Kelsey M. Mangano

Soy proteins and isoflavones affect bone mineral density in older women: a randomized controlled trial

BACKGROUND Soy foods contain several components (isoflavones and amino acids) that potentially affect bone. Few long-term, large clinical trials of soy as a means of improving bone mineral density (BMD) in late postmenopausal women have been conducted. OBJECTIVE Our goal was to evaluate the long-term effect of dietary soy protein and/or soy isoflavone consumption on skeletal health in late postmenopausal women. DESIGN We conducted a randomized, double-blind, placebo-controlled clinical trial in 131 healthy ambulatory women aged >60 y. Ninety-seven women completed the trial. After a 1-mo baseline period, subjects were randomly assigned into 1 of 4 intervention groups: soy protein (18 g) + isoflavone tablets (105 mg isoflavone aglycone equivalents), soy protein + placebo tablets, control protein + isoflavone tablets, and control protein + placebo tablets. RESULTS Consumption of protein powder and isoflavone pills did not differ between groups, and compliance with the study powder and pills was 80-90%. No significant differences in BMD were observed between groups from baseline to 1 y after the intervention or in BMD change between equol and non-equol producers. However, there were significant negative correlations between total dietary protein (per kg) and markers of bone turnover (P < 0.05). CONCLUSIONS Because soy protein and isoflavones (either alone or together) did not affect BMD, they should not be considered as effective interventions for preserving skeletal health in older women. The negative correlation between dietary protein and bone turnover suggests that increasing protein intakes may suppress skeletal turnover. This trial was registered at ClinicalTrials.gov as NCT00668447.

Calcium Intake in the United States from Dietary and Supplemental Sources across Adult Age Groups: New Estimates from the National Health and Nutrition Examination Survey 2003-2006

BACKGROUND Adequate lifelong calcium intake is essential in optimizing bone health. Recent National Health and Nutrition Examination Survey data were used to quantify variation in calcium intake across adult age groups and to relate age-associated changes in calcium intake with energy intake. Additional goals were to assess differences in dietary calcium intake between supplemental calcium users and nonusers and to evaluate associations between age and calcium density in the diet. DESIGN This cross-sectional analysis determined calcium and energy intake for National Health and Nutrition Examination Survey respondents during 2003-2006. Diet was assessed with 24-hour recall and supplement use via questionnaire. Trends in median intakes for dietary calcium, total calcium, and energy across age categories were assessed using survey analysis methods. Nutrient density was represented using calcium to energy intake ratios. RESULTS The analyses included data from 9,475 adults. When compared to the 19- to 30-year age group, median dietary calcium intake was lower in the ≥81-year age group by 23% in men (P<0.001) and by 14% in women (P=0.003). These reductions coincided with 35% and 28% decreases, respectively, in median energy intake (P<0.001 for each sex). In contrast, the frequency of calcium supplement use increased (P<0.001) with age in both men and women. Yet, among female supplement users, the decline in median dietary calcium intake was greater than in nonusers (P=0.02). Calcium density in the diet significantly increased relative to age in men and women (P<0.001 for each sex); however, dietary and total calcium to energy ratios were insufficient to meet target ratios inferred by adequate intake standards after age 50 years. CONCLUSIONS Although supplemental calcium use and calcium density were highest in older age groups, they were not sufficient in meeting recommended levels. New approaches to increasing the frequency and level of calcium supplement use to enhance calcium density in diets may be necessary to reduce osteoporosis risk among older Americans.

Adequate dietary protein is associated with better physical performance among post-menopausal women 60-90 years

Objectives: ObjectivesSarcopenia, the involuntary loss of skeletal muscle with age, affects up to onequarter of older adults. Evidence indicates a positive association between dietary protein intake and lean muscle mass and strength among older persons, but information on dietary proteins effect on physical performance in older adults has received less attention.DesignCross-sectional observational analysis of the relationship of dietary protein on body composition and physical performance.SettingClinical research center.Participants387 healthy women aged 60–90 years (mean 72.7 ± 7.0 y).MeasurementsMeasures included body composition (fat-free mass, appendicular skeletal mass and fat mass) via dual x-ray absorptiometry (DXA), physical performance (Physical Performance Test [PPT] and Short Physical Performance Battery [SPPB]), handgrip strength, Physical Activity Scale in the Elderly (PASE), quality of life measure (SF-8), falls, fractures, nutrient and macromolecule intake (four-day food record). Independent samples t-tests determined mean differences between the above or below RDA protein groups.Statistical AnalysisAnalysis of covariance was used to control for body mass index (BMI) between groups when assessing physical performance, physical activity and health-related quality of life.ResultsThe subjects consumed an average of 72.2 g protein/day representing 1.1 g protein/kg body weight/day. Subjects were categorized as below the recommended daily allowance (RDA) for protein (defined as less than 0.8 g protein/kg) or at or above the RDA (equal to or higher than 0.8 g protein/kg). Ninety-seven subjects (25%) were in the low protein group, and 290 (75%) were in the higher protein group. Women in the higher protein group had lower body mass, including fat and lean mass, and fat-to-lean ratio than those in the lower-protein group (p <0.001). Composite scores of upper and lower extremity strength were impaired in the group with low protein intake; SPPB score was 9.9±1.9 compared to 10.6±1.6 in those with higher protein intake and PPT was 19.8± 2.9 compared to 20.9±2.1 in the low and higher protein groups, respectively. The results were attenuated by correction for BMI, but remained significant. The physical component of the SF-8 was also lower in the low protein group but did not remain significant when controlling for BMI. No significant differences were found in hand grip strength or reported physical activity.ConclusionHealthy, older postmenopausal women consumed, on average, 1.1 g/kg/d protein, although 25% consumed less than the RDA. Those in the low protein group had higher body fat and fat-to-lean ratio than those who consumed the higher protein diet. Upper and lower extremity function was impaired in those who consumed a low protein diet compared to those with a higher protein intake. Protein intake should be considered when evaluating the multi-factorial loss of physical function in older women.

Higher Protein Intake Is Associated with Higher Lean Mass and Quadriceps Muscle Strength in Adult Men and Women

BACKGROUND The impact of dietary protein intake on lower extremity lean mass and strength in community-dwelling adult Americans is not fully understood. OBJECTIVES The objective was to determine the associations between total protein (TP), animal protein (AP), and plant protein (PP) intakes and lean mass of the legs and quadriceps muscle strength. We further examined whether the associations with quadriceps strength may be explained by lean mass of the legs. METHODS This cross-sectional study included men (n = 1166) and women (n = 1509) from the Framingham Offspring Cohort in Massachusetts. Protein intake in grams per day was measured in either 1995-1998 or 1998-2001. Leg lean mass and isometric quadriceps strength, both in kilograms, were measured in 1996-2001. Multilinear regression models estimated adjusted least squares means of each of the muscle measures by quartile categories of protein intake, adjusting for relevant confounders and covariates. RESULTS Mean age was 59 ± 9 y (range: 29-86 y) and TP intake was 80 ± 27 g/d in men and 76 ± 26 g/d in women. In men and women, leg lean mass was higher in participants in the highest quartiles of TP and AP intake compared with those in the lowest quartiles of intake [least squares means (kg): TP-17.6 vs. 17.1 in men, P-trend: 0.005, and 11.7 vs. 11.4 in women, P-trend: 0.006; AP-17.6 vs. 17.1 in men, P-trend: 0.002, and 11.7 vs. 11.4 in women, P-trend: 0.003]. PP intake was not associated with lean mass in either sex. In men and women, quadriceps strength was higher in participants in the highest quartile of PP intake compared with those in the lowest quartile [least squares means (kg): 22.9 vs. 21.7 in men, P-trend: 0.01, and 19.0 vs. 18.2 in women, P-trend: 0.01]; this association was no longer significant after adjustment for fruit and vegetable intake (P-trend: 0.06 in men and 0.10 in women). Although no significant association was observed for AP intake in either sex, nonsignificant protective trends were observed for TP intake (P-trend: 0.08 in men and 0.10 in women). CONCLUSIONS Our findings suggest that maintaining adequate protein intake with age may help preserve muscle mass and strength in adult men and women. Dietary protein types may differentially affect muscle mass and strength. Whether PP is a marker of dietary quality or has a direct effect on muscle strength (independent of lean mass) needs to be further clarified.

Protective Association of Milk Intake on the Risk of Hip Fracture: Results from the Framingham Original Cohort

Dairy foods are rich in bone‐beneficial nutrients, yet the role of dairy foods in hip fracture prevention remains controversial. Our objective was to evaluate the association of milk, yogurt, cheese, cream, and milk + yogurt intakes with incident hip fracture in the Framingham Original Cohort. A total of 830 men and women from the Framingham Original Cohort, a prospective cohort study, completed a food‐frequency questionnaire (1988 to 1989) and were followed for hip fracture until 2008. In this population‐based study, Cox‐proportional hazards regression was used to estimate hazard ratios (HR) by categories of energy‐adjusted dairy intake (servings/wk), adjusting for standard confounders and covariates. The exposure was energy‐adjusted intakes of milk, yogurt, cheese, cream, and milk + yogurt (servings/wk). Risk of hip fracture over the follow‐up was the primary outcome; the hypothesis being tested was formulated after data collection. The mean age at baseline was 77 years (SD 4.9, range 68 to 96). Ninety‐seven hip fractures occurred over the mean follow‐up time of 11.6 years (range 0.04 to 21.9 years). The mean ± SD (servings/wk) of dairy intakes at baseline were: milk = 6.0 ± 6.4; yogurt = 0.4 ± 1.3; cheese = 2.6 ± 3.1; and cream = 3.4 ± 5.5. Participants with medium (>1 and <7 servings/wk) or higher (≥7 servings/wk) milk intake tended to have lower hip fracture risk than those with low (≤1 serving/wk) intake (high versus low intake HR 0.58, 95% confidence interval [CI] 0.31–1.06, p = 0.078; medium versus low intake HR 0.61, 95% CI 0.36–1.08, p = 0.071; p trend = 0.178]. There appeared to be a threshold for milk, with 40% lower risk of hip fracture among those with medium/high milk intake compared with those with low intake (p = 0.061). A similar threshold was observed for milk + yogurt intake (p = 0.104). These associations were further attenuated after adjustment for femoral neck bone mineral density. No significant associations were seen for other dairy foods (p range = 0.117 to 0.746). These results suggest that greater intakes of milk and milk + yogurt may lower risk for hip fracture in older adults through mechanisms that are partially, but not entirely, attributable to effects on bone mineral density.

Dietary protein is beneficial to bone health under conditions of adequate calcium intake: an update on clinical research.

Purpose of reviewTo underscore recent clinical studies, which evaluate the association between dietary protein and bone health. Recent findingsEpidemiologic studies show greater protein intake to be beneficial to bone health in adults. In addition, randomized controlled trials show that proteins positive effect on bone health is augmented by increased calcium intake. The relation between dietary protein and fracture risk is unclear. Dietary protein may positively impact bone health by increasing muscle mass, increasing calcium absorption, suppressing parathyroid hormone, and augmenting insulin-like growth factor 1 production; but the effects of other factors that contribute to this association, such as dietary protein dose and timing response, require further research. SummaryThe positive effects of protein intake on bone health may only be beneficial under conditions of adequate calcium intake. Dietary proteins relation with fracture risk requires further investigation.

Dietary Protein Intake Is Protective Against Loss of Grip Strength Among Older Adults in the Framingham Offspring Cohort

BACKGROUND Age-related decline in muscle strength is an important public health issue for older adults. Dietary protein has been associated with maintenance of muscle mass, yet its relation to muscle strength remains unclear. METHODS We determined the association of dietary protein (total, animal, and plant) intake, measured by food frequency questionnaire, with change in grip strength over 6 years in 1,746 men and women from the Framingham Offspring cohort. RESULTS Mean age at baseline was 58.7 years (range: 29-85), and mean total, animal, and plant protein intakes were 79, 57, and 22 g/d, respectively. Adjusted baseline mean grip strength did not differ across quartiles of energy-adjusted total, animal or protein intake. Greater protein intake, regardless of source, was associated with less decrease in grip strength (all p for trend ≤.05): participants in the lowest quartiles lost 0.17% to 0.27% per year while those in the highest quartiles gained 0.52% to 0.60% per year. In analyses stratified by age, participants aged 60 years or older (n = 646) had similar linear trends on loss of grip strength for total and animal (all p for trend <.03) but not plant protein, while the trends in participants younger than 60 years (n = 896) were not statistically significant. CONCLUSIONS Higher dietary intakes of total and animal protein were protective against loss of grip strength in community-dwelling adults aged 60 years and older. Increasing intake of protein from these sources may help maintain muscle strength and support prevention of mobility impairment in older adults.

Dietary Approaches for Bone Health: Lessons from the Framingham Osteoporosis Study.

Osteoporosis is characterized by systemic impairment of bone mass, strength, and microarchitecture, resulting in increased risk for fragility fracture, disability, loss of independence, and even death. Adequate nutrition is important in achieving and maintaining optimal bone mass, as well as preventing this debilitating disease. It is widely accepted that adequate calcium and vitamin D intake are necessary for good bone health; however, nutritional benefits to bone go beyond these two nutrients. This review article will provide updated information on all nutrients and foods now understood to alter bone health. Specifically, this paper will focus on related research from the Framingham Osteoporosis Study, an ancillary study of the Framingham Heart Study, with data on more than 5000 adult men and women.

Polyunsaturated Fatty Acids and Their Relation with Bone and Muscle Health in Adults

Age-related bone and muscle loss are major public health problems. Investigational therapies to reduce these losses include anti-inflammatory dietary supplementations, such as polyunsaturated fatty acids (PUFA). Surprisingly, this topic has received little attention in the osteoporosis community. Recent research highlights the role of PUFA in inflammatory regulation of bone remodeling via cellular pathways. Emerging research suggests significant roles for PUFA in reducing bone and muscle loss with aging; however, findings are conflicted for PUFA and fracture risk. Limited studies suggest a relation between higher omega-3 FA and better muscle/bone in older adults. This review highlights new research since 2008 and synthesizes our current understanding of PUFA in relation to bone and muscle. Across study designs, evidence indicates that PUFA has positive effects upon bone. As data are sparse, future clinical trials and prospective studies are important to determine the long term benefits of PUFA supplementation upon bone and muscle outcomes.

The effect of a whey protein supplement on bone mass in older Caucasian adults

CONTEXT It has been assumed that the increase in urine calcium (Ca) that accompanies an increase in dietary protein was due to increased bone resorption. However, studies using stable Ca isotopes have found that dietary protein increases Ca absorption without increasing bone resorption. OBJECTIVE The objective of the study was to investigate the impact of a moderately high protein diet on bone mineral density (BMD). DESIGN This was a randomized, double-blind, placebo-controlled trial of protein supplementation daily for 18 months. SETTING The study was conducted at two institutional research centers. PARTICIPANTS Two hundred eight older women and men with a body mass index between 19 and 32 kg/m(2) and a self-reported protein intake between 0.6 and 1.0 g/kg participated in the study. INTERVENTION Subjects were asked to incorporate either a 45-g whey protein or isocaloric maltodextrin supplement into their usual diet for 18 months. MAIN OUTCOME MEASURE BMD by dual-energy x-ray absorptiometry, body composition, and markers of skeletal and mineral metabolism were measured at baseline and at 9 and 18 months. RESULTS There were no significant differences between groups for changes in L-spine BMD (primary outcome) or the other skeletal sites of interest. Truncal lean mass was significantly higher in the protein group at 18 months (P = .048). C-terminal telopeptide (P = .0414), IGF-1 (P = .0054), and urinary urea (P < .001) were also higher in the protein group at the end of the study period. There was no difference in estimated glomerular filtration rate at 18 months. CONCLUSION Our data suggest that protein supplementation above the recommended dietary allowance (0.8 g/kg) may preserve fat-free mass without adversely affecting skeletal health or renal function in healthy older adults.