Category Archives: Supplements

Fish or Fish Oil No Association With Fracture – 2010

Abstract

Fish consumption, bone mineral density, and risk of hip fracture among older adults: the cardiovascular health study.

Marine n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may be beneficial for bone health, but few studies have investigated the association with fish consumption. Our aim was to study associations of fish and EPA + DHA consumption with bone mineral density (BMD) and hip fracture risk and determine whether high linoleic acid (LA) intake, the major dietary n-6 PUFA, modifies the associations. The study population consisted of 5045 participants aged 65 years and older from the Cardiovascular Health Study. Data on BMD were available for 1305 participants. Food-frequency questionnaire was used to assess dietary intake, and hip fracture incidence was assessed prospectively by review of hospitalization records. After multivariable adjustment, femoral neck BMD was 0.01 g/cm(2) lower in the highest versus lowest tuna/other-fish intake category (p = .05 for trend). EPA + DHA intake (higher versus lower median of 0.32 g/day) was associated with lower femoral neck BMD (0.66 versus 0.71 g/cm(2), p < .001) among those with LA intake greater than the median 12.1 g/day (p = .03 for interaction). No significant associations were found with total-hip BMD. During mean follow-up of 11.1 years, 505 hip fractures occurred. Fish or EPA + DHA consumption was not significantly associated with fracture incidence [hazard ratio (HR) for extreme categories: HR = 1.23, 95% confidence interval (CI) 0.83-1.84 for tuna/other fish; HR = 1.16, 95% CI 0.91-1.49 for fried fish; and HR = 0.98, 95% CI 0.71-1.36 for EPA + DHA]. High LA intake did not modify these associations. In this large prospective cohort of older adults, fish consumption was associated with very small differences in BMD and had no association with hip fracture risk.

Virtanen JK, Mozaffarian D, Cauley JA, Mukamal KJ…
J. Bone Miner. Res. Sep 2010
PMID: 20572022 | Free Full Text

Protein + Calcium Protects Against Fractures in the Framingham Study – 2010

Abstract

Protective effect of high protein and calcium intake on the risk of hip fracture in the Framingham offspring cohort.

The effect of protein on bone is controversial, and calcium intake may modify protein’s effect on bone. We evaluated associations of energy-adjusted tertiles of protein intake (ie, total, animal, plant, animal/plant ratio) with incident hip fracture and whether total calcium intake modified these associations in the Framingham Offspring Study. A total of 1752 men and 1972 women completed a baseline food frequency questionnaire (1991-1995 or 1995-1998) and were followed for hip fracture until 2005. Hazard ratios (HRs) were estimated using Cox proportional hazards regression adjusting for confounders. Baseline mean age was 55 years (SD 9.9 years, range 26 to 86 years). Forty-four hip fractures occurred over 12 years of follow-up. Owing to significant interaction between protein (total, animal, animal/plant ratio) and calcium intake (p interaction range = .03 to .04), stratified results are presented. Among those with calcium intakes less than 800 mg/day, the highest tertile (T3) of animal protein intake had 2.8 times the risk of hip fracture [HR = 2.84, 95% confidence interval (CI) 1.20-6.74, p = .02] versus the lowest tertile (T1, p trend = .02). In the 800 mg/day or more group, T3 of animal protein had an 85% reduced hip fracture risk (HR = 0.15, 95% CI 0.02-0.92, p = .04) versus T1 (p trend = .04). Total protein intake and the animal/plant ratio were not significantly associated with hip fracture (p range = .12 to .65). Our results from middle-aged men and women show that higher animal protein intake coupled with calcium intake of 800 mg/day or more may protect against hip fracture, whereas the effect appears reversed for those with lower calcium intake. Calcium intake modifies the association of protein intake and the risk of hip fracture in this cohort and may explain the lack of concordance seen in previous studies.

Sahni S, Cupples LA, McLean RR, Tucker KL…
J. Bone Miner. Res. Dec 2010
PMID: 20662074 | Free Full Text

Fish May Protect Bone in Older Adults – 2011

Abstract

Protective effects of fish intake and interactive effects of long-chain polyunsaturated fatty acid intakes on hip bone mineral density in older adults: the Framingham Osteoporosis Study.

Polyunsaturated fatty acids and fish may influence bone health.
We aimed to examine associations between dietary polyunsaturated fatty acid and fish intakes and hip bone mineral density (BMD) at baseline (1988-1989; n = 854) and changes 4 y later in adults (n = 623) with a mean age of 75 y in the Framingham Osteoporosis Study.

BMD measures were regressed on energy-adjusted quartiles of fatty acid intakes [n-3 (omega-3): α-linolenic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and EPA+ DHA; n-6 (omega-6): linoleic acid (LA) and arachidonic acid (AA); and n-6:n-3 ratio] and on categorized fish intakes, with adjustment for covariates. Effect modification by EPA+DHA intake was tested for n-6 exposures.
High intakes (≥3 servings/wk) of fish relative to lower intakes were associated with maintenance of femoral neck BMD (FN-BMD) in men (dark fish + tuna, dark fish, and tuna) and in women (dark fish) (P < 0.05). Significant interactions between AA and EPA+DHA intakes were observed cross-sectionally in women and longitudinally in men. In women with EPA+DHA intakes at or above the median, those with the highest AA intakes had a higher mean baseline FN-BMD than did those with the lowest intakes (quartile 4 compared with quartile 1: P = 0.03, P for trend = 0.02). In men with the lowest EPA+DHA intakes (quartile 1), those with the highest intakes of AA (quartile 4) lost more FN-BMD than did men with the lowest intakes of AA (quartile 1; P = 0.04). LA intake tended to be associated with FN-BMD loss in women (P for trend < 0.06).
Fish consumption may protect against bone loss. The protective effects of a high AA intake may be dependent on the amount of EPA+DHA intake.

Farina EK, Kiel DP, Roubenoff R, Schaefer EJ…
Am. J. Clin. Nutr. May 2011
PMID: 21367955 | Free Full Text

Fish Consumption Helps Maintain Bone in Spanish Women – 2013

Abstract

Dietary habits, nutrients and bone mass in Spanish premenopausal women: the contribution of fish to better bone health.

The moderate consumption of fish is recommended for a healthy diet and is also a feature of the Mediterranean diet. Fish is a major food group in diets throughout the world, and studies show that fish consumption is associated with a lower risk of a number of conditions. Spain has one of the highest annual per capita consumptions of fish worldwide. As fish is a source of high quality protein; n-3 polyunsaturated fatty acids; vitamins, such as A and D; and minerals, such as selenium, calcium, iodine, magnesium, copper and zinc, nutrients that have positive effects on bone characteristics, it has been proposed that its consumption could improve bone health. In this cross-sectional study, we have investigated the relationship between dietary habits and nutrient intake of 151 Spanish premenopausal women and analyzed the association of fish consumption on bone mass measured by quantitative ultrasound of the phalanges. A higher (P < 0.05) bone mass and vitamin D intake (P < 0.05) was observed in the group with a fish intake of 5-7 servings/week. We conclude that increased fish consumption is helpful in maintaining an adequate bone mass in Spanish premenopausal women.

Calderon-Garcia JF, Moran JM, Roncero-Martin R, Rey-Sanchez P…
Nutrients Jan 2013
PMID: 23271510 | Free Full Text

Review: Protein, Calcium, Vitamins D, C, K, and Fruits and Veggies in Osteoporosis

Abstract

The role of diet in osteoporosis prevention and management.

Diet, a modifiable osteoporosis risk factor, plays an important role in the acquisition and maintenance of bone mass. The influence of diet on bone begins in childhood; even maternal diet can influence bone mass in the offspring. A good general nutritional status and adequate dietary protein, calcium, vitamin D, fruits, and vegetables have a positive influence on bone health, while a high caloric diet and heavy alcohol consumption have been associated with lower bone mass and higher rates of fracture. The evidence for a role of other minerals and vitamins in skeletal health is not as strong, but recent evidence suggests that vitamins C and K might also have an effect on bone.

Levis S, Lagari VS
Curr Osteoporos Rep Dec 2012
PMID: 23001895

Low Protein Increases Bone Loss in Vitamin D Deficiency or Ovariectomy in Rats

Abstract

Low protein intake magnifies detrimental effects of ovariectomy and vitamin D on bone.

Protein-induced changes in bone and calcium homeostasis could potentially be greater in the elderly and in women at risk for osteoporosis. We hypothesize that a low protein intake would magnify the negative changes in bone metabolism seen in vitamin D (vitD) insufficiency and/or estrogen deficiency. The present study was undertaken to better understand how a low protein diet along with vitD insufficiency could affect bone metabolism using a rodent ovariectomized (OVX) model. Rats (n = 60) underwent ovariectomy (OVX) or sham operation. The first 15 days after surgery, all rats were fed a standard rodent diet. Thereafter, rats (n = 10/group) were fed a low protein diet (LP; 2.5 %) or a control diet (NP; 12.5 %) with 100 IU% vitD (+D; cholecalciferol) or without vitD (-D) for 45 days. The groups were as follows: SHAM + NP + D (control); SHAM + LP + D; SHAM + LP – D; OVX + NP + D; OVX + LP + D; OVX + LP – D. Body weight (BW) of control and OVX + NP + D groups increased while those feeding the LP diet, independently of vitD feedings, decreased (p < 0.05). The OVX + LP – D group presented the lowest serum Ca, phosphorus and osteocalcin levels and the highest CTX levels (p < 0.05). At the end of the study, total skeleton bone mineral content, proximal tibia bone mineral density, bone volume and trabecular number levels decreased as follows: SHAM + NP + D (controls) > SHAM + LP + D > OVX + NP + D > SHAM + LP – D > OVX + LP + D > OVX + LP – D (p < 0.05). A low protein diet negatively affected bone mass and magnified the detrimental effects of vitD and/or estrogen deficiencies.

Marotte C, Gonzales Chaves MM, Pellegrini GG, Friedman SM…
Calcif. Tissue Int. Aug 2013
PMID: 23708885

Review: Protein + Calcium May Benefit Bones – April 2011

Abstract

Dietary protein and bone health: harmonizing conflicting theories.

A precise understanding of the role of dietary protein in bone health has been evasive despite decades of research. It is known that a dietary acid load is harmful to bone, and sulfur-containing amino acids are metabolized to provide such an acid load. It is also known that protein elevates urine calcium loss. However, recent clinical studies and a meta-analysis have indicated either no effect or a modest benefit associated with higher protein intakes. These contradictory considerations may be explained by the existence of a two-faced relationship between protein and bone, with simultaneous positive and negative pathways. In opposition to the negative effects of dietary acid load, protein may exert positive effects related to improving calcium absorption, increasing insulin-like growth factor 1, or improving lean body mass, which, in turn, improves bone strength. Putative mechanisms behind these pathways are reviewed here, and some limitations in the historical literature as well as suggested measures to counter these in the future are identified. When positive and negative pathways are considered in tandem, protein may offer modest benefits to bone in the presence of adequate dietary calcium and acid-neutralizing fruits and vegetables.

Thorpe MP, Evans EM
Nutr. Rev. Apr 2011
PMID: 21457266

Review: Protein Recommended Intake – 2008

Abstract

Amount and type of protein influences bone health.

Many factors influence bone mass. Protein has been identified as being both detrimental and beneficial to bone health, depending on a variety of factors, including the level of protein in the diet, the protein source, calcium intake, weight loss, and the acid/base balance of the diet. This review aims to briefly describe these factors and their relation to bone health. Loss of bone mass (osteopenia) and loss of muscle mass (sarcopenia) that occur with age are closely related. Factors that affect muscle anabolism, including protein intake, also affect bone mass. Changes in bone mass, muscle mass, and strength track together over the life span. Bone health is a multifactorial musculoskeletal issue. Calcium and protein intake interact constructively to affect bone health. Intakes of both calcium and protein must be adequate to fully realize the benefit of each nutrient on bone. Optimal protein intake for bone health is likely higher than current recommended intakes, particularly in the elderly. Concerns about dietary protein increasing urinary calcium appear to be offset by increases in absorption. Likewise, concerns about the impact of protein on acid production appear to be minor compared with the alkalinizing effects of fruits and vegetables. Perhaps more concern should be focused on increasing fruit and vegetable intake rather than reducing protein sources. The issue for public health professionals is whether recommended protein intakes should be increased, given the prevalence of osteoporosis and sarcopenia.

Heaney RP, Layman DK
Am. J. Clin. Nutr. May 2008
PMID: 18469289 | Free Full Text

Protein Increases Calcium Absorption and Retention From a Low-Calcium Diet – 2009

Abstract

Dietary protein and calcium interact to influence calcium retention: a controlled feeding study.

The effect of meat protein on calcium retention at different calcium intakes is unresolved. The objective was to test the effect of dietary protein on calcium retention at low and high intakes of calcium.In a randomized controlled feeding study with a 2 x 2 factorial crossover design, healthy postmenopausal women (n = 27) consumed either approximately 675 or approximately 1510 mg Ca/d, with both low and high protein (providing 10% and 20% energy) for 7 wk each, separated by a 3-wk washout period. After 3 wk, the entire diet was extrinsically labeled with (47)Ca, and isotope retention was monitored by whole-body scintillation counting. Clinical markers of calcium and bone metabolism were measured.
High compared with low dietary protein significantly increased calcium retention from the low-calcium (29.5% compared with 26.0% absorbed) but not the high-calcium diet (18% absorbed). For the low-calcium diet, this effect nearly balanced a protein-related 0.5-mmol/d greater urinary calcium excretion. Protein-related calciuretic effects were independent of dietary calcium. Testing at 1, 2, 3, 5, and 7 wk showed no long-term adaptation in urinary acidity or urinary calcium excretion. High compared with low dietary protein decreased urinary deoxypyridinoline and increased serum insulin-like growth factor I without affecting parathyroid hormone, osteocalcin, bone-specific alkaline phosphatase, or tartrate-resistant acid phosphatase.
In healthy postmenopausal women, a moderate increase in dietary protein, from 10% to 20% of energy, slightly improved calcium absorption from a low-calcium diet, nearly compensating for a slight increase in urinary calcium excretion. Under practical dietary conditions, increased dietary protein from animal sources was not detrimental to calcium balance or short-term indicators of bone health.

Hunt JR, Johnson LK, Fariba Roughead ZK
Am. J. Clin. Nutr. May 2009
PMID: 19279077 | Free Full Text

Review: Protein – March 2003

Abstract

Protein and bone health: literature review and counselling implications.

For decades, public health promotion campaigns on bone health have emphasized the importance of adequate calcium and vitamin D intakes, as well as weight-bearing physical activity. However, no obvious consensus has emerged on the role of dietary protein. To identify what agreement does exist in the literature, in this article we review the theoretical basis for protein’s role in bone health, assess some recent cross-sectional and prospective studies, and generate recommendations for practice. There is general agreement in the literature that higher protein intake increases urinary calcium loss; the body compensates for this loss by increasing calcium absorption in the gut, providing that calcium intake is sufficient. A possible explanation for calcium loss, the “acid-ash” hypothesis, is discussed, and suggestions are made about food choices that may counter the calciuric effect of protein. A survey of cross-sectional and prospective studies shows equivocal results, with confounding variables complicating the analysis. Both deficient and excessive protein intakes have been shown to affect bone health negatively, although lower and upper thresholds have not been determined. Practical advice on achieving bone health is given, with an emphasis on the use of Canada’s Food Guide to Healthy Eating in setting dietary goals.

Cloutier GR, Barr SI
Can J Diet Pract Res 2003
PMID: 12631403