Omega-3 polyunsaturated fatty acids and skeletal health

Impact of health and lifestyle food supplements on periodontal tissues and health

According to the new classification, periodontitis is defined as a chronic multifactorial inflammatory disease associated with dysbiotic biofilms and characterized by progressive destruction of the tooth-supporting apparatus. This definition, based on the current scientific evidence, clearly indicates and emphasizes, beside the microbial component dental biofilm, the importance of the inflammatory reaction in the progressive destruction of periodontal tissues. The idea to modulate this inflammatory reaction in order to decrease or even cease the progressive destruction was, therefore, a logical consequence. Attempts to achieve this goal involve various kinds of anti-inflammatory drugs or medications. However, there is also an increasing effort in using food supplements or so-called natural food ingredients to modulate patients' immune responses and maybe even improve the healing of periodontal tissues. The aim of this chapter of Periodontology 2000 is to review the evidence of various food supplements and ingredients regarding their possible effects on periodontal inflammation and wound healing. This review may help researchers and clinicians to evaluate the current evidence and to stimulate further research in this area.

The Effects of Different Dietary Oil Sources on Broiler Chicken Bone Mineralization

This study was designed to determine the effects of dietary hazelnut oil (HO) and sunflower oil (SO) on the mineral composition of chicken femur and tibia bones. A 40-day trial was initiated with 600 1-day-old Ross 308 chickens. Initially, the chickens were randomly divided into four main groups of 150 each according to the proportion of SO and HO supplementation in their diets: control SO (25 g/kg SO), LHO (25 g/kg HO), HHO (50 g/kg HO), and MO (50 g/kg blend of 25 g/kg SO + 25 g/kg HO). Each group was further divided into six subgroups of 25 chickens. At the end of the trial, four chickens from each of the six subgroups were randomly selected and slaughtered. Their right tibia and right femur bones were isolated and analyzed for macro (Ca, P, Mg) and trace (Fe, Cu, Mn, Zn, Cr, Co, and Se) minerals in addition to ether extract and ash. The results suggest that the diets' fat concentration and fatty acid composition significantly affected the Ca, P, Mg, Fe, Cu, Cr, and Se composition of tibia bones (p < 0.01). The ether extract and ash contents of the femur bones were increased in both HHO and MO groups (p < 0.05), while Fe and Cr compositions were lower in all femur bones, except those from SO chickens (p < 0.05). The Se content of femur bones in the LHO group was higher than the other treatment groups (p < 0.05). In conclusion, the amount of oil and fatty acid in the diet affected the accumulation of Ca, P, Mg, Fe, Cu, and Cr minerals in the tibia bone. Moreover, the amount of Cr and Fe was lower in the femur and tibia bones in the group that received the HO supplement and all groups in which the amount of oil fed was increased.

Combined effects of soy isoflavone and lecithin on bone loss in ovariectomized mice

BACKGROUND/OBJECTIVES

Isoflavones (ISFs) are effective in preventing bone loss, but not effective enough to prevent osteoporosis. Mixtures of soy ISF and lecithin (LCT) were prepared and characterized in an attempt to improve the bone loss.

MATERIALS/METHODS

The daidzein (DZ) and genistein (GN) solubility in soy ISF were measured using liquid chromatography-mass spectrometry. The change in the crystalline characteristics of soy ISF in LCT was evaluated using X-ray diffraction analysis. Pharmacokinetic studies were conducted to evaluate and compare ISF bioavailability. Animal studies with ovariectomized (OVX) mice were carried out to estimate the effects on bone loss. The Student's t-test was used to evaluate statistical significance.

RESULTS

The solubility of DZ and GN in LCT was 125.6 and 9.7 mg/L, respectively, which were approximately 25 and 7 times higher, respectively, than those in water. The bioavailability determined by the area under the curve of DZ for the oral administration (400 mg/kg) of soy ISF alone and the soy ISF-LCT mixture was 13.19 and 16.09 µg·h/mL, respectively. The bone mineral density of OVX mice given soy ISF-LCT mixtures at ISF doses of 60 and 100 mg/kg daily was 0.189 ± 0.020 and 0.194 ± 0.010 g/mm³, respectively, whereas that of mice given 100 mg/kg soy ISF was 0.172 ± 0.028 g/mm³. The number of osteoclasts per bone perimeter was reduced by the simultaneous administration of soy ISF and LCT.

CONCLUSIONS

The effect of preventing bone loss and osteoclast formation by ingesting soy ISF and LCT at the same time was superior to soy ISF alone as the bioavailability of ISF may have been improved by the emulsification and solvation of LCT. These results suggest the possibility of using the combination of soy ISF and LCT to prevent osteoporosis.

Molecular Interactions between Dietary Lipids and Bone Tissue during Aging

Age-related bone disorders such as osteoporosis or osteoarthritis are a major public health problem due to the functional disability for millions of people worldwide. Furthermore, fractures are associated with a higher degree of morbidity and mortality in the long term, which generates greater financial and health costs. As the world population becomes older, the incidence of this type of disease increases and this effect seems notably greater in those countries that present a more westernized lifestyle. Thus, increased efforts are directed toward reducing risks that need to focus not only on the prevention of bone diseases, but also on the treatment of persons already afflicted. Evidence is accumulating that dietary lipids play an important role in bone health which results relevant to develop effective interventions for prevent bone diseases or alterations, especially in the elderly segment of the population. This review focuses on evidence about the effects of dietary lipids on bone health and describes possible mechanisms to explain how lipids act on bone metabolism during aging. Little work, however, has been accomplished in humans, so this is a challenge for future research.

Decreasing the Ratio of Dietary Linoleic to α-Linolenic Acid from 10 to 4 by Changing Only the Former Does Not Prevent Adiposity or Bone Deterioration in Obese Mice

BACKGROUND

Linoleic acid (LA; 18:2n-6) has been considered to promote low-grade chronic inflammation and adiposity. Studies show adiposity and inflammation are inversely associated with bone mass.

OBJECTIVES

This study tested the hypothesis that decreasing the dietary ratio of LA to α-linolenic acid (ALA, 18:3n-3), while keeping ALA constant, mitigates high-fat diet (HF)-induced adiposity and bone loss.

METHODS

Male C57BL/6 mice at 6 wk old were assigned to 4 treatment groups and fed 1 of the following diets ad libitum for 6 mo: a normal-fat diet (NF; 3.85 kcal/g and 10% energy as fat) with the ratio of the PUFAs LA to ALA at 6; or HFs (4.73 kcal/g and 45% energy as fat) with the ratio of LA to ALA at 10:1, 7:1, or 4:1, respectively. ALA content in the diets was kept the same for all groups at 1% energy. Bone structure, body composition, bone-related cytokines in serum, and gene expression in bone were measured. Data were analyzed using 1-factor ANOVA.

RESULTS

Compared with those fed the NF, mice fed the HFs had 19.6% higher fat mass (P < 0.01) and 13.5% higher concentration of serum tartrate-resistant acid phosphatase (TRAP) (P < 0.05), a bone resorption cytokine. Mice fed the HFs had 19.5% and 12.2% lower tibial and second lumbar vertebral bone mass, respectively (P < 0.01). Decreasing the dietary ratio of LA to ALA from 10 to 4 did not affect body mass, fat mass, serum TRAP and TNF-α, or any bone structural parameters.

CONCLUSIONS

These data indicate that decreasing the dietary ratio of LA to ALA from 10 to 4 by simply reducing LA intake does not prevent adiposity or improve bone structure in obese mice.

Dietary and Biological Assessment of the Omega-3 Status of Collegiate Athletes: A Cross-Sectional Analysis

Omega-3 fatty acids (ω-3 FA) are associated with cardiovascular health, brain function, reduction of inflammation, and several other physiological roles of importance to competitive athletes. The ω-3 FA status of National Collegiate Athletic Association (NCAA) Division I athletes has not been well-described. The purpose of this study was to evaluate the ω-3 FA status of NCAA Division I athletes using dietary and biological assessment methodology. Athletes from nine NCAA Division I institutions from throughout the U.S. (n = 1,528, 51% male, 34 sports represented, 19.9 ± 1.4 years of age) completed a food frequency questionnaire (FFQ) to assess ω-3 FA from diet and supplements. Omega-3 Index (O3i) was evaluated in a sub-set of these participants (n = 298, 55% male, 21 sports represented, 20.0 ± 1.3 years of age) using dried blood spot sampling. Only 6% (n = 93) of athletes achieved the Academy of Nutrition & Dietetics’ recommendation to consume 500 mg DHA+EPA per day. Use of ω-3 FA supplements was reported by 15% (n = 229) of participants. O3i was 4.33 ± 0.81%, with no participants meeting the O3i benchmark of 8% associated with the lowest risk of cardiovascular disease. Every additional weekly serving of fish or seafood was associated with an absolute O3i increase of 0.27%. Overall, sub-optimal ω-3 FA status was observed among a large, geographically diverse group of male and female NCAA Division I athletes. These findings may inform interventions aimed at improving ω-3 FA status of collegiate athletes. Further research on athlete-specific ω-3 FA requirements is needed.

Increasing Dietary Fish Oil Reduces Adiposity and Mitigates Bone Deterioration in Growing C57BL/6 Mice Fed a High-Fat Diet

BACKGROUND

Intake of total fat is linked to obesity and inversely associated with bone density in humans. Epidemiologic and animal studies show that long-chain n-3 (ω-3) PUFAs supplied as fish oil (FO) are beneficial to skeletal health.

OBJECTIVE

This study tested the hypothesis that increasing dietary FO would decrease adiposity and improve bone-related outcomes in growing obese mice.

METHODS

Male C57BL/6 mice at 6 wk old were assigned to 6 treatment groups and fed either a normal-fat diet (3.85 kcal/g and 10% energy as fat) or a high-fat diet (HF; 4.73 kcal/g and 45% energy as fat) containing either 0%, 3%, or 9% energy as FO (0FO, 3FO, and 9FO, respectively) ad libitum for 6 mo. Bone structure, body composition, and serum bone-related cytokines were measured.

RESULTS

The HF diet increased the expression of the adipose tissue tumor necrosis factor α (Tnfa) and serum concentrations of leptin and tartrate-resistant acid phosphatase (TRAP), and decreased serum concentrations of osteocalcin and bone-specific alkaline phosphatase (P < 0.05). FO decreased fat mass (P < 0.05), serum TRAP (P < 0.05), and adipose tissue Tnfa expression (P < 0.01). Bone content of long-chain n-3 PUFAs was increased and n-6 PUFAs were decreased with the elevation in dietary FO content (P < 0.01). Compared with mice fed 9FO, animals fed 3FO had higher femoral bone volume/total volume (25%), trabecular number (23%), connectivity density (82%), and bone mass of second lumbar vertebrae (12%) and lower femoral trabecular separation (-19%). Mice fed the 3FO HF diet had 42% higher bone mass than those fed the 0FO HF diet.

CONCLUSIONS

These data indicate increasing dietary FO ≤3% energy can decrease adiposity and mitigate HF diet-induced bone deterioration in growing C57BL/6 mice possibly by reducing inflammation and bone resorption. FO at 9% diet energy had no further beneficial effects on bone of obese mice.

Association of blood n-3 fatty acid with bone mass and bone marrow TRAP-5b in the elderly with and without hip fracture

The plasma n-3 fatty acid level was 26.2% lower in patients with osteoporotic hip fracture than in those with osteoarthritis. In all patients, n-3 fatty acid was positively associated with bone mineral density and inversely associated with tartrate-resistant acid phosphatase-5b level in bone marrow aspirates, reflecting the bone microenvironment.

INTRODUCTION

Despite the potential beneficial role of n-3 fatty acid (FA) on bone metabolism, the specific mechanisms underlying these effects in humans remain unclear. Here, we assessed whether the plasma n-3 level, as an objective indicator of its status, is associated with osteoporosis-related phenotypes and bone-related markers in human bone marrow (BM) samples.

METHODS

This was a case-control and cross-sectional study conducted in a clinical unit. n-3 FA in the blood and bone biochemical markers in the BM aspirates were measured by gas chromatography/mass spectrometry and immunoassay, respectively. BM fluids were collected from 72 patients who underwent hip surgery because of either osteoporotic hip fracture (HF; n = 28) or osteoarthritis (n = 44).

RESULTS

After adjusting for confounders, patients with HF had 26.2% lower plasma n-3 levels than those with osteoarthritis (P = 0.006), and each standard deviation increment in plasma n-3 was associated with a multivariate-adjusted odds ratio of 0.40 for osteoporotic HF (P = 0.010). In multivariate analyses including all patients, a higher plasma n-3 level was associated with higher bone mass at the lumbar spine (β = 0.615, P = 0.002) and total femur (β = 0.244, P = 0.045). Interestingly, the plasma n-3 level was inversely associated with the tartrate-resistant acid phosphatase-5b level (β = - 0.633, P = 0.023), but not with the bone-specific alkaline phosphatase level, in BM aspirates.

CONCLUSIONS

These findings provide clinical evidence that n-3 FA is a potential inhibitor of osteoclastogenesis that favors human bone health.

Omega-3 fatty acids and meloxicam supplementation and the incidence and histopathological changes associated with femoral head syndrome in broilers

Femoral head separation (FHS) is one of the problems commonly found in fast growing-type broilers that resulted in joint inflammation leading to lameness and poor animal welfare. This study aimed to examine the alimentary effects of omega-3 fatty acids (DHA) and meloxicam on the incidence of FHS in relation with changes in pathological features and serum concentrations of TNFα and IL1β in broilers. A total number of 1152 male day-old Cobb 500 broilers were divided into four groups. The chicks in T1 (Control) received the basal diet. Chicks in T2 to T4 were given burden of a modified speed bump, in which the chicks in T2 received the basal diet, and the chicks in T3 and T4 received 2% All-G-Rich (16% DHA) in the basal diet and meloxicam in drinking water (0.5 mg/kg BW) during Days 22–43 of age, respectively. It was demonstrated that the incidence of FHS in T4 was the smallest (P &lt; 0.05) among groups although the incidence of FHS was not increased by modified speed bump itself. Although BW (and average daily gain) in T3 was the smallest, but the incidence of FHS was not decreased. An osteochondrosis cleft during histopathological examination could be detected even in the normal gross lesions. Serum concentrations in TNFα and IL1β were not different among groups. In conclusion, meloxicam as an anti-inflammatory drug was useful to alleviate the gross pathological changes of FHS whereas DHA was not effective at the used dosage. Studies on histopathological changes at the beginning of FHS lesion are necessary.

The effect of dietary corn oil and fish oil supplementation in dogs with naturally occurring gingivitis

The aim of this randomized, double-blinded, placebo-controlled study was to evaluate if downregulation of the inflammatory response due to ingestion of high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can slow down gingivitis development, and thus delay the progression of periodontal disease (PD) in dogs. To this aim, 44 client-owned adult dogs (>1 and <8 years old) with naturally occurring PD (stages 1 and 2) were submitted to a plaque, gingivitis and calculus scoring followed by a dental cleaning procedure and collection of blood samples. The animals were then fed a canine adult maintenance diet, supplemented with either corn oil (0.00 g EPA and 0.00 g DHA) or fish oil (1.53 g EPA and 0.86 g DHA, both per 1,000 kcal ME) over the following 5 months. At the end of this period, the PD scoring and the blood sampling were repeated. The animals consuming fish oil had higher plasma levels of the longer chain (C ≥ 20) omega 3 fatty acids (p < 0.01) and similar plasma levels of alpha-linolenic acid (p = 0.53), omega 6 fatty acids (p > 0.63) and C reactive protein (p = 0.28) then the ones consuming corn oil. There were no differences between fish oil and corn oil diet supplementation on plaque (18.2 vs. 17.8, p = 0.78), calculus (10.1 vs. 11.5, p = 0.18) or gingivitis (19.3 vs. 19.0, p = 0.77) indexes. The authors conclude that supplementation with EPA + DHA does not slow down progression of PD in dogs.

Comparative Effects of the Fat Extracted from Raw and Fried Sardines Upon Rat Growth and Zinc Bioavailability

Three diets containing 8% olive oil, fresh sardine (Clupea pilchardus) oil and oil from sardines fried in olive oil were prepared. After in vitro digestion, soluble (dialysed and non-dialysed) and insoluble zinc fractions were determined. Fresh sardine oil and oil from sardines fried in olive oil provided more dialysed zinc and less insoluble zinc than 8% olive oil. Three groups of growing rats consumed the diets for 28 days. Food intake and body weight values of rats fed 8% olive oil were significantly higher than those fed fresh sardine oil and slightly lower than those fed oil from sardines fried in olive oil. Animals fed fresh sardine oil exhibited the lowest apparent zinc retention during days 5-12, but absorption efficiency increased during days 21-28 and all groups had similar final zinc absorption and retention values. Animals fed oil from sardines fried in olive oil displayed higher (days 5-12) or similar (days 21-28) apparent zinc absorption and retention values than rats fed 8% olive oil and fresh sardine oil. Hepatic zinc concentrations were higher in rats fed oil from sardines fried in olive oil than fed fresh sardine oil, while all groups showed similar spleenic concentrations. Zinc accumulation in skin was significantly higher in animals fed fresh sardine oil than in those fed oil from sardines fried in olive oil, and their total erythrocyte zinc concentrations were also higher than in rats fed oil from sardines fried in olive oil or on 8% olive oil. In conclusion, a diet high in raw sardine fatty acids can cause excessive zinc accumulation in skin and erythrocytes. However, these negative effects of sardine oil disappear after frying in olive oil.

Free Fatty Acid Receptor 4 (GPR120) Stimulates Bone Formation and Suppresses Bone Resorption in the Presence of Elevated n-3 Fatty Acid Levels

Free fatty acid receptor 4 (FFA4) has been reported to be a receptor for n-3 fatty acids (FAs). Although n-3 FAs are beneficial for bone health, a role of FFA4 in bone metabolism has been rarely investigated. We noted that FFA4 was more abundantly expressed in both mature osteoclasts and osteoblasts than their respective precursors and that it was activated by docosahexaenoic acid. FFA4 knockout (Ffar4(-/-)) and wild-type mice exhibited similar bone masses when fed a normal diet. Because fat-1 transgenic (fat-1(Tg+)) mice endogenously converting n-6 to n-3 FAs contain high n-3 FA levels, we crossed Ffar4(-/-) and fat-1(Tg+) mice over two generations to generate four genotypes of mice littermates: Ffar4(+/+);fat-1(Tg-), Ffar4(+/+);fat-1(Tg+), Ffar4(-/-);fat-1(Tg-), and Ffar4(-/-);fat-1(Tg+). Female and male littermates were included in ovariectomy- and high-fat diet-induced bone loss models, respectively. Female fat-1(Tg+) mice decreased bone loss after ovariectomy both by promoting osteoblastic bone formation and inhibiting osteoclastic bone resorption than their wild-type littermates, only when they had the Ffar4(+/+) background, but not the Ffar4(-/-) background. In a high-fat diet-fed model, male fat-1(Tg+) mice had higher bone mass resulting from stimulated bone formation and reduced bone resorption than their wild-type littermates, only when they had the Ffar4(+/+) background, but not the Ffar4(-/-) background. In vitro studies supported the role of FFA4 as n-3 FA receptor in bone metabolism. In conclusion, FFA4 is a dual-acting factor that increases osteoblastic bone formation and decreases osteoclastic bone resorption, suggesting that it may be an ideal target for modulating metabolic bone diseases.

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.

VITAL-Bone Health: rationale and design of two ancillary studies evaluating the effects of vitamin D and/or omega-3 fatty acid supplements on incident fractures and bone health outcomes in the VITamin D and OmegA-3 TriaL (VITAL)

RATIONALE

Although vitamin D is widely used to promote skeletal health, definitive data on benefits and risks of supplemental vitamin D alone on bone are lacking. Results from large, randomized controlled trials in the general population are sparse. Data on the effects of supplemental omega-3 fatty acids (FAs) on bone are also limited.

DESIGN

The VITamin D and OmegA-3 TriaL (VITAL) is a double-blind, placebo-controlled trial assessing the role of vitamin D3 (2000 IU/d) and omega-3 FA (1g/d) supplements in reducing risks of cancer and cardiovascular disease among U.S. men aged ≥50 and women aged ≥55. To comprehensively test effects of supplemental vitamin D and/or omega-3 FAs on skeletal health, the VITAL: Effects on Fractures ancillary study is determining the effects of these supplements on incident fractures among 25,875 participants enrolled in the parent trial. Study investigators adjudicate fractures through a detailed review of medical records and radiological images (hip and femur). In a complementary ancillary, VITAL: Effects on Structure and Architecture is determining the effects of supplemental vitamin D and/or omega-3 FAs on bone with detailed phenotyping during in-person visits. Comprehensive assessments of bone density, turnover, structure/architecture, body composition, and physical performance are being performed at baseline and 2 years post-randomization.

CONCLUSION

Results from these studies will clarify the relationship between supplemental vitamin D and/or omega-3 FAs on bone health outcomes, and inform clinical care and public health guidelines on the use of supplemental vitamin D for the primary prevention of fractures in women and men.

Feeding soy protein isolate and oils rich in omega-3 polyunsaturated fatty acids affected mineral balance, but not bone in a rat model of autosomal recessive polycystic kidney disease

Background

Polycystic kidney disease (PKD), a genetic disorder characterized by multiple cysts and renal failure at an early age. In children, kidney disease is often accompanied by disordered mineral metabolism, failure to achieve peak bone mass, and reduced adult height. Optimizing bone health during the growth stage may preserve against bone loss associated with early renal dysfunction in PKD. Dietary soy protein and omega-3 polyunsaturated fatty acid (n-3 PUFA) have been reported to ameliorate PKD and to promote bone health. The study objective was to determine the bone effects of feeding soy protein and/or n-3 PUFAs in a rat model of PKD.

Methods

Weanling female PCK rats (n = 12/group) were randomly assigned to casein + corn oil (Casein + CO), casein + soybean oil (Casein + SO), soy protein isolate + soybean oil (SPI + SO) or soy protein isolate + 1:1 soybean oil:salmon oil blend (SPI + SB) for 12 weeks.

Results

Rats fed SPI + SO diet had shorter (P = 0.001) femur length than casein-fed rats. Rats fed SPI + SO and SPI + SB diet had higher (P = 0.04) calcium (Ca) and phosphorus (P) retention. However, there were no significant differences in femur and tibial Ca, P or bone mass between diet groups. There were also no significant difference in bone microarchitecture measured by micro-computed tomography or bone strength determined by three-point bending test between diet groups.

Conclusions

Early diet management of PKD using SPI and/or n-3 PUFAs influenced bone longitudinal growth and mineral balance, but neither worsened nor enhanced bone mineralization, microarchitecture or strength.

Associations of polyunsaturated Fatty Acid intake with bone mineral density in postmenopausal women

A secondary analysis of cross-sectional data was analyzed from 6 cohorts (Fall 1995-Fall 1997) of postmenopausal women (n = 266; 56.6 ± 4.7 years) participating in the Bone Estrogen Strength Training (BEST) study (a 12-month, block-randomized, clinical trial). Bone mineral density (BMD) was measured at femur neck and trochanter, lumbar spine (L2-L4), and total body BMD using dual-energy X-ray absorptiometry (DXA). Mean dietary polyunsaturated fatty acids (PUFAs) intakes were assessed using 8 days of diet records. Multiple linear regression was used to examine associations between dietary PUFAs and BMD. Covariates included in the models were total energy intake, body weight at year 1, years after menopause, exercise, use of hormone therapy (HT), total calcium, and total iron intakes. In the total sample, lumbar spine and total body BMD had significant negative associations with dietary PUFA intake at P < 0.05. In the non-HT group, no significant associations between dietary PUFA intake and BMD were seen. In the HT group, significant inverse associations with dietary PUFA intake were seen in the spine, total body, and Ward's triangle BMD, suggesting that HT may influence PUFA associations with BMD. This study is registered with clinicaltrials.gov, identifier: NCT00000399.

EPA-coated titanium implants promote osteoconduction in white New Zealand rabbits

OBJECTIVES

To investigate the effect of eicosapentaenoic acid (EPA)-coated Ti implants on osteoconduction in white New Zealand rabbit mandibles.

MATERIAL AND METHODS

Sandblasted and cleansed planar titanium specimens with a size of 5 × 5 × 1 mm were coated on one side with 0.25 vol% eicosapentaenoic acid (EPA). The other side of the specimens was kept highly polished (the control side). These specimens were inserted in rabbit mandibles. Twelve rabbits were randomly assigned into three study groups (n = 4). The rabbits were sacrificed at 4, 8, and 12 weeks. The harvested specimens with the implants were assessed for new bone formation on both sides of the implant using CBCT, conventional radiographs, and the biaxial pullout test. The results were statistically analyzed by a nonparametric Kruskal-Wallis test and Friedman's test as multiple comparisons and by Brunner-Langer nonparametric mixed model approach (R Software).

RESULTS

A significant osteoconductive bone formation was found on the EPA-coated Ti implant surface (P < 0.05) at 8 weeks when compared to the polished surface (control). Biaxial pullout test results showed a significant difference (P < 0.05) after 8 and 12 weeks with a maximum force of 243.8 N, compared to 143.25 N after 4 week.

CONCLUSION

EPA implant coating promoted osteoconduction on the Ti implant surfaces, enhancing the anchorage of the implant to the surrounding bone in white New Zealand rabbits.

The use of dietary supplements to alleviate androgen deprivation therapy side effects during prostate cancer treatment

Prostate cancer (PCa), the most commonly diagnosed cancer and second leading cause of male cancer death in Western societies, is typically androgen-dependent, a characteristic that underlies the rationale of androgen deprivation therapy (ADT). Approximately 90% of patients initially respond to ADT strategies, however many experience side effects including hot flashes, cardiotoxicity, metabolic and musculoskeletal alterations. This review summarizes pre-clinical and clinical studies investigating the ability of dietary supplements to alleviate adverse effects arising from ADT. In particular, we focus on herbal compounds, phytoestrogens, selenium (Se), fatty acids (FA), calcium, and Vitamins D and E. Indeed, there is some evidence that calcium and Vitamin D can prevent the development of osteoporosis during ADT. On the other hand, caution should be taken with the antioxidants Se and Vitamin E until the basis underlying their respective association with type 2 diabetes mellitus and PCa tumor development has been clarified. However, many other promising supplements have not yet been subjected large-scale clinical trials making it difficult to assess their efficacy. Given the demographic trend of increased PCa diagnoses and dependence on ADT as a major therapeutic strategy, further studies are required to objectively evaluate these supplements as adjuvant for PCa patients receiving ADT.

Relationship between nutritional profile, measures of adiposity, and bone mineral density in postmenopausal Saudi women

BACKGROUND

Osteoporosis remains a major health problem in all developed countries and is a condition in which several dietary factors have been implicated.

OBJECTIVE

To assess the nutritional status and levels of adiposity of postmenopausal women in relation to bone mineral density.

DESIGN

A cross-sectional study in which dietary intake was estimated by a food frequency questionnaire in 300 Saudi postmenopausal women aged 46-88 years. Bone profile biochemistry (serum calcium, phosphate, parathyroid hormone [PTH], vitamin D) and bone mineral density (BMD) in 3 skeletal sites were determined for all participants.

RESULTS

Overweight and obesity were highly prevalent among the study population. No significant correlation was found between dietary calcium and vitamin D and bone mass at any site. Dietary intake of calcium and vitamin D was significantly less than the recommended levels for a large proportion of the cohort. Energy-adjusted intakes of carbohydrates, fat, protein, and unsaturated fatty acids were associated with BMD in the postmenopausal women. Age, body weight, and residency type were predictors of BMD at all sites. Serum-intact PTH was a predictor of BMD at lumbar spine and femoral neck. Waist : hip ratio (WHR) was a predictor for BMD at femoral neck.

CONCLUSIONS

These results suggest that BMD is influenced by dietary factors other than calcium and vitamin D. However, nondietary factors such as age, WHR, PTH, and body weight may be important determinants of BMD in postmenopausal women.

Fatty acid composition in matrix vesicles and in microvilli from femurs of chicken embryos revealed selective recruitment of fatty acids

Hypertrophic chondrocytes participate in matrix mineralization by releasing matrix vesicles (MVs). These MVs, by accumulating Ca(2+) and phosphate initiate the formation of hydroxyapatite. To determine the types of lipids essential for mineralization, we analyzed fatty acids (FAs) in MVs, microvilli and in membrane fractions of chondrocytes isolated from femurs of chicken embryos. The FA composition in the MVs was almost identical to that in microvilli, indicating that the MVs originated from microvilli. These fractions contained more monounsaturated FAs especially oleic acid than in membrane homogenates of chondrocytes. They were enriched in 5,8,11-eicosatrienoic acid (20:3n-9), in eicosadienoic acid (20:2n-6), and in arachidonic acid (20:4n-6). In contrast, membrane homogenates from chondrocytes were enriched in 20:1n-9, 18:3n-3, 22:5n-3 and 22:5n-6. Due to their relatively high content in MVs and to their selective recruitment within microvilli from where MV originate, we concluded that 20:2n-6 and 20:3n-9 (pooled values), 18:1n-9 and 20:4n-6 are essential for the biogenesis of MVs and for bone mineralization.

Exposure to omega-3 fatty acids at early age accelerate bone growth and improve bone quality

Omega-3 fatty acids (FAs) are essential nutritional components that must be obtained from foods. Increasing evidence validate that omega-3 FAs are beneficial for bone health, and several mechanisms have been suggested to mediate their effects on bone, including alterations in calcium absorption and urinary calcium loss, prostaglandin synthesis, lipid oxidation, osteoblast formation and inhibition of osteoclastogenesis. However, to date, there is scant information regarding the effect of omega-3 FAs on the developing skeleton during the rapid growth phase. In this study we aim to evaluate the effect of exposure to high levels of omega-3 FAs on bone development and quality during prenatal and early postnatal period. For this purpose, we used the fat-1 transgenic mice that have the ability to convert omega-6 to omega-3 fatty acids and the ATDC5 chondrogenic cell line as models. We show that exposure to high concentrations of omega-3 FAs at a young age accelerates bone growth through alterations of the growth plate, associated with increased chondrocyte proliferation and differentiation. We further propose that those effects are mediated by the receptors G-protein coupled receptor 120 (GPR120) and hepatic nuclear factor 4α, which are expressed by chondrocytes in culture. Additionally, using a combined study on the structural and mechanical bone parameters, we show that high omega-3 levels contribute to superior trabecular and cortical structure, as well as to stiffer bones and improved bone quality. Most interestingly, the fat-1 model allowed us to demonstrate the role of maternal high omega-3 concentration on bone growth during the gestation and postnatal period.

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.

High dietary arachidonic acid levels affect the process of eye migration and head shape in pseudoalbino Senegalese sole Solea senegalensis early juveniles

The effect of high dietary levels of arachidonic acid (ARA) on the eye migration and cranial bone remodelling processes in Senegalese sole Solea senegalensis early juveniles (age: 50 days post hatch) was evaluated by means of geometric morphometric analysis and alizarin red staining of cranial skeletal elements. The incidence of normally pigmented fish fed the control diet was 99·1 ± 0·3% (mean ± s.e.), whereas it was only 18·7 ± 7·5% for those fed high levels of ARA (ARA-H). The frequency of cranial deformities was significantly higher in fish fed ARA-H (95·1 ± 1·5%) than in those fed the control diet (1·9 ± 1·9%). Cranial deformities were significantly and negatively correlated with the incidence of normally pigmented animals (r² = -0·88, P < 0·001, n = 16). Thus, fish displaying pigmentary disorders differed in the position of their eyes with regard to the vertebral column and mouth axes, and by the interocular distance and head height, which were shorter than in fish not displaying pigmentary disorders. In addition to changes in the positioning of both eyes, pseudoalbino fish showed some ARA-induced osteological differences for some of the skeletal elements from the splanchnocranium (e.g. right premaxillary, dentary, angular, lacrimal, ceratohyal and branchiostegal rays) and neurocranium (e.g. sphenotic, left lateral ethmoid and left frontal) by comparison to normally pigmented specimens. Pseudoalbino fish also had teeth in both lower and upper jaws. This is the first study in Pleuronectiformes that describes impaired metamorphic relocation of the ocular side eye, the right eye in the case of S. senegalensis, whereas the left eye migrated into the ocular side almost normally.

The essentials of essential fatty acids

All fats, including saturated fatty acids, have important roles in the body. However, the most important fats are those that the body cannot make and thus must come from the food we eat. These essential fatty acids (EFAs) are based on linoleic acid (omega-6 group) and alpha-linolenic acid (omega-3 group). We need both groups of essential fatty acids to survive. For various reasons EFA deficiency is common in the general population, as is a disproportionate intake of omega-6 fatty acids over omega-3 fatty acids. As such, it is important to eat the right foods to make sure that you're taking in enough and the right kinds of the essential fatty acids. However, there is much more to the story. Studies have shown that increasing the intake of certain essential fatty acids, either alone or in combination with other fats and compounds, can increase health, help in treating certain diseases, and even improve body composition, mental and physical performance.

Causes, consequences, and treatment of osteoporosis in men

Men undergo gradual bone loss with aging, resulting in fragile bones. It is estimated that one in five men will suffer an osteoporotic fracture during their lifetime. The prognosis for men after a hip fracture is very grim. A major cause is reduction of free testosterone. Many other factors result in secondary osteoporosis, including treatment for other diseases such as cancer and diabetes. Patients should be screened not only for bone density but also assessed for their nutritional status, physical activity, and drug intake. Therapy should be chosen based on the type of osteoporosis. Available therapies include testosterone replacement, bisphosphonates, and nutritional supplementation with calcium, vitamin D, fatty acids, and isoflavones, as well as certain specific antibodies, like denosumab and odanacatib, and inhibitors of certain proteins.

Endogenous n-3 polyunsaturated fatty acids (PUFAs) mitigate ovariectomy-induced bone loss by attenuating bone marrow adipogenesis in FAT1 transgenic mice

Aim

To investigate the effect of endogenous n-3 polyunsaturated fatty acids (PUFAs) on bone marrow adipogenesis under osteoporosis conditions.

Methods

A mouse osteoporosis model overexpressing the FAT1 gene from Caenorhabditis elegans and converting n-6 PUFAs to n-3 PUFAs endogenously was used.

Results

The mice presented significantly lower bone marrow adiposity (adipocyte volume/tissue volume, mean adipocyte number) but increased the bone parameters (bone mineral density, bone mineral content, bone volume/total volume) in the distal femoral metaphysis.

Conclusion

Endogenous n-3 PUFAs protect bone marrow adipogenesis, which provides a novel drug target.

In situ fatty acid profile of femoral cancellous subchondral bone in osteoarthritic and fragility fracture females: implications for bone remodelling

We report here differences in the fatty acid profile of cancellous bone matrix, including n-3, n-6, mono- and poly-unsaturated, as well as saturated fats, between femoral heads from female OA (n=8, aged 68-88years), fractured neck of femur (#NOF) (n=19, 67-88years) and autopsy controls (CTRL) (n=4, 85-97years). Femoral heads were collected from individuals undergoing orthopaedic surgery for OA or #NOF; the fatty acid profile of sub-samples from the superior principal compressive and superior principal tensile regions were determined by gas chromatography. A total of 42 individual fatty acids were detected at varying concentrations with significant differences between subchondral bone from OA subjects, subchondral bone from #NOF subjects and subchondral bone from CTRL subjects, as well as between the superior principal compressive and superior principal tensile regions (for saturated fats only). Subchondral bone from OA subjects had higher total n-6 (OA=10.89±3.17, #NOF=11.11±1.83, CTRL=8.32±2.05, p=0.008) and total n-3 (OA=1.34±0.38, #NOF=1.19±0.18, CTRL=1.15±0.48, p=0.011) percentages than subchondral bone from #NOF subjects and subchondral bone from CTRL subjects, and there was no difference in the n-6:n-3 ratio, nor within the percentage of n-9 fatty acids. Arachidonic acid (OA=0.42±0.16, #NOF=0.26±0.06, CTRL=0.28±0.06, p=0.01), and γ-linolenic acid (OA=0.11±0.03, #NOF=0.05±0.02, CTRL=0.04±0.02, p<0.001) were higher in subchondral bone from OA subjects than subchondral bone from #NOF subjects and subchondral bone from CTRL subjects. In conclusion, there is a wide diversity of fatty acids in cancellous bone matrix from the femoral heads of OA and #NOF, suggesting they may have regulatory effects on inflammatory processes, and their metabolites. This article is part of a Special Issue entitled "Osteoarthritis".

Perinatal maternal dietary supplementation of ω3-fatty acids transiently affects bone marrow microenvironment, osteoblast and osteoclast formation, and bone mass in male offspring

It is increasingly evident that micronutrient environment experienced before birth and in infancy is important for achieving optimal bone mass by adolescence and maintaining bone health. This study determined whether maternal supplementation with ω3-polyunsaturated fatty acids (n3FA) improved offspring bone growth and adult bone mass. Female rats were fed a diet containing 0.1% (control, n = 10) or 1% (n3FA, n = 11) docosahexanoic acid (DHA) during pregnancy and lactation. Offspring were weaned onto a control rat chow diet. Tibial growth plate and metaphysis structure, osteoblast/osteoclast density and differentiation, and gene expression were assessed in offspring at 3 wk (weaning), 6 wk (adolescent), and 3 months (adult). Maternal n3FA supplementation elevated offspring plasma n3FA levels at 3 and 6 wk. Although total growth plate heights were unaffected at any age, the resting zone thickness was increased in both male and female offspring at 3 wk. In n3FA males, but not females, bone trabecular number and thickness were increased at 3 wk but not other ages. The wk 3 n3FA males also exhibited an increased bone volume, an increased osteoblast but decreased osteoclast density, and lower expression of osteoclastogenic cytokines receptor activator of nuclear factor-κB ligand, TNF-α, and IL-6. No effects were seen at 6 wk or 3 months in either sex. Thus, perinatal n3FA supplementation is associated with increased bone formation, decreased resorption, and a higher bone mass in males, but not in females, at weaning; these effects do not persist into adolescence and adulthood and are unlikely to produce lasting improvements in bone health.

Plasma phosphatidylcholine concentrations of polyunsaturated fatty acids are differentially associated with hip bone mineral density and hip fracture in older adults: the Framingham Osteoporosis Study

Polyunsaturated fatty acids (PUFAs) may influence bone health. The objective of this work was to examine associations between plasma phosphatidylcholine (PC) PUFA concentrations and hip measures: (1) femoral neck bone mineral density (FN-BMD) (n = 765); (2) 4-year change in FN-BMD (n = 556); and (3) hip fracture risk (n = 765) over 17-year follow-up among older adults in the Framingham Osteoporosis Study. BMD measures were regressed on quintile of plasma PC PUFAs (docosahexaenoic acid [DHA], linoleic acid [LA], and arachidonic acid [AA]), adjusted for covariates. Hazard ratios (HR) and 95% confidence interval (CI) for hip fracture were estimated by quintile of plasma PC PUFAs, adjusted for covariates. Higher concentrations of PC DHA were associated with loss of FN-BMD over 4 years in women (p-trend = 0.04), but was protective in men in the uppermost quintile compared to men grouped in the lower four quintiles, in post hoc analysis (p = 0.01). PC LA concentrations were inversely associated with baseline FN-BMD in women (p-trend = 0.02), and increased hip fracture risk in women and men (p-trend = 0.05), but body mass index (BMI) adjustment attenuated these associations (p-trend = 0.12 and p-trend = 0.14, respectively). A trend toward a protective association was observed between PC AA and baseline FN-BMD in men (p-trend = 0.06). Women and men with the highest PC AA concentrations had 51% lower hip fracture risk than those with the lowest (HR = 0.49, 95% CI = 0.24-1.00). Opposing effects of PC DHA on FN-BMD loss observed in women and men need further clarification. Bone loss associated with PC LA may be confounded by BMI. High PC AA concentrations may be associated with reduced hip fracture risk.

[High-fat diets and body composition over two generations. An experimental study]

INTRODUCTION AND OBJECTIVE

Despite recent findings reported on the nutritional factors that induce epigenetic changes, little information is available at early ages. This study analyzed in an experimental model, over two generations, potential changes in body composition and potential expression of epigenetic changes as the result of the intake of isoenergetic diets with different fat levels.

MATERIALS AND METHODS

At weaning, Wistar female rats were divided into two groups that were fed either a control diet (fat=7% w/w) or a high-fat diet (15% w/w). Rats were mated at 70 days (M(1)) and their pups (P(1)) were the first generation; P(1) rats were mated at 70 days (M(2)) and their pups (P(2)) represented the second generation. At weaning, mothers and pups (M(1), M(2) and P(1), P(2)) were measured body weight (W) and composition (% body fat, %BF), and total skeleton bone mineral content (BMC), expressed as %BMC, using chemical and DXA methods respectively.

RESULTS

At weaning, high-fat diet groups M(2) and P(2) showed significant increases in W and %BF (p<0.05); increased %BF values were already found in the M(1) and P(1) groups (p<0.001). By contrast, %BMC significantly decreased in M(2) and P(2) rats (p<0.001).

CONCLUSION

This study demonstrates the need to review certain eating habits to avoid perpetuation of unhealthy patterns generation after generation.

Alternative therapies for the prevention and treatment of osteoporosis

Osteoporosis is a medical condition that affects millions of men and women. People with this condition have low bone mass, which places them at increased risk for bone fracture after minor trauma. The surgeries and treatments required to repair and heal bone fractures involve long recovery periods and can be expensive. Because osteoporosis occurs frequently in the elderly, the financial burden it places on society is likely to be large. In the United States, the Food and Drug Administration has approved several drugs for use in the prevention and treatment of osteoporosis. However, all of the currently available agents have severe side effects that limit their efficacy and underscore the urgent need for new treatment options. One promising approach is the development of alternative (nonpharmaceutical) strategies for bone maintenance, as well as for the prevention and treatment of osteoporosis. This review examines the currently available nonpharmaceutical alternatives that have been evaluated in in vitro and in vivo studies. Certain plants from the following families have shown the greatest benefits on bone: Alliceae, Asteraceae, Thecaceae, Fabaceae, Oleaceae, Rosaceae, Ranunculaceae, Vitaceae, Zingiberaceae. The present review discusses the most promising findings from studies of these plant families.

Do ω-3 or other fatty acids influence the development of 'growing pains'? A prebirth cohort study

OBJECTIVES

To assess whether the prevalence of growing pains varies with indicators of fatty acid exposure. Growing pains (limb pains of no obvious explanation) have been shown to be strongly linked to a family history of arthritis, and are thought to predict an increased risk of the development of arthritis in adulthood. Much has been made of the possibility of fatty acids, particularly the ω-3 fatty acids, playing a preventive role in the development of arthritis, but little research has been undertaken to determine whether such fatty acids might reduce the risk of growing pains. We aimed to assess whether the prevalence of growing pains varies with indicators of fatty acid exposures.

DESIGN

Case-control study nested within a prospective longitudinal cohort comparing prenatal and postnatal diet, blood measures and variants in fatty acid desaturase (FADS) genes that influence the metabolism of fatty acids. Statistical analysis took account of factors such as gender, smoke exposure, maternal age and education, social class and parity.

SETTING

Avon Longitudinal Study of Parents & Children.

PARTICIPANTS

All children born between 1 April 1991 and 31 December 1992 (approximately14 000) within the Avon area (only that part of Avon under the South-West Regional Health Authority). This project compared 1676 children who reported 'growing pains' at age 8 with 6155 with no such pain.

PRIMARY OUTCOME

Reported limb pains of no apparent origin.

RESULTS

There was no indication that the affected children had diets that differed with regard to ω-3, plasma levels of fatty acids, or the FADS genetic variants. We also assessed fetal and infant exposure but neither maternal prenatal blood levels nor maternal dietary intake, or duration of breast feeding showed any significant relationships even after adjustment for confounders.

CONCLUSIONS

Thus, there is no evidence that ω-3 fatty acid status protects against the development of growing pains in childhood.

Absence of glutamine supplementation prevents differentiation of murine calvarial osteoblasts to a mineralizing phenotype

Osteoblasts in vitro differentiate from a proliferating to a mineralizing phenotype upon transfer to a medium rich in beta-glycerophosphate and ascorbic acid. The nutritional requirements of the cells at different stages of this differentiation process are not known. In other cell types, nutritional supplementation during surgery can improve the outcome in terms of speed of patient recovery and prognosis. There is therefore the potential for supplementation at the site of fracture repair or bone grafting with critical osteoblast nutritional factors to potentially accelerate healing. In this study we investigate which common cell nutrients are required for the proliferating and mineralizing stages of osteoblast differentiation. Medium containing 5.5 mM glucose was sufficient to achieve maximal proliferation of primary calvarial osteoblasts and human osteoblast cell lines, with some added benefit of additional glutamine supplementation. However, when cells were stimulated to mineralize, glucose was insufficient to support their energetic requirements. Only when cells were supplemented with glucose together with glutamine were high levels of osteocalcin expression observed together with mineralized nodules in culture, suggesting that this would be a useful combination to assess in cultures of primary human osteoblasts to determine whether it may have beneficial effects during fracture surgery, bone grafting, and fixation of uncemented arthroplasty implants.

Regulation of osteoarthritis by omega-3 (n-3) polyunsaturated fatty acids in a naturally occurring model of disease

OBJECTIVE

To examine effects of high omega-3 (n-3) polyunsaturated fatty acid (PUFA) diets on development of osteoarthritis (OA) in a spontaneous guinea pig model, and to further characterise pathogenesis in this model. Modern diets low in n-3 PUFAs have been linked with increases in inflammatory disorders, possibly including OA. However, n-3 is also thought to increases bone density, which is a possible contributing factor in OA. Therefore we aim to determine the net influence of n-3 in disease development.

METHOD

OA-prone Dunkin-Hartley (DH) Guinea pigs were compared with OA-resistant Bristol Strain-2s (BS2) each fed a standard or an n-3 diet from 10 to 30 weeks (10/group). We examined cartilage and subchondral bone pathology by histology, and biochemistry, including collagen cross-links, matrix metalloproteinases (MMPs), alkaline phosphatase, glycosaminoglycan (GAG), and denatured type II collagen.

RESULTS

Dietary n-3 reduced disease in OA-prone animals. Most cartilage parameters were modified by n-3 diet towards those seen in the non-pathological BS2 strain - significantly active MMP-2, lysyl-pyridinoline and total collagen cross-links - the only exception being pro MMP-9 which was lower in the BS2, yet increased with n-3. GAG content was higher and denatured type II lower in the n-3 group. Subchondral bone parameters in the DH n-3 group also changed towards those seen in the non-pathological strain, significantly calcium:phosphate ratios and epiphyseal bone density.

CONCLUSION

Dietary n-3 PUFA reduced OA in the prone strain, and most disease markers were modified towards those of the non-OA strain, though not all significantly so. Omega-3 did not increase markers of pathology in either strain.

High-fat diets affect energy and bone metabolism in growing rats

BACKGROUND

High-fat diets are usually associated with greater weight (W) gain and body fat (BF). However, it is still unclear whether the type and amount of fat consumed influence BF. Additionally, dietary fat intake may also have consequences on skeletal health.

OBJECTIVE

To evaluate in healthy growing rats the effects of high-fat diets and type of dietary fat intake (saturated or vegetable oils) on energy and bone metabolism.

METHODS

At weaning, male Wistar rats (n = 50) were fed either a control diet (C; fat = 7% w/w) or a high-fat diet (20% w/w) containing either: soybean oil, corn oil (CO), linseed oil (LO), or beef tallow (BT) for 8 weeks. Zoometric parameters, BF, food intake and digestibility, and total and bone alkaline phosphatase (b-AP) were assessed. Total skeleton bone mineral density (BMD) and content (BMC), BMC/W, spine BMD, and bone volume (static-histomorphometry) were measured.

RESULTS

Animals fed BT diet achieved lower W versus C. Rats fed high-fat vegetable oil diets showed similar effects on the zoometric parameters but differed in BF. BT showed the lowest lipid digestibility and BMC. In contrast, high vegetable oil diets produced no significant differences in BMC, BMC/W, BMD, spine BMD, and bone volume. Marked differences were observed for LO and BT groups in b-AP and CO and BT groups in bone volume.

CONCLUSION

BT diet rich in saturated fatty acids had decreased digestibility and adversely affected energy and bone metabolisms, in growing healthy male rats. There were no changes in zoometric and bone parameters among rats fed high vegetable oil diets.

Combined effects of soy isoflavone and fish oil on ovariectomy-induced bone loss in mice

Both soy isoflavone and n-3 polyunsaturated fatty acids are known to reduce the levels of bone-resorbing cytokines; however, the synergistic effects of these food ingredients have not been examined yet. This study was performed to elucidate the effect of concomitant intake of soy isoflavone and fish oil on bone mass in ovariectomized mice. Eight-week-old ddY female mice were subjected to ovariectomy (OVX) or sham surgery, and then fed an AIN-93G with safflower oil (So) as a control lipid source, isoflavone-supplemented safflower oil (So + I), fish oil instead of safflower oil (Fo) or isoflavone-supplemented fish oil (Fo + I) for 4 weeks. Femoral bone mineral density was significantly decreased by OVX; however, this decrease was inhibited by the intake of isoflavone and/or fish oil. Histomorphometric analyses showed that bone volume and trabecular thickness in the distal femoral trabecular bone were significantly lower in the So group than in the sham group, but those were restored in the Fo + I groups. The number of osteoclasts was significantly decreased by isoflavone intake. The increased rate of bone resorption after OVX was inhibited by isoflavone and/or fish oil. The serum concentration of tumor necrosis factor alpha was increased after OVX, but was significantly lower with the combination of isoflavone with fish oil than isoflavone or fish oil alone. The results of this study indicated that the intakes of soy isoflavone and/or fish oil might have ameliorating effects on bone loss due to OVX. Further, the concomitant intake of soy isoflavone and fish oil at a low dose showed better effects on cytokines related with bone resorption.

Avaliação da carcaça de cabritos Saanen alimentados com dietas com grãos de oleaginosas

Foram utilizados 16 cabritos Saanen não castrados dos 15,16±1,60kg até 30,61±0,33kg de peso vivo, distribuídos em delineamento inteiramente ao acaso, alimentados com dietas (tratamentos) com grãos de linhaça, girassol ou canola. A dieta-controle foi formulada com feno de aveia, farelo de soja, milho moído e suplemento vitamínico-mineral. Os pesos da carcaça quente e fria e os rendimentos da carcaça e de cortes comerciais não foram modificados pelos tratamentos. A dieta com grãos de canola resultou em maior perda por resfriamento da carcaça e menor proporção de gordura no lombo, e a proporção de osso no lombo foi maior para os animais que receberam linhaça ou canola. Os teores de umidade, proteína, lipídios totais e cinzas do músculo Longissimus dorsi não foram alterados com a adição dos grãos de oleaginosas. A dieta com grãos de linhaça resultou em aumento do teor de ômega-3 no músculo, e o teor de colesterol e a razão ômega-6/ômega-3 foram menores nos tratamentos que continham linhaça, girassol e canola. A inclusão dos grãos de oleaginosas nas dietas não alterou as características quantitativas da carcaça de cabritos Saanen, mas melhorou a qualidade da carne, que apresentou menos colesterol e mais ômega-3, com o uso de linhaça.

Lifestyle modifications and the resolution of obstructive sleep apnea syndrome: a case report

OBJECTIVE

This purpose of this case study is to describe a natural method to help in management of obstructive sleep apnea syndrome (OSAS), which is known to be a common and debilitating condition.

CLINICAL FEATURES

Obstructive sleep apnea syndrome is typically managed with a continuous positive airway pressure (CPAP) device, which the patient wears during sleep to help maintain respiration. This report describes the chiropractic management and resolution of OSAS with dietary modifications in a 55-year-old man who wore a CPAP for 10 years.

INTERVENTION AND OUTCOME

After adhering to dietary modifications for 3 months, the patient no longer required the use of the CPAP device and continues to have a normal active lifestyle almost 7 years later.

CONCLUSION

Dietary modifications may be an effective tool to improve the management of OSAS.

The effect of polyunsaturated fatty acids on bone health

The essential polyunsaturated fatty acids (PUFAs) are divided into two classes, n-3 (ω-3) and n-6 (ω-6) and their dietary precursors are α-linolenic (ALA) and linoleic acid (LA), respectively. PUFAs are precursors of a wide range of metabolites, for example eicosanoids like prostaglandins and leukotrienes, which play critical roles in the regulation of a variety of biological processes, including bone metabolism.

A large body of evidence supports an effect of PUFA on bone metabolism which may be mediated by regulation of osteoblastogenesis and osteoclast activity, change of membrane function, decrease in inflammatory cytokines, such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumour necrosis factor alpha (TNF-α), modulation of peroxisome proliferators-activated receptor γ (PPARγ) and influence in NO secretion and NO synthase.

Animal studies have shown that a higher dietary omega-3/omega-6 fatty acids ratio is associated with beneficial effects on bone health. Human studies conducted in elderly subjects suggest that omega-3 instead of omega-6 has a positive effect on bone metabolism. In spite of increasing evidence, studies conducted in humans do not allow us to draw a definitive conclusion on the usefulness of PUFAs in clinical practice.

Endogenously produced n-3 fatty acids protect against ovariectomy induced bone loss in fat-1 transgenic mice

Aging is associated with bone loss, leading to increased risk of fractures. Recently, there is growing interest in identifying nutritional supplements that can prevent bone loss with minimum side effects. There is increasing evidence for the beneficial effects of n-3 fatty acids in the prevention of bone loss. A transgenic mouse model (fat-1) that produces n-3 fatty acids endogenously and its wild type counterpart were used in this study to determine the effects of endogenously produced n-3 fatty acids on serum bone turnover markers, long bones, and lumbar vertebrae. Serum alkaline phosphatase and P1NP levels decreased significantly in wild type mice after ovariectomy. No significant changes were seen in osteocalcin. Cancellous and cortical bone mass were higher in the femur of fat-1 mice. In wild type mice, there was significant loss of bone after ovariectomy in the distal femur, femoral neck, proximal tibia, and fourth lumbar vertebra. However, in fat-1 mice, there was no, or significantly less, bone lost after ovariectomy in all the sites studied. We conclude that endogenously produced n-3 fatty acids can attenuate ovariectomy induced bone loss in the different bone sites studied, mainly as a consequence of decreased bone resorption at the endosteal surface.

Effects of long-term supplementation with omega-3 fatty acids on longitudinal changes in bone mass and microstructure in mice

A diet rich in omega-3s has previously been suggested to prevent bone loss. However, evidence for this has been limited by short exposure to omega-3 fatty acids (FAs). We investigated whether a diet enriched in eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) for the entire adult life of mice could improve bone microstructure and strength. Thirty female mice received a diet enriched in DHA or EPA or an isocaloric control diet from 3 to 17 months of age. Changes in bone microstructure were analyzed longitudinally and biomechanical properties were analysed by a three-point bending test. Bone remodelling was evaluated by markers of bone turnover and histomorphometry. Trabecular bone volume in caudal vertebrae was improved by EPA or DHA at 8 months (+26.6% and +17.2%, respectively, compared to +3.8% in controls, P=.01), but not thereafter. Trabecular bone loss in the tibia was not prevented by omega-3 FAs (BV/TV -94%, -93% and -97% in EPA, DHA and controls, respectively). EPA improved femur cortical bone volume (+8.1%, P<.05) and thickness (+4.4%, P<.05) compared to controls. EPA, but not DHA, reduced age-related decline of osteocalcin (-70% vs. -83% in controls, P<.05). EPA and DHA increased leptin levels (7.3±0.7 and 8.5±0.5 ng ml⁻¹, respectively, compared to 4.5±0.9 ng ml⁻¹ in controls, P=.001); however, only EPA further increased IGF-1 levels (739±108 ng ml⁻¹, compared to 417±58 ng ml⁻¹ in controls, P=.04). These data suggest that long-term intake of omega-3 FA, particularly EPA, may modestly improve the structural and mechanical properties of cortical bone by an increase in leptin and IGF-1 levels, without affecting trabecular bone loss.

Diet and hip fractures among elderly Europeans in the EPIC cohort

BACKGROUND/OBJECTIVES

Evidence on the role of diet during adulthood and beyond on fracture occurrence is limited. We investigated diet and hip fracture incidence in a population of elderly Europeans, participants in the European Prospective Investigation into Cancer and nutrition study.

SUBJECTS/METHODS

29, 122 volunteers (10,538 men, 18,584 women) aged 60 years and above (mean age: 64.3) from five countries were followed up for a median of 8 years and 275 incident hip fractures (222 women and 53 men) were recorded. Diet was assessed at baseline through validated dietary questionnaires. Data were analyzed through Cox proportional-hazards regression with adjustment for potential confounders.

RESULTS

No food group or nutrient was significantly associated with hip fracture occurrence. There were suggestive inverse associations, however, with vegetable consumption (hazard ratio (HR) per increasing sex-specific quintile: 0.93, 95% confidence interval (CI): 0.85-1.01), fish consumption (HR per increasing sex-specific quintile: 0.93, 95% CI: 0.85-1.02) and polyunsaturated lipid intake (HR per increasing sex-specific quintile: 0.92, 95% CI: 0.82-1.02), whereas saturated lipid intake was positively associated with hip fracture risk (HR per increasing sex-specific quintile: 1.13, 95% CI: 0.99-1.29). Consumption of dairy products did not appear to influence the risk (HR per increasing sex-specific quintile: 1.02, 95% CI: 0.93-1.12).

CONCLUSIONS

In a prospective study of the elderly, diet, including consumption of dairy products, alcohol and vitamin D, did not appear to play a major role in hip fracture incidence. There is however, weak and statistically non-significant evidence that vegetable and fish consumption and intake of polyunsaturated lipids may have a beneficial, whereas saturated lipid intake a detrimental effect.

A study of bone marrow and subcutaneous fatty acid composition in subjects of varying bone mineral density

Osteoporosis is associated with an increase in marrow fat. Fats, particularly polyunsaturated fats, either in co-cultures or diet, have been shown to significantly influence bone remodeling. Whether the increase in marrow fat seen in osteoporosis is also associated with a change in fatty acid composition is not known. This study was undertaken to investigate the fatty acid composition in subjects of varying bone mineral density (BMD). Samples of marrow fat and subcutaneous fat from 126 subjects (98 females, 34 males, mean age 69.7+/-10.5 years) undergoing orthopedic surgery were analyzed for fatty acid composition by gas chromatography. These results were correlated with BMD assessed by DXA. A total of 22 fatty acids were identified in marrow and subcutaneous fat. Significant differences in fatty acid composition existed between marrow and subcutaneous fat as well as between marrow fat samples obtained from the proximal femur and proximal tibia. Other than cis-7-hexadecenoic acid [C16:1 (n=9)] and docosanoic acid [C22:0], no difference in marrow fatty acid composition was evident between subject groups of varying BMD (normal, low bone mass, and osteoporosis). In conclusion, there exists a wide range of individual fatty acids in marrow fat. Marrow fatty acid composition differs from that of subcutaneous fat and varies between predominantly erythropoetic and fatty marrow sites. Other than cis-7-hexadecenoic acid [C16:1 (n=9)] and docosanoic acid [C22:0], no difference in marrow fatty acid composition was evident between subjects of varying BMD.

Conjugated linoleic acid prevents growth attenuation induced by corticosteroid administration and increases bone mineral content in young rats

Corticosteroids are a common therapy in many disease states, despite frequent and potentially serious side effects. Nutritional supplementation with conjugated linoleic acid (CLA) has been shown to increase fat-free mass, whereas supplementation with n-3 and n-6 fatty acids has been shown to increase bone mineral density (BMD). To determine whether CLA can attenuate the side effects of 8 weeks of corticosteroid administration, we randomized twenty-four 5-week-old male Sprague-Dawley rats into 1 of 4 groups: control; control + methylprednisolone (7 mg.kg-1.week-1); CLA diet (1% CLA w/w); or CLA plus methylprednisolone. Body composition, bone mineral content (BMC), and BMD were assessed with dual-energy X-ray absorptiometry at the onset and at the end of the 8-week intervention. The mechanical properties of bone were determined using 3-point femur bending at the end of the intervention. Methylprednisolone resulted in an attenuation of the increase in body mass and lean mass over the 8 weeks (p < 0.05). CLA prevented the methylprednisolone-induced attenuation of body mass and lean mass accumulation. CLA also resulted in a greater increase in BMC (p < 0.05) in the lumbar spine. The energy at failure of the isolated femurs was increased with CLA (p < 0.05). Dietary CLA prevents many of the growth- and bone-related side effects arising from 8 weeks of corticosteroid administration, results in greater increases in BMC and BMD, and can contribute to an improvement in some of the mechanical properties of bone.