confounders and covariates. We found little evidence of associations between PUFAs and SOS values.

CONCLUSION

The omega-3 PUFA intake from marine food consumption seems to have a positive effect on bone intrinsic quality and strength, as revealed by higher BUA values in this group of Greenlandic Inuit women.

Update on nutrients involved in maintaining healthy bone

Osteoporosis is a leading cause of morbidity and mortality in the elderly and influences quality of life, as well as life expectancy. Currently, there is a growing interest among the medical scientists in search of specific nutrients and/or bioactive compounds of natural origin for the prevention of disease and maintenance of bone health. Although calcium and vitamin D have been the primary focus of nutritional prevention of osteoporosis, a recent research has clarified the importance of several additional nutrients and food constituents. Based on this review of the literature, supplementation with vitamins B, C, K, and silicon could be recommended for proper maintenance of bone health, although further clinical studies are needed. The results of studies on long-chain polyunsaturated fatty acids, potassium, magnesium, copper, selenium, and strontium are not conclusive, although studies in vitro and in animal models are interesting and promising.

Space flight calcium: implications for astronaut health, spacecraft operations, and Earth

The space flight environment is known to induce bone loss and, subsequently, calcium loss. The longer the mission, generally the more bone and calcium are lost. This review provides a history of bone and calcium studies related to space flight and highlights issues related to calcium excretion that the space program must consider so that urine can be recycled. It also discusses a novel technique using natural stable isotopes of calcium that will be helpful in the future to determine calcium and bone balance during space flight.

Comparison of the effects of canola oil versus sunflower oil on the biochemical markers of bone metabolism in osteoporosis

BACKGROUND

Recently, omega-3 fatty acids are in the center of attention for their potent anti-inflammatory effects. Osteoporosis as a chronic senile disease is associated with inflammation, and the role of inflammatory mediators has been demonstrated in the recent years. The beneficial effects of n-3 fatty acids on bone were proven in many animal studies, while to date, no conclusive data is available in human. The aim of this study was to evaluate the impact of n-3 fatty acids on bone biomarkers in osteoporotic women.

MATERIAL AND METHODS

Forty osteoporotic post-menopausal women were recruited in the study and randomized in receiving either 40 g canola oil or the same amount sunflower oil per day as their dietary oil for 3 months. Serum levels of osteocalcin, bone alkaline phosphatase (BALP), N telo peptide collagen (NTX) and 25- hydroxy vitamin D3 were measured at baseline and at the end of the third month in both groups.

RESULTS

In the canola oil group, BALP and NTX were increased after 3 months while Osteocalcin decreased in both groups slightly; however,none of these changes were significant. In both groups, serum vitamin D3 was increased significantly; however, this change between groups was not significant.

CONCLUSION

Canola oil did not affect bone formation and resorption significantly after 3 months consumption. Further investigations with longer follow up are recommended.

Bone health: part 1, nutrition

Nutrition, in sufficient amount and substance, is crucial for healthy growth and development of the skeleton and surrounding tissues, especially in physically active populations. Inadequate nutrition has been linked to maladies such as the female athlete triad, as well as poor training or competitive performance and increased risk of injury. Dietary choices favoring items high in quality protein of animal or plant origin, polyunsaturated fatty acids, fruits and vegetables high in potassium and fiber, and dairy products or other beverages fortified with calcium and vitamin D are essential to athletes to ensure adequate vitamin and mineral availability to the skeleton, which in turn can affect peak physical performance.