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

Sarcopenia is a geriatric syndrome characterized by the loss of skeletal muscle mass and strength and is linked to frailty, functional impairment, poor quality of life, and premature mortality. It has been recognized as a muscle disease with an ICD-10-CM code and imposes substantial healthcare costs. Prevalence varies widely depending on definitions used. Healthy eating is advocated for preserving health in later life, and the DASH eating plan emphasizes fruits, vegetables, low-fat dairy, whole grains, nuts, fish and poultry while limiting saturated fat, meats, sweets, and sugar-sweetened beverages. Although DASH adherence has been associated with reduced risk of cardiovascular disease, cancer, and type 2 diabetes, its relationship with sarcopenia has been scarcely studied. The study aimed to examine whether adherence to a DASH-style diet is associated with sarcopenia and its components (muscle mass, muscle strength, and physical performance) in community-dwelling older adults.

Prior evidence suggests DASH may influence pathways relevant to muscle health via anti-inflammatory, antioxidant, and insulin-sensitizing effects. Limited studies have examined DASH in relation to sarcopenia. One cross-sectional study reported better handgrip strength with higher diet quality (including DASH-like patterns), while an 8-week quasi-experimental intervention with modified DASH plus resistance training improved body composition and strength in overweight/obese older adults. However, prior work often assessed components (e.g., handgrip strength) rather than sarcopenia per se, and findings from interventions may not generalize to habitual intake. Other cohort and patient studies of patterns similar to DASH (e.g., Mediterranean-style or legume/vegetable/fruit-rich diets) showed no significant associations with sarcopenia, though populations and definitions varied.

Design and participants: Population-based cross-sectional study conducted May–October 2011 in Tehran, Iran (district 6). Cluster random sampling selected 300 adults aged ≥55 years (150 men, 150 women). Inclusion: age ≥55, ambulatory without assistive devices, no active cancer (self-report). Exclusion: susceptibility to sarcopenia due to artificial limbs/prosthesis or debilitating diseases (CHF, COPD, chronic renal failure, cirrhosis/liver failure) based on self-report. Ethics approval was obtained; informed consent collected; data gathered via trained interviewer home visits. Dietary assessment: A Block-format 117-item FFQ administered by trained nutritionists captured usual intake over the prior year with standard portion sizes and open-ended frequency responses (daily/weekly/monthly). Frequencies were converted to grams/day using household measures; seasonal availability for fruits/vegetables was accounted for. Nutrient intakes were computed using Nutritionist IV (USDA-modified database). FFQ validity in older adults was supported by a pilot study (n=30) with correlations vs four dietary records: animal protein r=0.43, fruits 0.57, vegetables 0.45; energy-adjusted β-carotene r=0.65, vitamin C r=0.76. DASH score: Eight components were used: higher intake of fruits; vegetables; nuts and legumes; low-fat dairy; whole grains; and lower intake of sodium; sugar-sweetened beverages and sweets; red and processed meats. Energy-adjusted intakes (residual method) were categorized into deciles. For beneficial components, decile 10=score 10 to decile 1=score 1; for adverse components scoring reversed. Component scores summed to total DASH score range 8–80. Sarcopenia assessment: Both EWGSOP1 and EWGSOP2 criteria applied. Muscle mass measured as appendicular skeletal muscle (ASM: arms+legs lean mass by DXA, Hologic Discovery) normalized by height squared (ASM/height²). EWGSOP1 low muscle mass cut-offs: <5.45 kg/m² (women), <7.26 kg/m² (men); updated cut-offs: <5.5 kg/m² (women), <7.0 kg/m² (men). Muscle strength measured by squeeze bulb dynamometer (Jamar Rolyan c7489-02), testing per ASHT positioning; three trials per hand, averages across both hands used. Low strength defined by sex- and age-specific cutoffs (Merkies et al.); EWGSOP thresholds noted (<30 kg men, <20 kg women; revised <27 kg men, <16 kg women). Physical performance measured by 4-m gait speed; <0.8 m/s classified as low performance. Other variables: Collected age, sex, socioeconomic status, medical history, medication use, smoking, alcohol. Physical activity assessed via IPAQ short form; MET-min/week computed and summed. Anthropometry included weight, height, BMI (kg/m²) and waist circumference. Statistical analysis: Participants categorized into tertiles of DASH score. Group comparisons used ANOVA and chi-square. Dietary intakes compared via ANCOVA adjusted for age, sex, energy. Associations between DASH (tertiles) and sarcopenia were examined using logistic regression: Model 1 adjusted for age, sex, energy intake; Model 2 further adjusted for physical activity (MET-h/week), smoking, alcohol use, medication use (statin, ACE inhibitors, estrogen, testosterone), corticosteroid use, and positive history of disease (asthma, arthritis, MI, CVA, diabetes). Trends tested by modeling tertile medians as ordinal variables. Linear regression assessed DASH score vs sarcopenia components. Analyses used SPSS v18; two-sided P<0.05 significant.

Sample characteristics: Mean age 66.7 ± 7.7 years; mean BMI 27.3 ± 4.2 kg/m². Using EWGSOP2, 31/300 participants met sarcopenia criteria. Those with sarcopenia had lower BMI and higher use of sex hormones and corticosteroids. Dietary patterns across DASH tertiles: Highest DASH tertile had higher intakes of dairy, fruits, vegetables, nuts/legumes/soy, fiber, protein, calcium, folate; and lower intakes of SSBs/sweets, red/processed meats, sodium, fat, and energy (most P<0.01). Prevalence across DASH tertiles: In the whole population, muscle mass (ASM/height²) and handgrip strength means were lower in the highest vs lowest DASH tertile (P=0.02 and P=0.005, respectively), but the prevalence of EWGSOP2 sarcopenia and other component prevalences did not differ significantly across tertiles. Primary association (EWGSOP2): No significant association between DASH tertiles and sarcopenia: crude OR for highest vs lowest tertile 1.08 (95% CI 0.45–2.54); adjusted OR 1.04 (0.39–2.75); P for trend 0.90. By sex: men adjusted OR 2.29 (0.39–13.29); women 0.75 (0.23–2.45), both non-significant. EWGSOP1 sensitivity analyses: Also null—crude OR highest vs lowest tertile 0.73 (0.36–1.47); adjusted OR 0.78 (0.36–1.67). By sex: men 1.22 (0.42–3.55); women 0.45 (0.14–1.44), all non-significant. Linear regression: Unadjusted DASH score inversely related to handgrip strength (β −0.044, 95% CI −0.083 to −0.006; P=0.02), but association became non-significant after multivariable adjustment. No significant associations with ASM/height² or gait speed. DASH components: After multivariable adjustment, highest vs lowest tertile of vegetables was associated with lower odds of EWGSOP2 sarcopenia (OR 0.24; 95% CI 0.07–0.74; P trend=0.01). No other component showed significant associations.

The study addressed whether adherence to a DASH-style dietary pattern is linked to sarcopenia risk in older adults. After extensive adjustment for confounders, no significant association was observed using either EWGSOP2 or EWGSOP1 criteria. This aligns with some prior studies evaluating other healthy dietary patterns that also found no association with sarcopenia, although differences in scoring systems and populations may influence results. A protective association of higher vegetable intake with lower sarcopenia odds suggests specific components of DASH might be beneficial, potentially through effects on inflammation, oxidative stress, metabolic acidosis, and insulin resistance—mechanisms implicated in muscle loss. Null findings may reflect limited statistical power due to the relatively low number of sarcopenia cases, potential measurement misclassification (e.g., handgrip instrument not the gold standard), and cross-sectional design precluding causal inference. Overall, results suggest that while overall DASH adherence was not associated with sarcopenia in this sample, aspects such as higher vegetable intake may relate to better muscle health.

In this community-based cross-sectional sample of Iranian adults aged ≥55 years, adherence to a DASH-style diet was not significantly associated with odds of sarcopenia after adjustment for confounders. A higher intake of vegetables, a DASH component, was associated with lower odds of sarcopenia. Future research should include larger, prospective cohort studies and trials with precise dietary and muscle assessments to clarify potential protective roles of specific DASH components and to establish temporality and causality.

Cross-sectional design prevents causal inference. Potential dietary measurement error and misclassification with FFQ, including imprecision for sodium intake; no 24-hour urine sodium collected. Handgrip strength measured by squeeze bulb dynamometer rather than Jamar gold standard, risking misclassification. Limited sample size and low number of sarcopenia cases reduced power and yielded wide confidence intervals. Study constrained to a specific Tehran district due to DXA availability (maximum 300 scans), limiting generalizability to the broader Iranian population. Limited data on musculoskeletal diseases (only arthritis captured) and no information on antipsychotic drugs. Relatively young older-adult sample (≥55 years) may have contributed to a lower sarcopenia prevalence.