Data extraction table: characteristics of observational studies (prospective cohorts & cross-sectional, n = 7).
| Authors (Year); Country | Study design | Cohort description & size (n) | Exposure definition/Measurement | Follow-up duration | Main finding & adjusted risk estimates (95% CI) | Confounders adjusted in model |
|---|---|---|---|---|---|---|
| Prospective cohorts | ||||||
| Wang et al. (2023);United States [13] | Prospective cohort | NHS, non-frail women ≥ 60 y, n = 71,704 | Nut consumption1 via FFQ & frailty via FRAIL in aging females | FFQ: every 4 y from 1990–2014, FRAIL: every 4 y from 1992–2016 | ↓ Risk of frailty: 5 srvngs/week HR 0.70 (0.64, 0.76) vs. < 1 srvngs/mo group. Peanuts, PB, walnuts: ↓ risk of frailty vs. < 1 serving/mo, adj HRs: 2 srvngs/week peanuts & walnuts = 0.84 (0.74, 0.94) and 0.85 (0.75, 0.97) | Age, calendar periods, smoking, BMI, EI, AHEI-2010 score, medication use, PAL |
| Prospective cohorts | ||||||
| Wild et al. (2024);Australia [14] | Prospective cohort | ASPREE, ≥ 70 y, n = 9,916 | Nut consumption2 via FFQ and DFS3 | 3.9 y | Risk of DFS endpoint 23% ↓ (HR 0.77 [0.61–0.98]) in daily nut consumers vs. no/infrequent nut intake. 2nd quartile nut intake = significant association for healthy lifespan & 29% ↓ risk of DFS endpoint (HR 0.71 [0.51–0.98], P = 0.037) | Age, sex, IRSAD quintile and education, physical capacity, smoking status and alcohol consumption, WC, hypertension, T2DM, depression score, frailty status, self-reported oral health status and dietary quality score |
| Cross-sectional | ||||||
| Feyesa et al. (2025);United States [15] | Cross-sectional | NHANES (2003–2012) | n = 5,807, ≥ 60 y (53.4% F) | Nut consumption4 ia AMPM & functional limitation/severity via PFQ & HRQOL via HRQOL-4 | Nut intake ≥ 6.9 g/day = fewer functional limitations, significant ↓ severity of functional limitation score vs. non-consumers. 19 % ↓ odds of poor physical health, 28% ↓ odds of activity limitations vs. non-consumers | Functional limitations (P = 0.048), ↓ severity of limitations (P = 0.004) & better QOL (OR = 0.81; 95% CI: 0.68, 0.98; P = 0.027, & activity limitations, OR = 0.72; 95% CI: 0.55, 0.95; P = 0.023) |
| Garrido-Miguel et al. (2021);Spain [30] | Cross-sectional | First-year university students, University of Castilla La Mancha, Spain | n = 354, 18–30 y | Frequency of nut consumption5 via FFQ & WC, BMI, %BF, FFM, CRF via PFT, MS via MSI | Nut intake ≥ 5/week = CRF & MSI vs. < 1/week & ↓ WC/height, %BF, but when adjusted for CRF, MSI significance disappeared for WC/height & FFM | Not reported |
| Cross-sectional | ||||||
| Mazumdar et al. (2025);Bangladesh [33] | Cross-sectional | Physically fit adults, face-to-face interview in Southern Bangladesh | n = 959, 18–40 y | Functional food intake (nut category focus5 via survey & self-reported GI & musculoskeletal diseases | Functional food intake associated w/ ↓ risk of GI & musculoskeletal diseases in adults | Nuts weekly OR = 0.59, 95% CI 0.36–0.97; P 0.037 |
| Jun and Shin (2024);South Korea [31] | Cross-sectional | KNHANES VII (2016–2018) | n = 14,844, 19–65+ y | Nut consumption6 (in-person 24-h dietary recall) & low MS via MSI | Older M consumers had 45% ↓ risk & older female consumers had 31% ↓ risk vs. non-consumers | Older male consumers: (OR = 0.55; 95% CI [0.38, 0.79]), older female consumers: (OR = 0.69; 95% CI [0.51, 0.93]) |
| Xu et al. (2025);China [16] | Cross-sectional | CLHLS (2018), face-to-face interviews | n = 14,181, 84.86 ± 11.47 y (55.08% F) | Nut consumption7 and sarcopenia in Chinese older adults | Higher nut consumption = significantly ↓ odds of sarcopenia | OR = 0.62 (95% CI: 0.51, 0.77) |
↑: higher or increased; ↓: lower(ed) or reduced; AHEI-2010: dietary quality index; AMPM: Automated Multiple-Pass Method by U.S. Department of Agriculture, validated dietary recall tool; ASPREE: ASPirin in Reducing Events in the Elderly, longitudinal study; BMI: body mass index; CLHLS: Chinese Longitudinal Healthy Longevity Survey; CRF: Cardio-respiratory fitness; DFS: disability-free survival; EI: Energy intake; FFQ: Food-Frequency Questionnaire, validated tool for dietary recall; FRAIL: Measures Fatigue, Resistance, Ambulation, Illness, Loss of Weight, validated tool to assess frailty in older adults; HRQOL: health-related quality of life; HRQOL-4: Health-Related Quality of Life Questionnaire, validated tool endorsed by CDC, from NHANES Current Health Questionnaire; IRSAD: Index of Relative Socio-economic Advantage and Disadvantage; KNHANES: Korea National Health and Nutrition Examination Survey; MS: muscle strength; MSI: muscle strength index via TKK 5401 GripD digital adaptive grip dynamometer; NHANES: U.S. National Health and Nutrition Examination Survey; NHS: the Nurses’ Health Study; PAL: Physical activity level; PFQ: Physical Functioning Questionnaire by NHANES; PFT: physical fitness test via the Course Navette test; T2DM: type 2 diabetes mellitus. 1) Sum intake of peanuts, peanut butter (PB), walnuts, and other nuts. Separate analysis of peanuts, PB, and walnuts. 2) Type of nut not specified, interpreted as representing total nut intake. 3) Composite measure of survival w/out dementia or major physical disability and was assessed as the first event of death or onset of dementia or persistent loss of one of six basic ADLs or admission to a nursing care facility for physical disability if Katz ADL not administered. 4) Mean intake of almonds, almond butter, Brazil nuts, cashews, cashew butter, hazelnuts, macadamias, pecans, pine nuts, pistachios, walnuts, peanuts, peanut butter from two 24-h dietary recalls. 5) Total intake of nuts (type not specified) per day, week, month. 6) Hazelnuts, acorns, macadamia nuts, chestnuts, Brazil nuts, almonds, ginkgo nuts, pine nuts, cashew nuts, pecans, walnuts, and pistachio nuts) and peanuts. 7) Sum intake of peanuts, peanut butter, walnuts, and other nuts. Separate analysis of peanuts, peanut butter, and walnuts.