Alkaline diets favor lean tissue mass in older adults

Association Between Dietary Acid Load and Grip Strength in Adults 50 Years and Older: A Cross-Sectional Study

Minimal data exist on whether the acid-base balance of the diet is linked to muscle strength. The aim of this study was to determine if dietary acid load is associated with grip strength in a nationally representative sample of middle- to older-age adults. We examined the cross-sectional association of grip strength with dietary acid load quantified through potential renal acid load (PRAL) and net endogenous acid production (NEAP) in 4,059 adults aged 50 years and older in the 2011-2014 NHANES survey cycles. PRAL and NEAP were estimated from two 24-h recalls and categorized into sex-specific quartiles. Grip strength was measured on a dynamometer. Multiple linear regression models were used to determine the associations of PRAL and NEAP (as quartiles) with grip strength for men and women separately, adjusting for total energy, age, race/ethnicity, weight, physical activity, smoking, serum 25-hydroxyvitamin D, and estimated glomerular filtration rate. Mean grip strength was 26.8 ± 0.2 kg in women and 43.0 ± 0.4 kg in men. Adjusted grip strength was inversely associated with quartiles of PRAL (ptrend = 0.049) and NEAP (ptrend = 0.034) in women with quartile 4 vs 1 differences of - 1.21 and - 1.08 kg (both p < 0.05), respectively. Adjusted grip strength was not associated with PRAL or NEAP in men. Overall, we found inverse associations between dietary acid load and grip strength in middle- and older-age women, suggesting that an alkaline diet may be important in maintaining muscle strength in this population. There was no association between dietary acid load and grip strength in men.

Dietary acid load and cirrhosis-related mortality: a prospective cohort study

As a global health concern, cirrhosis contributes significantly to morbidity and mortality. This prospective cohort study aimed to investigate the association between dietary acid load (DAL) and cirrhosis-related mortality. Present study was conducted on 121 patients with newly diagnosed cirrhosis who were followed up for 48 months. Anthropometric measures, nutritional status and dietary intakes were assessed and DAL was estimated based on potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores. Crude and multivariable-adjusted hazard ratios (HR) with 95% confidence intervals (CI) were estimated using Cox proportional hazard analyses. Participants in the high PRAL and NEAP scores had significantly higher intakes of grains and lower intakes of fruits and vegetables. Also, the intake of dairy products and legumes, nuts and seeds decreased significantly with increasing NEAP score. After adjustment of all the confounders, the risk of mortality in the second and third tertiles of PRAL was 5.9 times and 10.97 higher than those in the first tertile, respectively (P trend: 0.006). Similarly, comparing the risk of mortality in the second and third tertiles with the first tertile of NEAP showed a 4.46-fold and 12.3-fold increased risk, respectively (P trend: 0.010). Our findings suggested that DAL was significantly associated with cirrhosis-related mortality and highlight the need for further research to understand the underlying mechanisms and establish optimal DAL levels in cirrhotic patients.

Immobilization by 21 days of bed rest results in type II collagen degradation in healthy individuals

OBJECTIVE

To investigate the effects of 21 days of bed rest immobilization (with and without exercise and nutrition interventions) on type II collagen biomarker concentrations in healthy individuals.

DESIGN

Twelve healthy male participants (age 34.2 ± 8.3 years; body mass index 22.4 ± 1.7 kg/m²) were exposed to 6 days ambulatory baseline data collection (BDC), 21 days head-down-tilt bed rest (HDT, CON) + interventions (HDT + resistive vibration exercise (2 times/week, 25 minutes): RVE; HDT + RVE + whey protein (0.6 g/kg body weight/day) and bicarbonate supplementation (90 mmol KHCO3/day: NeX), and 6 days of re-ambulation (R) in a cross-over designed study. The starting HDT condition was randomized (CON-RVE-NEX, RVE-NEX-CON, NEX-CON-RVE). Blood and urine samples were collected before, during, and after HDT. Serum concentrations (s) of CPII, C2C, C1,2C, and urinary concentrations (u) of CTX-II and Coll2-1NO2 were measured.

RESULTS

Twenty-one days of HDT resulted in increased sCPII (p < 0.001), sC2C (p < 0.001), and sC1,2C (p = 0.001) (highest increases: sCPII (+24.2% - HDT5), sC2C (+24.4% - HDT7), sC1,2C (+13.5% - HDT2). sC2C remained elevated at R+1 (p = 0.002) and R+6 (p < 0.001) compared to baseline. NeX led to lower sCPII (p < 0.001) and sC1,2C (p = 0.003) compared to CON. uCTX-II (second void and 24-hour urine) increased during HDT (p < 0.001, highest increase on HDT21: second void +82.8% (p < 0.001); 24-hour urine + 77.8% (p < 0.001). NeX resulted in lower uCTX-II concentrations in 24-hour urine (p = 0.012) compared to CON.

CONCLUSIONS

Twenty-one days of bed rest immobilization results in type II collagen degradation that does not recover within 6 days of resuming ambulation. The combination of resistive vibration exercise and protein/bicarbonate supplementation minimally counteracted this effect.

Effects of 8-week alkaline diet and aerobic exercise on body composition, aerobic performance, and lipid profiles in sedentary women

Background

Diet composition can affect systemic pH and acid-base regulation, which may in turn influence exercise performance.

Purpose

It was aimed to determine the effects of the alkaline diet and 8 weeks of aerobic exercises on body composition, aerobic performance, and blood lipid profiles in sedentary women.

Methods

Thirty-two sedentary women participated in the study voluntarily. The research was designed with a true-experimental design and the participants were divided into four different groups as the control group, aerobic exercise group, alkaline diet group, and alkaline diet + aerobic exercise group. The body compositions, aerobic exercise performances, and lipid profiles of sedentary women were measured as pre-test and post-test. In the analysis of the obtained data, One-Way ANOVA with Bonferroni post hoc test was used.

Results

It was observed that the alkaline diet consumed with 8 weeks of aerobic exercises caused a 5.17% decrease in BMI and an increase of 42.07 and 37.62% in VO2max and aerobic test durations, respectively (p < 0.05). In addition, when lipid profiles were examined, it was determined that there was no statistically significant difference in HDL-C levels (p > 0.05). Despite that, there were statistically significant differences in TG and LDL-C levels (p < 0.05). According to this result, it was determined that there was a decrease in TG and LDL-C levels by 37.61 and 20.24%, respectively.

Conclusion

An alkaline diet consumed with 8 weeks of aerobic exercises in sedentary women has positive effects on improving body composition, aerobic exercise performances, and TG and LDL-C levels.

Anti-inflammatory dietary pattern is associated with handgrip strength decline: a prospective cohort study

BACKGROUND AND AIMS

Skeletal muscle strength decline is strongly associated with inflammation. While previous research has confirmed that diet can modulate chronic inflammation, little is known about the relationship between an anti-inflammatory dietary pattern and muscle strength. The aim of this study was to investigate the association between an anti-inflammatory dietary pattern and handgrip strength decline in a large-scale adult population.

METHODS

During a median follow-up period of 3 years, this prospective cohort study was carried out between 2013 and 2018 and included 2840 participants (60.2% men). Dietary intake was assessed using a validated food frequency questionnaire at baseline, and handgrip strength was measured annually with a handheld digital dynamometer. The dietary inflammatory potential score was calculated using white blood cell count and hypersensitive C-reactive protein as inflammatory markers, and was determined using reduced rank regression and stepwise linear regression. Multivariable linear regression models were used to estimate the association between the dietary inflammatory potential score and the annualized change in handgrip strength and weight-adjusted handgrip strength.

RESULTS

After adjusting for multiple confounding factors, significant associations between the dietary inflammatory potential score and the annualized change in handgrip strength and weight-adjusted handgrip strength in women, with values of - 0.8322 kg (95% confidence interval [CI] - 1.6405, - 0.0238; P < 0.0408) and - 0.0171 kg/kg (95% CI - 0.0310, - 0.0032; P < 0.0158), respectively. However, no significant differences were observed between the dietary inflammatory potential score and the annualized change in handgrip strength and weight-adjusted handgrip strength in men, with values of 0.1578 kg (95% CI - 0.6107, 0.9261; P < 0.6874) and - 0.0014 kg/kg (95% CI - 0.0115, 0.0088; P < 0.7933), respectively.

CONCLUSION

Our findings suggest that consuming an anti-inflammatory dietary pattern could be a protective strategy against the decline in skeletal muscle strength in women.

Cross-Sectional Study on the Association between Dietary Patterns and Sarcopenia in Elderly Patients with Chronic Kidney Disease Receiving Conservative Treatment

Sarcopenia is a poor prognostic factor in patients with chronic kidney disease (CKD). Adequate dietary patterns are important for preventing sarcopenia; however, evidence regarding the underlying association between sarcopenia and diet is insufficient. Therefore, in this study, we aimed to investigate the association between sarcopenia and dietary patterns in CKD patients receiving conservative treatment. In this cross-sectional study, 441 patients with conservative CKD were examined using the Asian Working Group for Sarcopenia diagnostic criteria. CKD was defined as an eGFR of <60 mL/min/1.73 m2 present for >3 months. The participants were divided into sarcopenia and non-sarcopenia groups, and dietary patterns were compared between the two groups using the dietary variety score, a simple dietary survey method that investigates the weekly frequency of consumption of 10 food groups. Logistic regression analysis for CKD G3 showed that female sex (odds ratio (OR): 0.166, 95% confidence interval (CI): 0.086-0.320), increased body mass index (OR: 0.663, 95% CI: 0.590-0.745), and almost daily consumption of green/yellow vegetables (OR: 0.350, 95% CI: 0.176-0.695) were positively associated with non-sarcopenia. Although further prospective studies are required, the results suggest that low frequent consumption of vegetables is associated with sarcopenia in patients with CKD.

Dietary acid load in children with chronic kidney disease: its association with nutritional status and health-related quality of life

BACKGROUND

This study aimed to determine the dietary acid load of children with chronic kidney disease (CKD) and to evaluate the relationship between dietary acid load, nutritional status, and health-related quality of life (HRQOL).

METHOD

A total of 67 children aged 3-18 years with a diagnosis of CKD stages II-V were included in the study. Anthropometric measurements (body weight, height, mid-upper arm circumference, waist, and neck circumference) and 3-day food consumption records were taken to evaluate the nutritional status. The net endogenous acid production (NEAP) score was calculated to determine the dietary acid load. "Pediatric Inventory of Quality of Life (PedsQL)" was used to assess the participants' HRQOL.

RESULTS

The mean NEAP was 59.2 ± 18.96 mEq/day. Stunted and malnourished children had significantly higher NEAP than those who were not (p < 0.05). There were no significant differences in terms of HRQOL scores according to NEAP groups. The multivariate logistic regression analysis showed that waist circumference (OR: 0.890, 95% CI: 0.794-0.997), serum albumin (OR: 0.252, 95% CI: 0.068-0.929), and glomerular filtration rate (GFR) (OR: 0.985, 95% CI: 0.970-1.000) were negatively associated with high NEAP.

CONCLUSION

This study shows that a diet shifted in an acidic direction in children with CKD and a higher dietary acid load are associated with lower serum albumin, GFR, and waist circumference, but not HRQOL. These results suggest that dietary acid load might affect nutritional status and CKD progression in children with CKD. Future studies with larger samples are needed to confirm these results and to understand underlying mechanisms. A higher resolution version of the Graphical abstract is available as Supplementary information.

Dietary acid load is associated with waist circumference in university students with low adherence to the Mediterranean diet: The potential role of ultra-processed foods

BACKGROUND AND AIMS

Dietary acid load (DAL), as expressed by potential renal acid load (PRAL) and net acid production (NEAP), is connected to cardiometabolic disorders and obesity. Mediterranean diet relates to lower, while western diets to higher DAL values. The present study aimed to assess the association of PRAL and NEAP with adiposity measures in young adults (19.61 ± 3.15 years, mean ± standard deviation) and explore the implication of Mediterranean diet adherence and ultra-processed foods (UPF) intake in this relation.

METHODS

346 students (269 women) participated. Anthropometry was performed, and a food frequency questionnaire was administered. The MedDietScore was calculated, UPF consumption was calculated based on the NOVA classification and PRAL/NEAP was estimated from published equations. Waist Circumference (WC) was transformed to WC^-1 (1/WC) in order to achieve normality and run linear regression models.

RESULTS

In subjects with MedDietScore ≤ 28.00, PRAL and NEAP were negatively associated with 1/WC (B = -1.594 × 10-5± 8 × 10-6, p = 0.044 for PRAL and B = -2.84 × 10-5 ± 1 × 10-5, p = 0.048 for NEAP). Moreover, in this subgroup, subjects with medium to high UPF intake i.e., in the 2nd or 3rd tertile of UPF intake representing more than 34.16% of energy, PRAL (2nd tertile B = -0.00007, SE = 0.00003, p = 0.018; 3rd tertile B = -0.00002, SE = 0.00001, p = 0.024) and NEAP (2nd tertile B = -0.00004, SE = 0.00002, p = 0.040; 3rd tertile B = -0.00007, SE = 0.00004, p = 0.055) were connected to central obesity. In similar models, PRAL and NEAP were not significant predictors of BMI.

CONCLUSION

The DAL may be related to central obesity, especially in individuals with worse dietary quality, as reflected by lower adherence to the Mediterranean diet, and high intake of UPF. Nutrition guidance aiming at the reduction of DAL may be useful in the reduction of central obesity in these subgroups.

A Randomized Study on the Effect of Dried Fruit on Acid-Base Balance, Diet Quality, and Markers of Musculoskeletal Health in Community Dwelling Adults

OBJECTIVES

We tested whether 100 g/day of dried fruit (vs. no supplemental fruit control) for 6 months alters 24-hr urinary net acid excretion (NAE), bone resorption, weight, body composition, muscle performance, and diet quality. We explored consistency of self-selected dietary composition and potential renal acid load (PRAL).

METHODS

This randomized, single-blind, 2-armed study included 83 normal- and over-weight men and postmenopausal women (age ≥50 years) on self-reported low fruit diets. Endpoints included group differences in NAE (primary), 24-hr urinary N-telopeptide (NTX), weight, body composition, muscle performance, and diet quality.

RESULTS

At baseline, mean (±SD) age was 69 ± 8 years; 86% were Caucasian; body mass index was 24.5 ± 2.8 kg/m²; 46% female, and NAE was 32.4 ± 23.1 mmol with no significant baseline group differences. No significant group differences were noted in NAE (primary), NTX, weight, body composition, muscle performance or diet quality at 6 months. In the cohort as a whole, 6-month change in NAE was positively associated with change in NTX, but no significant associations were noted in other outcomes. PRAL on the day of the urine collection was positively associated with NAE. Comparison of two consecutive baseline 24-hr diet recalls revealed wide intra-individual variability in PRAL in self-selected diets in our participants.

CONCLUSION

In this field study of older adults consuming self-selected diets, making one change to the diet by adding 100 g/day of dried fruit (equivalent to 4 servings per day) had no significant impact on NAE when compared to a no supplemental fruit control. This null finding may be attributable to the high day-to-day variability in consumption of foods affecting NAE. Added fruit also had no significant effect on weight, fat, muscle, or bone outcomes over a 6-month period.

Patterns of Dietary Blood Markers Are Related to Frailty Status in the FRAILOMIC Validation Phase

The influence of nutritional factors on frailty syndrome is still poorly understood. Thus, we aimed to confirm cross-sectional associations of diet-related blood biomarker patterns with frailty and pre-frailty statuses in 1271 older adults from four European cohorts. Principal component analysis (PCA) was performed based on plasma levels of α-carotene, β-carotene, lycopene, lutein + zeaxanthin, β-cryptoxanthin, α-tocopherol, γ-tocopherol and retinol. Cross-sectional associations between biomarker patterns and frailty status, according to Fried's frailty criteria, were assessed by using general linear models and multinomial logistic regression models as appropriate with adjustments for the main potential confounders. Robust subjects had higher concentrations of total carotenoids, β-carotene and β-cryptoxanthin than frail and pre-frail subjects and had higher lutein + zeaxanthin concentrations than frail subjects. No associations between 25-Hydroxyvitamin D3 and frailty status were observed. Two distinct biomarker patterns were identified in the PCA results. The principal component 1 (PC1) pattern was characterized by overall higher plasma levels of carotenoids, tocopherols and retinol, and the PC2 pattern was characterized by higher loadings for tocopherols, retinol and lycopene together and lower loadings for other carotenoids. Analyses revealed inverse associations between PC1 and prevalent frailty. Compared to participants in the lowest quartile of PC1, those in the highest quartile were less likely to be frail (odds ratio: 0.45, 95% CI: 0.25-0.80, p = 0.006). In addition, those in the highest quartile of PC2 showed higher odds for prevalent frailty (2.48, 1.28-4.80, p = 0.007) than those in the lowest quartile. Our findings strengthen the results from the first phase of the FRAILOMIC project, indicating carotenoids are suitable components for future biomarker-based frailty indices.

The association between dietary acid load and body composition in physical education students aged 18-25 years

AIM

To find the association between dietary acid load (DAL) and body composition in physical education students.

METHODS

This study was carried out on 207 students of both genders aged 18-25 years. DAL was calculated based on potential renal acid load (PRAL) and net endogenous acid production (NEAP) methods. Anthropometric indices were measured. Bioelectric impedance was used to assess body composition and other related items.

RESULTS

The mean score of NEAP and PRAL was 80.18 ± 31.30 and 33.94 ± 22.11, respectively. The mean weight and fat mass of subjects were 64.05 ± 9.72 kg and 20.28 ± 0.67 kg, respectively. Participants in the highest tertile of PRAL had a higher weight (64.56 ± 1.14 kg) in comparison with participants in the lowest tertile (61.65 ± 1.19 kg) (P = 0.027). After adjusting for confounders, a significant positive association was found between NEAP score and hip circumference (β = 0.206, P = 0.039), body mass index (β = 0.214, P = 0.031), fat mass (β = 0.218, P = 0.001) and body adiposity index (β = 0.182, P = 0.037). Furthermore, a statistically significant negative association was observed between total body water and NEAP score (β = - 0.217, P = 0.001) and the percentage of fat-free mass and NEAP (β = - 0.229, P = 0.001).

CONCLUSION

Individuals with a higher DAL score may have a higher weight, fat mass and hip circumference and a lower fat-free mass. In addition, there might be an association between DAL and obesity.

Chronic Sub-Clinical Systemic Metabolic Acidosis - A Review with Implications for Clinical Practice

When arterial serum pH remains near the lower pH limit of 7.35 for protracted periods of time, a low-grade, sub-clinical form of acidosis results, referred to in this review as chronic, sub-clinical, systemic metabolic acidosis (CSSMA). This narrative review explores the scientific basis for CSSMA, its consequences for health, and potential therapeutic interventions. The major etiology of CSSMA is the shift away from the ancestral, alkaline diet which was rich in fruit and vegetables, toward the contemporary, acidogenic 'Westernized' diet characterized by higher animal protein consumption and lack of base forming minerals. Urine pH is reduced with high dietary acid load and may be a convenient marker of CSSMA. Evidence suggests further that CSSMA negatively influences cortisol levels potentially contributing significantly to the pathophysiology thereof. Both CSSMA and high dietary acid load are associated with the risk and prognosis of various chronic diseases. Clinical trials show that CSSMA can be addressed successfully through alkalizing the diet by increasing fruit and vegetable intake and/or supplementing with alkaline minerals. This review confirms the existence of a significant body of evidence regarding this low-grade form of acidosis as well as evidence to support its diverse negative implications for health, and concludes that CSSMA is a condition warranting further research.

Association of Longitudinal Nutrient Patterns with Body Composition in Black Middle-Aged South African Women: A Five-Year Follow-Up Study

This study aimed to evaluate the association of longitudinal nutrient patterns with body composition in a cohort of 132 black South African middle-aged women over five years. Nutrient patterns were identified using principal component analysis at baseline and follow-up 5 years later. Associations between nutrient patterns and repeated body composition measures were evaluated using generalized estimating equations, before and after adjusting for baseline education and repeated measures of age, socio-economic status, physical activity and employment. The animal-driven nutrient pattern was associated with increases in repeated measures of visceral adipose tissue (VAT) (β coefficient, 5.79 [95% CI, 0.01-11.57] cm²), fat mass index (FMI) (0.47 [0.01-0.93] kg·m^-2) and lean mass index (LMI) (0.50 [0.18-1.17] kg·m^-2) (p < 0.05) after adjustment. Vitamin C, sugar, and potassium-driven nutrient pattern was associated with higher FMI (0.50 [0.12-0.88] kg·m^-2) and LMI (0.58 [0.07-1.10] kg·m^-2) before and after adjustment (p < 0.05). These findings suggest that dietary interventions to curb obesity in black middle-aged South African women should focus on attenuation of nutrient patterns centred on added sugar, animal fat and animal protein.

The association between dietary acid load and adiposity measures among children and adolescents

Background

Childhood obesity is one of the most important health problems in the present century. It is imperative to plan preventive programs through risk factor identification. The present study was conducted to examine the association between the dietary acid load (DAL) and anthropometric indices in a sample of Iranian children and adolescents.

Methods

In the current survey, students aged 11–18 years were recruited. To assess usual dietary intake, a validated self-administered 168-item food frequency questionnaire was used. Potential renal acid load (PRAL) and net endogenous acid production (NEAP) was used to estimate DAL. The association between DAL and anthropometric indices was evaluated using logistic regression and reported as an odds ratio (OR) with a 95% confidence interval (CI).

Results

In total, 456 students (267 girls), with a mean age of 14.44 years participated in the current study. After controlling for potential confounders, the PRAL was positively associated with the risk of obesity (OR = 4.56, 95% CI: 2.26, 9.17), abdominal obesity (OR = 12.64, 95% CI: 3.05, 52.27), and adiposity based on the percent of body fat (PBF) (OR = 3.58, 95% CI: 1.83, 6.99). The NEAP was also significantly associated with the risk of obesity (OR = 5.17, 95% CI: 2.56, 10.43), abdominal obesity (OR = 15.08, 95% CI: 3.35, 67.81), and adiposity based on PBF (OR = 4.53, 95% CI: 2.30, 8.92).

Conclusion

Our findings suggest that higher adherence to the acidogenic diet, expressed as DAL, was associated with a higher risk of general and central obesity among children and adolescents.

Association of abdominal muscle area and density with glucose regulation: The multi-ethnic study of atherosclerosis (MESA)

AIMS

Previous characterisation of body composition as a type 2 diabetes mellitus (T2DM) risk factor has largely focused on adiposity, but less is known about the independent role of skeletal muscle. We examined associations between abdominal muscle and measures of glucose regulation.

MATERIALS AND METHODS

Cross-sectional analysis of 1,891 adults enrolled in the Multi-Ethnic Study of Atherosclerosis. Multivariable regression assessed associations between abdominal muscle area and density (measured by computed tomography) with fasting glucose, homeostasis model assessment of insulin resistance (HOMA-IR), and prevalent T2DM (fasting glucose ≥126 mg/dL or medication use).

RESULTS

In minimally adjusted models (age, sex, race/ethnicity, income), a 1-SD increment in abdominal muscle area was associated with higher HOMA-IR (β = 0.20 ± SE 0.03; 95%CI: 0.15, 0.25; P < 0.01) and odds of T2DM (OR = 1.47; 95%CI: 1.18, 1.84; P < 0.01), while higher density was associated with lower fasting glucose (-4.49 ± 0.90; -6.26, -2.72; P < 0.01), HOMA-IR (-0.16 ± 0.02; -0.20, -0.12; P < 0.01), and odds of T2DM (0.64; 0.52, 0.77; P < 0.01). All associations persisted after adjustment for comorbidities and health behaviours. However, after controlling for height, BMI, and visceral adiposity, increasing muscle area became negatively associated with fasting glucose (-2.23 ± 1.01; -4.22, -0.24; P = 0.03), while density became positively associated with HOMA-IR (0.09 ± 0.02; 0.05, 0.13; P < 0.01).

CONCLUSIONS

Increasing muscle density was associated with salutary markers of glucose regulation, but associations inverted with further adjustment for body size and visceral adiposity. Conversely, after full adjustment, increasing muscle area was associated with lower fasting glucose, suggesting some patients may benefit from muscle-building interventions.

24-hour sodium and potassium excretion in the Americas: a systematic review and meta-analysis

Objective

To determine the 24-hour urinary sodium and potassium excretions in the Americas.

Methods

A systematic review and meta-analysis were performed seeking for studies conducted between 1990 and 2021 in adults living in any sovereign state of the Americas in Medline, Embase, Scopus, SciELO, and Lilacs. The search was first run on October 26^th, 2020 and was updated on December 15^th, 2021. Of 3 941 abstracts reviewed, 74 studies were included from 14 countries, 72 studies reporting urinary sodium (27 387 adults), and 42 studies reporting urinary potassium (19 610 adults) carried out between 1990 and 2020. Data were pooled using a random-effects meta-analysis model.

Results

Mean excretion was 157.29 mmol/24h (95% CI, 151.42-163.16) for sodium and 57.69 mmol/24h (95% CI, 53.35-62.03) for potassium. When only women were considered, mean excretion was 135.81 mmol/24h (95% CI, 130.37-141.25) for sodium and 51.73 mmol/24h (95% CI, 48.77-54.70) for potassium. In men, mean excretion was 169.39 mmol/24h (95% CI, 162.14-176.64) for sodium and 62.67 mmol/24h (95% CI, 55.41-69.93) for potassium. Mean sodium excretion was 150.09 mmol/24h (95% CI, 137.87-162.30) in the 1990s and 159.79 mmol/24h (95% CI, 151.63-167.95) in the 2010s. Mean potassium excretion was 58.64 mmol/24h (95% CI, 52.73-64.55) in the 1990s and 56.33 mmol/24/h (95% CI, 48.65-64.00) in the 2010s.

Conclusions

These findings suggest that sodium excretions are almost double the maximum level recommended by the World Health Organization and potassium excretions are 35% lower than the minimum requirement; therefore, major efforts to reduce sodium and to increase potassium intakes should be implemented.

Nutritional Concerns for Cancer, Cachexia, Frailty, and Sarcopenia in Canine and Feline Pets

Cachexia and frailty can be described as independent entities yet are interrelated as constituents of malnutrition and the aging process. The unifying aspect is lean muscle loss, ultimately driven by inflammation and the adverse ramifications to pets with chronic, debilitating, or terminal disease states, including cancer. Modification to intake of dietary protein, fat, omega-3 fatty acids, and selected vitamins has shown benefit in management protocols as preventative and palliative care, but further investigation is imperative.

Association of dietary acid load with anthropometric indices in children and adolescents

PURPOSE

High dietary acid load (DAL) may have an influence on anthropometric indices. Given that there was no study on the association between DAL and anthropometric indices children and adolescents, the current study was aimed to examine the association between DAL and anthropometric indices in Iranian children and adolescents.

METHODS

Students aged 6-18 years were recruited using a multi-stage, cluster sampling method from 30 provinces of Iran. Dietary intake was assessed through a validated food frequency questionnaire. Height (Ht), weight (Wt), neck circumference (NC), waist circumference (WC), wrist circumference, and hip circumference (HC) were measured. WC-to-HC ratio (WHR), WC-to-Ht ratio (WHtR), body mass index (BMI) z-score, tri-ponderal mass index (TMI), and parental BMI were computed. Potential renal acid load (PRAL) and net endogenous acid production (NEAP) were used to estimate DAL. The association between DAL and anthropometric indices was evaluated using linear regression models.

RESULTS

In total, 5326 students (46.92% girls), with mean (standard deviations (SD)) age of 12.50 (3.14) years participated in the study (response rate: 98.13%). After adjusting for confounders, there was a significant association between NEAP and NC (P < 0.05). Also, an inverse association was observed between PRAL and NEAP with parental BMI (P < 0.05).

CONCLUSION

Our findings showed a direct association between diet-induced acid load and NC and an inverse association between DAL indices and parental BMI. More well-designed clinical studies are warranted to confirm our results and the underlying mechanisms.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Mediterranean Diet In Healthy Aging

The World elderly population is expected to double before 2050. Unhealthy habits and unhealthy lifestyles are commonly associated with age-related diseases or their worsening. Modification in daily lifestyle and diet may help preventing age-related diseases onset and efficiently affecting their evolution, thus promoting the Healthy Aging process, concept recently coined to describe the disease-free aging process. This review highlights the role of nutrition science in promoting healthy aging. Since the Mediterranean Model demonstrated to be a useful style in supporting healthy aging, promotion of this correct lifestyle by health policies seems to be the best approach to achieve this target.

The association between healthy lifestyle score with cardiorespiratory fitness and muscle strength

OBJECTIVE

The association of individual behaviours such as diet, tobacco use, body mass index (BMI) and physical activity have been investigated separately in relevance to cardiorespiratory fitness (CRF) and muscle strength. The purpose of this study is to investigate the combined association of the four mentioned lifestyle factors with cardiorespiratory fitness and muscle strength.

METHODS

This cross-sectional study was conducted on 271 Iranian adults, aged 18-70 years. We developed a healthy lifestyle score (HLS) that ranged from 0 to 103 (higher score reflecting better adherence to healthier lifestyle) and included four lifestyle behavioural components (diet, physical activity, smoking and BMI). The relationship between HLS, CRF and muscle strength was determined using linear and non-linear regression analysis.

RESULTS

HLS score was not significantly associated with VO_2max (mL/kg/min) P = .43; VO_2max (L min) P = .14; VO_2max (LBM) (P = .79) and mean muscle strength (MMS) (kg) (P = .11), muscle strength of right hand (MSR) (kg) (P = .10) and muscle strength of left hand (MSL) (kg) (P = .16) in the unadjusted model. After adjustment for potential confounders, we found a significant association between HLS and Vo_2max (L/min), MMS (kg), MSR (kg) and MSL (kg) (P < .001 for all). Also HLS and MMS (r = .06, P = .31), MSR (r = .07, P = .25), MMS (r = .05, P = .39), VO_2max (mL/kg/min) (r = .01, P = .77), VO_2max (L min) (r = .05, P = .35) and VO_2max (LBM) (r = .002, P = .91) have no statistically significant linear relationship.

CONCLUSION

Adherence to healthy lifestyle may be associated with increased CRF and muscle strength after adjusting for potential confounding variables.

Longitudinal Association Between Sodium and Potassium Intake and Physical Performance in Older Adults

BACKGROUND

Aging is associated with a progressive difficulty to maintain ion regulation, which might impair the capacity for muscle contraction. Thus, the aim of this study was to examine the association between 5-year changes in dietary intake of sodium and potassium and changes in physical performance among older adults.

METHODS

We performed a prospective study with 868 participants from the Seniors-ENRICA cohort. Diet was measured with a validated diet history and physical performance was measured with the Short Physical Performance Battery (SPPB), both in 2012 and 2017. Analyses were performed with linear regression models adjusted for sociodemographic variables, lifestyle, and morbidity, using changes in the intake of sodium and potassium and changes in the sodium/potassium ratio during follow-up as independent variables, and the continuous change in the SPPB score as the dependent variable.

RESULTS

Over 5 years of follow-up, a 1 SD increase in sodium intake (ie, 0.73 g/d) was associated with a 0.13 (95% confidence interval [CI]: 0.26-0.01) points reduction in the SPPB score, while a 1 SD increase in potassium intake (ie, 0.70 g/d) was associated with a 0.19 (0.05-0.34) points increment in the score. In addition, a 1 SD increase in the sodium-to-potassium ratio (ie, 0.30) was associated with worse SPPB (-0.58 [-0.95 to -0.21]). Participants who adhered to dietary recommendations for minerals at baseline but became noncompliant during follow-up decreased their result in the SPPB.

CONCLUSION

An increase of dietary sodium intake, a decrease of potassium intake and the resulting increment in the sodium-to-potassium ratio were prospectively associated with worse physical performance in older adults.

Association of dietary approaches to stop hypertension eating style and risk of sarcopenia

The association between habitual intake of the “dietary approaches to stop hypertension” (DASH) eating plan and sarcopenia has received limited attention. The present study aimed to investigate the association between adherence to DASH dietary pattern and sarcopenia and its components including muscle mass, muscle strength, and muscle performance among community-dwelling older adults population. This population-based cross-sectional study was performed in 2011 among 300 older people (150 men and 150 women) aged ≥ 55 years, who were selected using cluster random sampling method. Dietary intake of study participants were examined by the use of a Block-format 117-item food frequency questionnaire (FFQ). The DASH score was constructed based on eight main foods and nutrients emphasized or minimized in the DASH diet. All components of sarcopenia was measured using standard protocols and sarcopenia was defined based on both former and new European Working Group on Sarcopenia in Older People (EWGSOP) guidelines. Mean age and BMI of study participants were 66.7 ± 7.7 years and 27.3 ± 4.2 kg/m², respectively. Totally, 31 individuals meet the criteria of EWGSOP2-sarcopenia. We found no significant association between adherence to the DASH diet and EWGSOP2-sarcopenia either before (OR 1.08; 95% CI 0.45–2.54) or after adjustment for potential confounders (OR 1.04; 95% CI 0.39–2.75). The same findings were obtained in the gender-stratified analyses (men: OR 2.29; 95% CI 0.39–13.29 and women: 0.75; 95% CI 0.23–2.45). In conclusion, we found that adherence to the DASH-style diet was not significantly associated with odds of sarcopenia. Future prospective studies are required to confirm these findings.

The association between dietary acid load and muscle strength among Iranian adults

OBJECTIVE

There is limited evidence regarding the association between dietary acid load and muscle strength. Thus, in this study, we investigated the association between dietary acid-base load indices and muscle strength among Iranian adults.

RESULTS

This cross-sectional study was conducted on 270 Iranian adults, aged 18-70 year. Dietary acid load indexes, were calculated by using a validated 168-item semi-quantitative food frequency questionnaire (FFQ). Muscle strength was measured by a digital handgrip dynamometer. There was a significant increase in mean muscle strength of left-hand (MSL), muscle strength of right-hand (MSR) and the mean of the MSL and MSR (MMS) across tertiles of Potential Renal Acid Load (PRAL), Net Endogenous Acid Production (NEAP), and Dietary Acid Load (DAL). Significant linear relationships between PRAL and; MSL (β = 0.24, p < 0.001), MSR (β = 0.23, p < 0.001) and MMS (β = 0.24, p < 0.001), between NEAP and MSL (β = 0.21, p < 0.001), MSR (β = 0.19, p = 0.002), and MMS (β = 0.20, p = 0.001) and between DAL and MSL (β = 0.25, p < 0.001), MSR (β = 0.23, p < 0.001) and MMS (β = 0.24, p < 0.001), were attenuated after controlling for potential confounders. However, the nonlinear relationship between dietary acid load indicators and muscle strength were significant (p < 0.001 for all).

Dietary acid-base load and its association with risk of osteoporotic fractures and low estimated skeletal muscle mass

BACKGROUND/OBJECTIVES

Age-related decline in skeletal muscle mass and strength, loss of bone density, and increased risk of osteoporotic fractures are important public health issues. Systemic acid-base balance is affected by dietary intake and may be relevant to these conditions. We therefore investigated associations of dietary acid-base load with skeletal muscle mass, bone density status, and fracture risk.

SUBJECTS/METHODS

We analysed the European Prospective Investigation into Cancer and Nutrition-Norfolk cohort of >25,000 individuals, 39-79 years at baseline. Potential renal acid load (PRAL) was calculated from 7-day food diary data. As a proxy for skeletal muscle mass, we estimated fat-free mass from bioelectrical impedance analysis and scaled this for BMI (FFM_BMI). Bone density status was assessed by heel-bone broadband ultrasound attenuation (BUA), and fracture rates were obtained from health-care records. Multivariable regression was used to test musculoskeletal outcomes across sex-specific quintiles of PRAL.

RESULTS

PRAL in quintiles was negatively associated with FFM_BMI in men (n = 6350, p < 0.001) and women (n = 7989, p < 0.001), with quintile 5 vs 1 differences of -1.5% and -3.2% (both p < 0.001). PRAL was also negatively associated with BUA in women (n = 8312, p = 0.016; quintile 5 vs 1 difference -1.5%, p = 0.024). The combined hazard of hip, wrist and spine fractures (mean ± SD follow-up 17.9 ± 4.9 years) was higher with increasing quintiles of PRAL in men (610 fractures; n = 11,511; p = 0.013) and women (1583 fractures; n = 13,927; p = 0.009), with quintile 5 vs 1 hazard ratios of 1.33 (95% CI: 1.03-1.72, p = 0.029) and 1.21 (95% CI: 1.03-1.42, p = 0.022), but associations were not consistent for all fractures sites and age groups tested.

CONCLUSIONS

This study provides strong evidence, albeit observational, for a negative association between PRAL and musculoskeletal health in middle to older age men and women, and thus supports the rationale for a less acidic dietary load.

Effects of dietary protein-load and alkaline supplementation on acid-base balance and glucose metabolism in healthy elderly

BACKGROUND/OBJECTIVES

Metabolism is controlled by macro- and micronutrients. Protein-rich diets should lead to latent acidosis at tissue level with further negative implications. Food supplements with alkaline salts are available and popular pretending to prevent these changes.

SUBJECTS/METHODS

Within a randomised double-blind placebo-controlled trial we tested the hypotheses that (1) a 4-week protein-rich diet induces a latent tissue acidosis and (2) an alkaline supplement can compensate this. Acid-base balance and important metabolic parameters were determined before and after 4 weeks of supplementation by peripheral blood samples, indirect calorimetry and muscle microdialysis before and after a protein-rich test meal.

RESULTS

Fourty volunteers were randomised 1:1 to either verum or placebo supplements. Protein-rich diet by itself did not significantly affect acid-base balance. Alkaline supplementation increased plasma bicarbonate concentration without changing pH. Postprandial increases in serum glucose and insulin tended to be lower for verum vs. placebo. Resting and postprandial energy metabolism, and carbohydrate and fat oxidation did not differ significantly before and after supplementation in both groups. In muscle, postprandial glucose uptake and aerobic glucose oxidation were significantly higher for verum. In addition, verum significantly increased serum magnesium concentrations.

CONCLUSIONS

Four weeks of protein-rich diet did not significantly influence acid-base balance. However, alkaline supplementation improved systemic and tissue acid-base parameters and oxidative glucose metabolism.

Potassium intake, skeletal muscle mass, and effect modification by sex: data from the 2008-2011 KNHANES

BACKGROUND

A loss of muscle mass may be influenced by multiple factors. Insulin sensitivity and metabolic acidosis are associated with muscle wasting and may be improved with potassium intake. This study evaluated the association between dietary potassium intake and skeletal muscle mass.

METHODS

We performed a cross-sectional study with data obtained from the Korean National Health and Nutrition Examination Survey (KNHANES) (2008-2011). Participant's daily food intake was assessed using a 24-h recall method. Appendicular skeletal muscle mass (ASM) was calculated as the sum of muscle mass in both arms and legs, measured using dual energy X-ray absorptiometry. The skeletal muscle index (SMI) was calculated as ASM divided by height2 (kg/m2). Low muscle mass was defined as a SMI < 7.0 kg/m2 for men and < 5.4 kg/m2 for women.

RESULTS

Data from 16,558 participants (age ≥ 19 years) were analyzed. Participants were categorized into quintiles according to their potassium intake. Sex-specific differences were found in the association between potassium intake and muscle mass (PInteraction < 0.001). In men, higher potassium intake was associated with lower odds for low muscle mass; the fully adjusted odds ratios (95% confidence intervals) were 0.78 (0.60-1.03), 0.71 (0.54-0.93), 0.68 (0.51-0.90), and 0.71 (0.51-0.98) for the top four quintiles (referenced against the lowest quintile), respectively. However, this association was attenuated in women after adjusting for total energy intake. Higher potassium intakes were also associated with a greater SMI.

CONCLUSIONS

Higher dietary potassium intake decreased the odds of low muscle mass in men but not in women.

Nutrition and Sarcopenia-What Do We Know?

Muscle health is important for the functionality and independence of older adults, and certain nutrients as well as dietary patterns have been shown to offer protective effects against declines in strength and function associated with aging. In this paper, micronutrients, macronutrients, and food groups have been reviewed, along with their studied effects on the prevalence and incidence of sarcopenia, as well as their ability to preserve muscle mass and optimize physical performance. Randomized controlled trials appear to suggest a critical role for dietary intake of protein in preventing sarcopenia and muscle loss, although the optimal dose and type of protein is unknown. There are some promising data regarding the role of vitamin D and sarcopenia, but it is unclear whether the dose, frequency of dose, or length of treatment impacts the efficacy of vitamin D on improving muscle mass or function. Selenium, magnesium, and omega 3 fatty acids have been studied as supplements in clinical trials and in the diet, and they appear to demonstrate a potential association with physical activity and muscle performance in older individuals. Following the Mediterranean diet and higher consumption of fruits and vegetables have been associated with improved physical performance and protection against muscle wasting, sarcopenia, and frailty.

Associations of protein source, distribution and healthy dietary pattern with appendicular lean mass in oldest-old men: the Helsinki Businessmen Study (HBS)

PURPOSE

We explored how food and dietary intakes, protein daily distribution and source are associated with appendicular lean mass (ALM)/m² of the oldest-old community-dwelling men.

METHODS

Cross-sectional analyses of Helsinki Businessmen Study (HBS, mean age 87 years) participants who came to clinic visit in 2017/2018. Nutritional status, physical performance and fasting blood samples were measured. Food and dietary intakes were retrieved from 3-day food diaries. Body composition was measured and appendicular lean mass (ALM) per m² was dichotomized as ALM/m² < 7 kg/m² and ≥ 7 kg/m². Differences between lower and higher ALM were analyzed using t test or Mann-Whitney U test. Analysis of covariance was used to investigate independent associations with ALM/m².

RESULTS

Random sample of 130 participants took part in the medical examinations, 126 returned food diaries, and 102 underwent DXA-scan. ALM/m² was associated with total protein (p = 0.033), animal protein (p = 0.043) and meat protein (p = 0.033) intakes. Protein distribution between daily meals differed at lunch; those with higher ALM/m² ate more protein (p = .047) at lunch. Consumption of fruits, vegetables (p = 0.022) and meat (p = 0.006) was associated with ALM/m².

CONCLUSION

Protein intake, source and distribution as well fruit and vegetable intakes were associated with higher ALM in oldest-old men.

STUDY REGISTRATION

The study is registered with ClinicalTrials.gov identifier: NCT02526082.

Dietary Intakes of Vegetable Protein, Folate, and Vitamins B-6 and B-12 Are Partially Correlated with Physical Functioning of Dutch Older Adults Using Copula Graphical Models

BACKGROUND

In nutritional epidemiology, dealing with confounding and complex internutrient relations are major challenges. An often-used approach is dietary pattern analyses, such as principal component analysis, to deal with internutrient correlations, and to more closely resemble the true way nutrients are consumed. However, despite these improvements, these approaches still require subjective decisions in the preselection of food groups. Moreover, they do not make efficient use of multivariate dietary data, because they detect only marginal associations. We propose the use of copula graphical models (CGMs) to model and make statistical inferences regarding complex associations among variables in multivariate data, where associations between all variables can be learned simultaneously.

OBJECTIVE

We aimed to reconstruct nutritional intake and physical functioning networks in Dutch older adults by applying a CGM.

METHODS

We addressed this issue by uncovering the pairwise associations between variables while correcting for the effect of remaining variables. More specifically, we used a CGM to infer the precision matrix, which contains all the conditional independence relations between nodes in the graph. The nonzero elements of the precision matrix indicate the presence of a direct association. We applied this method to reconstruct nutrient-physical functioning networks from the combined data of 4 studies (Nu-Age, ProMuscle, ProMO, and V-Fit, total n = 662, mean ± SD age = 75 ± 7 y). The method was implemented in the R package nutriNetwork which is freely available at https://cran.r-project.org/web/packages/nutriNetwork.

RESULTS

Greater intakes of vegetable protein and vitamin B-6 were partially correlated with higher scores on the total Short Physical Performance Battery (SPPB) and the chair rise test. Greater intakes of vitamin B-12 and folate were partially correlated with higher scores on the chair rise test and the total SPPB, respectively.

CONCLUSIONS

We determined that vegetable protein, vitamin B-6, folate, and vitamin B-12 intakes are partially correlated with improved functional outcome measurements in Dutch older adults.

The Role of Nutrition in Attenuating Age-Related Skeletal Muscle Atrophy

The elderly population is increasing rapidly worldwide, and we are faced with the significant challenge for maintaining or improving physical activity, independence, and quality of life. Sarcopenia, the age-related decline of skeletal muscle mass, is characterized by loss of muscle quantity and quality resulting to a gradual slowing of movement, a decrease in strength and power, elevated risk of fall-related injury, and often frailty. Supplemental, hormonal, and pharmacological approaches have been attempted to attenuate sarcopenia but these have not achieved outstanding results. In this review, we summarize the current knowledge of nutrition-based therapies for counteracting sarcopenia.

Higher dietary acid load potentially increases serum triglyceride and obesity prevalence in adults: An updated systematic review and meta-analysis

Background

In the current meta-analysis, we aimed to systematically review and summarize the eligible studies evaluating the association between dietary acid load in terms of potential renal acid load (PRAL) and net-endogenous acid production (NEAP) with anthropometric parameters and serum lipids in adult population.

Methods

In a systematic search from PubMed, Scopus, Web of Sciences and Cochrane electronic databases up to December 2018, relevant studies were included. Cross-sectional, case control or cohort studies evaluating the association between PRAL and NEAP with the mean values of body mass index (BMI), waist circumference (WC), low and high density lipoprotein cholesterol (LDL, HDL), triglyceride (TG), total cholesterol (TC) and the prevalence of obesity were included.

Results

According to our results, having higher dietary acid load content in terms of high PRAL scores was associated with higher triglyceride concentrations (weighted mean difference (WMD): 3.468; confidence interval (CI): -0.231, 7.166, P = 0.04) and higher obesity prevalence (30% and 27% in highest versus lowest categories). Accordingly, being in the highest category of NEAP was associated with higher prevalence of obesity (25% and 22% in highest versus lowest category). In subgroup analysis, higher PRAL scores was associated with higher BMI in women (WMD: 0.122; CI: -0.001, 0.245; P = 0.049) and higher NEAP in men (WMD: 0.890; CI: 0.430, 1.350; P < 0.001). There was no association between dietary acid load and other studied parameters.

Conclusions

In the current meta-analysis, high dietary acid load content was associated with higher serum triglyceride concentrations and higher obesity prevalence. Reducing dietary acid load content might be a useful preventive strategy against obesity and metabolic disorders.

Strategies for optimising musculoskeletal health in the 21st century

We live in a world with an ever-increasing ageing population. Studying healthy ageing and reducing the socioeconomic impact of age-related diseases is a key research priority for the industrialised and developing countries, along with a better mechanistic understanding of the physiology and pathophysiology of ageing that occurs in a number of age-related musculoskeletal disorders. Arthritis and musculoskeletal disorders constitute a major cause of disability and morbidity globally and result in enormous costs for our health and social-care systems.By gaining a better understanding of healthy musculoskeletal ageing and the risk factors associated with premature ageing and senescence, we can provide better care and develop new and better-targeted therapies for common musculoskeletal disorders. This review is the outcome of a two-day multidisciplinary, international workshop sponsored by the Institute of Advanced Studies entitled "Musculoskeletal Health in the 21st Century" and held at the University of Surrey from 30th June-1st July 2015.The aim of this narrative review is to summarise current knowledge of musculoskeletal health, ageing and disease and highlight strategies for prevention and reducing the impact of common musculoskeletal diseases.

Dietary Patterns, Skeletal Muscle Health, and Sarcopenia in Older Adults

In recent decades, the significance of diet and dietary patterns (DPs) for skeletal muscle health has been gaining attention in ageing and nutritional research. Sarcopenia, a muscle disease characterised by low muscle strength, mass, and function is associated with an increased risk of functional decline, frailty, hospitalization, and death. The prevalence of sarcopenia increases with age and leads to high personal, social, and economic costs. Finding adequate nutritional measures to maintain muscle health, preserve function, and independence for the growing population of older adults would have important scientific and societal implications. Two main approaches have been employed to study the role of diet/DPs as a modifiable lifestyle factor in sarcopenia. An a priori or hypothesis-driven approach examines the adherence to pre-defined dietary indices such as the Mediterranean diet (MED) and Healthy Eating Index (HEI)—measures of diet quality—in relation to muscle health outcomes. A posteriori or data-driven approaches have used statistical tools—dimension reduction methods or clustering—to study DP-muscle health relationships. Both approaches recognise the importance of the whole diet and potential cumulative, synergistic, and antagonistic effects of foods and nutrients on ageing muscle. In this review, we have aimed to (i) summarise nutritional epidemiology evidence from four recent systematic reviews with updates from new primary studies about the role of DPs in muscle health, sarcopenia, and its components; (ii) hypothesise about the potential mechanisms of ‘myoprotective’ diets, with the MED as an example, and (iii) discuss the challenges facing nutritional epidemiology to produce the higher level evidence needed to understand the relationships between whole diets and healthy muscle ageing.

Association of Fruit and Vegetable Intake and Frailty among Chinese Elders: A Cross-Sectional Study in Three Cities

OBJECTIVES

To examine the association of FVI and frailty in Chinese elders.

DESIGN

A sectional study was conducted in three cities (Shanghai, Zhengzhou, and Baoji) in China from June 2017 to June 2018.

PARTICIPANTS

A total of 5699 participants from 49 districts were included in the current study by two-stage sampling methods.

MEASUREMENTS

Frailty was measured by a validated Chinese version of the FRAIL scale. FVI per day was measured by two single questions.

RESULTS

The sample proportion with sufficient fruit intake was 36.7%, and 44.7% reported sufficient vegetable intake. The sample proportions that were robust, pre-frail, and frail were 43.6%, 38.3%, and 18.1%, respectively. Compared with low FVI, after including covariates, the odds ratio (OR) of frailty was 0.84 (95% CI: 0.73-0.97) for moderate fruit intake and 0.81 (95% CI: 0.70-0.94) for enough fruit intake; the OR of frailty was 0.83 (95% CI: 0.68-0.91) for moderate vegetable intake and 0.77 (95% CI: 0.64-0.93) for enough vegetable intake.

CONCLUSION

High FVI was negatively associated with the OR of frailty in Chinese elders. This finding implies it is important to promote FVI among adults to prevent frailty.

Vegetable and fruit intake and injurious falls risk in older women: a prospective cohort study

The role of vegetable and fruit intake in reducing falls risk in elderly populations is uncertain. This study examined the associations of vegetable and fruit intake with falls-related hospitalisations in a prospective cohort study of elderly women (n 1429, ≥70 years), including effects on muscular function, which represented a potential causal pathway. Muscular function, measured using grip strength and timed-up-and-go (TUG), and vegetable and fruit intake, quantified using a validated FFQ, were assessed at baseline (1998). Incident falls-related hospitalisation over 14·5-year follow-up was captured by the Hospital Morbidity Data Collection, linked via the Western Australian Data Linkage System. Falls-related hospitalisation occurred in 568 (39·7 %) of women. In multivariable-adjusted models, falls-related hospitalisations were lower in participants consuming more vegetables (hazard ratio (HR) per 75 g serve: 0·90 (95 % CI 0·82, 0·99)), but not fruit intake (per 150 g serve: 1·03 (95 % CI 0·93, 1·14)). Only total cruciferous vegetable intake was inversely associated with falls-related hospitalisation (HR: per 20 g serve: 0·90 (95 % CI 0·83, 0·97)). Higher total vegetable intake was associated with lower odds for poor grip strength (OR: 0·87 (95 % CI 0·77, 0·97)) and slow TUG (OR: 0·88 (95 % CI 0·78, 0·99)). Including grip strength and TUG in the multivariable-adjusted model attenuated the association between total vegetable intake and falls-related hospitalisations. In conclusion, elderly women with higher total and cruciferous vegetable intake had lower injurious falls risk, which may be explained in a large part by better physical function. Falls reduction may be considered an additional benefit of higher vegetable intake in older women.

Pilot Study Examining the Influence of Potassium Bicarbonate Supplementation on Nitrogen Balance and Whole-Body Ammonia and Urea Turnover Following Short-Term Energy Restriction in Older Men

With aging there is a chronic low-grade metabolic-acidosis that may exacerbate negative protein balance during weight loss. The objective of this randomized pilot study was to assess the impact of 90 mmol∙day⁻¹ potassium bicarbonate (KHCO₃) versus a placebo (PLA) on 24-h urinary net acid excretion (NAE), nitrogen balance (NBAL), and whole-body ammonia and urea turnover following short-term diet-induced weight loss. Sixteen (KHCO₃; n = 8, PLA; n = 8) older (64 ± 4 years) overweight (BMI: 28.5 ± 2.1 kg∙day⁻¹) men completed a 35-day controlled feeding study, with a 7-day weight-maintenance phase followed by a 28-day 30% energy-restriction phase. KHCO₃ or PLA supplementation began during energy restriction. NAE, NBAL, and whole-body ammonia and urea turnover (¹⁵N-glycine) were measured at the end of the weight-maintenance and energy-restriction phases. Following energy restriction, NAE was −9.8 ± 27.8 mmol∙day⁻¹ in KHCO₃ and 43.9 ± 27.8 mmol∙day⁻¹ in PLA (p < 0.05). No significant group or time differences were observed in NBAL or ammonia and urea turnover. Ammonia synthesis and breakdown tended (p = 0.09) to be higher in KHCO₃ vs. PLA following energy restriction, and NAE was inversely associated (r = −0.522; p < 0.05) with urea synthesis in all subjects. This pilot study suggests some benefit may exist with KHCO₃ supplementation following energy restriction as lower NAE indicated higher urea synthesis.

Alkalinization with potassium bicarbonate improves glutathione status and protein kinetics in young volunteers during 21-day bed rest

BACKGROUND & AIMS

Physical inactivity is associated with lean body mass wasting, oxidative stress and pro-inflammatory changes of cell membrane lipids. Alkalinization may potentially counteract these alterations. We evaluated the effects of potassium bicarbonate supplementation on protein kinetics, glutathione status and pro- and anti-inflammatory polyunsaturated fatty acids (PUFA) in erythrocyte membranes in humans, during experimental bed rest.

METHODS

Healthy, young, male volunteers were investigated at the end of two 21-day bed rest periods, one with, and the other without, daily potassium bicarbonate supplementation (90 mmol × d^-1), according to a cross-over design. Oxidative stress in erythrocytes was evaluated by determining the ratio between reduced (GSH) and oxidized glutathione (GSSG). Glutathione turnover and phenylalanine kinetics, a marker of whole body protein metabolism, were determined by stable isotope infusions. Erythrocyte membranes PUFA composition was analyzed by gas-chromatography.

RESULTS

At the end of the two study periods, urinary pH was 10 ± 3% greater in subjects receiving potassium bicarbonate supplementation (7.23 ± 0.15 vs. 6.68 ± 0.11, p < 0.001). Alkalinization increased total glutathione concentrations by 5 ± 2% (p < 0.05) and decreased its rate of clearance by 38 ± 13% (p < 0.05), without significantly changing GSH-to-GSSG ratio. After alkalinization, net protein balance in the postabsorptive state improved significantly by 17 ± 5% (p < 0.05) as well as the sum of n-3 PUFA and the n-3-to-n-6 PUFA ratio in erythrocyte membranes (p < 0.05).

CONCLUSIONS

Alkalinization during long-term inactivity is associated with improved glutathione status, anti-inflammatory lipid pattern in cell membranes and reduction in protein catabolism at whole body level. This study suggests that, in clinical conditions characterized by inactivity, oxidative stress and inflammation, alkalinization could be a useful adjuvant therapeutic strategy.

[Dietary acid load: A novel target for the nephrologist?]

The acid production of endogenous origin depends mainly on the metabolism of the food and varies with the nature of these. Of the order of 1mEq/kg/day for contemporary food in industrialized countries, it is reduced by more than one third among vegetarians and close to neutrality among vegans. The dietary acid load is eliminated by the normal kidneys, thus maintaining the acid-base equilibrium. In the setting of CKD, it will overflow the capacities of the nephrons, generating a retention of H+ ions, promoting subclinical acidosis. This tissue retention of H+ ions was confirmed by direct techniques in animal models and indirect techniques in humans. The systemic retention of H+ ions and the accompanying compensatory mechanisms have negative consequences on bone tissue, skeletal muscle, cardiovascular risk and renal function. In the animal, the substitution of casein (acid) by soy (alkaline) prevents metabolic acidosis and slows the progression of renal insufficiency. In man, various prospective studies have confirmed that the risk of renal insufficiency was positively correlated with the dietary acid load. Conversely, bicarbonate supplementation and/or a diet enriched with fruits and vegetables, have a favorable effect on renal insufficiency, including in subjects with normal bicarbonate. These results lead to reconsider the K/DOQI recommendations to correct acidosis when the bicarbonate level falls below 22mEq/L, since tissue retention of H+ ions and its negative consequences appear at higher or even normal levels of bicarbonates.

Gender-specific association between dietary acid load and total lean body mass and its dependency on protein intake in seniors

Diet-related mild metabolic acidosis may play a role in the development of sarcopenia. We investigated the relationship between dietary acid load and total lean body mass in male and female seniors age ≥ 60 years. We found that a more alkaline diet was associated with a higher %TLM only among senior women.

INTRODUCTION

The aim of this study was to determine if dietary acid load is associated with total lean body mass in male and female seniors age ≥ 60 years.

METHODS

We investigated 243 seniors (mean age 70.3 ± 6.3; 53% women) age ≥ 60 years who participated in the baseline assessment of a clinical trial on vitamin D treatment and rehabilitation after unilateral knee replacement due to severe knee osteoarthritis. The potential renal acid load (PRAL) was assessed based on individual nutrient intakes derived from a food frequency questionnaire. Body composition including percentage of total lean body mass (%TLM) was determined using dual-energy X-ray absorptiometry. Cross-sectional analyses were performed for men and women separately using multivariable regression models controlling for age, physical activity, smoking status, protein intake (g/kg BW per day), energy intake (kcal), and serum 25-hydroxyvitamin D concentration. We included a pre-defined subgroup analysis by protein intake (< 1 g/kg BW day, > 1 g/kg BW day) and by age group (< 70 years, ≥ 70 years).

RESULTS

Adjusted %TLM decreased significantly across PRAL quartiles only among women (P _trend = 0.004). Moreover, in subgroup analysis, the negative association between the PRAL and %TLM was most pronounced among women with low protein intake (< 1 g/kg BW per day) and age below 70 years (P = 0.002). Among men, there was no association between the PRAL and %TLM.

CONCLUSION

The association between dietary acid load and %TLM seems to be gender-specific, with a negative impact on total lean mass only among senior women. Therefore, an alkaline diet may be beneficial for preserving total lean mass in senior women, especially in those with low protein intake.

Increasing alkali supplementation decreases urinary nitrogen excretion when adjusted for same day nitrogen intake

We examined whether escalating doses of potassium bicarbonate (KHCO₃) supplements alter urinary nitrogen excretion expressed as a ratio to same day nitrogen intake (measure of muscle-protein breakdown). The ratio declined significantly from placebo to low to high dose of KHCO₃ supplementation in older adults over 3 months, suggesting muscle-sparing.

INTRODUCTION

Neutralization of dietary acid load with alkali supplementation (i.e., KHCO₃) has been hypothesized to have muscle protein-sparing effects. In controlled feeding studies with fixed nitrogen (N) intake/day, 24-h urinary N excretion is a good marker of muscle breakdown. However, in studies with self-selected diets, changes in 24-h urinary N excretion can be influenced by shifts in N intake.

METHODS

We evaluated changes in 24-h total urinary N excretion as a ratio of N excretion to concurrent N intake in 233 older men and women who participated in an 84-day KHCO₃ supplementation randomized placebo-controlled trial.

RESULTS

After adjustment for relevant cofactors, escalating doses of KHCO₃ (1 mmol/kg/day [low] or 1.5 mmol/kg/day [high]) resulted in a progressive decline in urinary N excretion/N intake compared to placebo (overall P for trend = 0.042). The 84-day change in urinary N excretion/N intake in the high-dose KHCO₃ group was statistically significantly lower compared to placebo (P = 0.012) but not compared to the low-dose KHCO₃ group (P = 0.276). The 84-day change in urinary N excretion/N intake in the low-dose KHCO₃ group did not differ significantly from placebo (P = 0.145).

CONCLUSIONS

Urinary N excretion expressed as ratio to same day N intake declined steadily with increasing doses of KHCO₃ supplementation from low 1 mmol/kg/day to high 1.5 mmol/kg/day, suggesting a nitrogen-sparing effect. Compared to urinary N excretion alone, this ratio could be a more reasonable measure of muscle protein metabolism in large-scale long-term human studies.

TRIAL REGISTRATION

Clinicaltrials.gov NCT1475214.

Relationship between major dietary patterns and sarcopenia among menopausal women

BACKGROUND AND AIM

Dietary habits have been associated with the prevalence of the sarcopenia and limited data are available in this field for menopausal women. This study focused on the relationship between dietary patterns and prevalence of the sarcopenia in menopausal women.

METHODS

This cross-sectional study was done in 250 menopausal women 45 years old or older. Dietary data were collected using a food-frequency questionnaire and physical activity was assessed by International Physical Activity Questionnaire (IPAQ). Height, weight, skeletal muscle mass, hand grip, and gait speed were measured and sarcopenia was defined based on European Working Group on Sarcopenia in Older People (EWGSOP) guidelines.

RESULTS

Using factor analysis, two major dietary patterns were found: a Western pattern (high in commercial beverage, sugar and dessert, snacks, solid fat, potato, high fat dairy, legume, organ meat, fast food, and sweets) and a Mediterranean pattern (high in olive, low-fat dairy, vegetable, fish, nut, and vegetable oil). After adjusting for confounding variables, for the highest vs the lowest tertiles, the Odds Ratio (OR) for sarcopenia was 1.06 [95% confidence interval (CI), 0.47-2.37] in the Western pattern and 0.40 [95% confidence interval (CI), 0.17-0.89] in the Mediterranean pattern.

CONCLUSIONS

Our findings suggest that Mediterranean dietary pattern has a favorable role in the prevention of sarcopenia.

Does nutrition play a role in the prevention and management of sarcopenia?

There is a growing body of evidence that links nutrition to muscle mass, strength and function in older adults, suggesting that it has an important role to play both in the prevention and management of sarcopenia. This review summarises the discussions of a working group [ESCEO working group meeting 8th September 2016] that met to review current evidence and to consider its implications for preventive and treatment strategies. The review points to the importance of 'healthier' dietary patterns that are adequate in quality in older age, to ensure sufficient intakes of protein, vitamin D, antioxidant nutrients and long-chain polyunsaturated fatty acids. In particular, there is substantial evidence to support the roles of dietary protein and physical activity as key anabolic stimuli for muscle protein synthesis. However, much of the evidence is observational and from high-income countries. Further high-quality trials, particularly from more diverse populations, are needed to enable an understanding of dose and duration effects of individual nutrients on function, to elucidate mechanistic links, and to define optimal profiles and patterns of nutrient intake for older adults.

Dietary acid load and renal function have varying effects on blood acid-base status and exercise performance across age and sex

Diet composition influences acid-base status of the body. This may become more relevant as renal functional capacity declines with aging. We examined the effects of low (LD) versus high dietary acid load (HD) on blood acid-base status and exercise performance. Participants included 22 adolescents, 33 young adults (YA), and 33 elderly (EL), who followed a 7-day LD and HD in a randomized order. At the end of both diet periods the subjects performed a cycle ergometer test (3 × 10 min at 35%, 55%, 75%, and (except EL) until exhaustion at 100% of maximal oxygen uptake). At the beginning of and after the diet periods, blood samples were collected at rest and after all workloads. Oxygen uptake, respiratory exchange ratio (RER), and heart rate (HR) were monitored during cycling. In YA and EL, bicarbonate (HCO₃^-) and base excess (BE) decreased over the HD period, and HCO₃^-, BE, and pH were lower at rest after HD compared with LD. In YA and EL women, HCO₃^- and BE were lower at submaximal workloads after HD compared with LD. In YA women, the maximal workload was 19% shorter and maximal oxygen uptake, RER, and HR were lower after HD compared with LD. Our data uniquely suggests that better renal function is associated with higher availability of bases, which may diminish exercise-induced acidosis and improve maximal aerobic performance. Differences in glomerular filtration rate between the subject groups likely explains the larger effects of dietary acid load in the elderly compared with younger subjects and in women compared with men.

[Common therapeutic approaches of sarcopenia in the elderly and uremic myopathy]

The gradual loss of weight and function of muscle in patients with chronic kidney disease as in the elderly impacts the quality of life. Early management should help slow the functional limitation. Physical activity is the first therapy to propose that ensures stability of muscle mass and improved function. Resistance training programs have proven effective but are not yet widely available in nephrology units. The nutritional management should not be forgotten because there is a resistance to anabolism and protein intake should be involved in physical activity program. Associated treatments should not be neglected: vitamin D, anti-inflammatory, androgens. Some are still under evaluation. Therapeutic option, tomorrow, could be anti-myostatin antibodies and glitazones.

Diet-Induced Low-Grade Metabolic Acidosis and Clinical Outcomes: A Review

Low-grade metabolic acidosis is a condition characterized by a slight decrease in blood pH, within the range considered normal, and feeding is one of the main factors that may influence the occurrence of such a condition. The excessive consumption of acid precursor foods (sources of phosphorus and proteins), to the detriment of those precursors of bases (sources of potassium, calcium, and magnesium), leads to acid-base balance volubility. If this condition occurs in a prolonged, chronic way, low-grade metabolic acidosis can become significant and predispose to metabolic imbalances such as kidney stone formation, increased bone resorption, reduced bone mineral density, and the loss of muscle mass, as well as the increased risk of chronic diseases such as type 2 diabetes mellitus, hypertension, and non-alcoholic hepatic steatosis. Considering the increase in the number of studies investigating the influence of diet-induced metabolic acidosis on clinical outcomes, this review gathers the available evidence evaluating the association of this disturbance and metabolic imbalances, as well as related mechanisms. It is necessary to look at the western dietary pattern of most countries and the increasing incidence of non-comunicable diseases for the balance between fruit and vegetable intake and the appropriate supply of protein, mainly from animal sources, so that it does not exceed the daily recommendations.