Table 2.

Studies on nuts and sarcopenia related factors.

Author (Year) Study Location	Study Design	Study Participants	Dietary Assessment Method	Nuts/Dietary Patterns Assessed	Measure of Functional or Related Outcomes	Results
Nut-specific studies
Arias-Fernández, 2019 (Spain)	Prospective study: Seniors-ENRICA cohort Cohort was established in 2008–2010, with 7.2 years of follow-up	3289 individuals aged ≥60 years	A validated computerised diet history was used to assess nut consumption in 2008–2010 and 2012. Average nut consumption at baseline (2008–2010) and in the first follow-up wave of data collection (2012) was calculated to represent cumulative intake over follow-up.	Diet history included 20 types of nuts, which were grouped as follows: almonds, hazelnuts, peanuts, chestnuts, walnuts, pine nuts, sunflower seeds, pistachios, sesame seeds, cashews, macadamia nuts, and other types of nuts.	Five domains were considered to characterise participants’ physical function: (1) Agility: Rosow and Breslau scale (self-reported) (n = 1502) (2) Mobility: Rosow and Breslau scale (self-reported) (n = 1502) (3) Overall physical function: physical component summary (PCS) score of the 12-Item Short-Form Health Survey SF-12 (self-reported) (n = 1665) (4) Grip strength: highest value in two consecutive measures on the dominant hand (objective measure of muscle strength) (n = 1256) (5) Gait speed: 3 m walking speed test (objective measure of physical performance) (n = 1233)	In men, compared with no consumption, an intake of nuts ≥11.5 g/d (median) in nut consumers was associated with lower risk of self-reported impaired agility (fully-adjusted HR = 0.59, 95% CI: 0.39–0.90) and mobility (fully-adjusted HR = 0.50, 95% CI: 0.28–0.90). In women, compared with no consumption, the fully-adjusted HR (95% CI) of impaired self-reported overall physical function was 0.65 (0.48–0.87) for intake ≥11.5 g/d. No association was found between nut consumption and grip strength and gait speed.
Studies on dietary patterns that include nuts (as a food group)
Bradlee, 2018 (United States)	Prospective study: Framingham Offspring Study Began in 1972, with a median follow-up of 13.0 years	5124 offspring were enrolled in 1972 For skeletal muscle mass outcomes, participants aged 40 years or older were included. For functional status outcomes, participants aged 50 years or older at the time of the dietary assessments were included; follow-up for functional status outcomes continued for up to 16 years.	Diet records (six days)	Protein-source foods: Legumes, Soy, Nuts, Seeds	Skeletal muscle mass was estimated using BIA. Functional status was measured using standardised instruments: (1) Rosow–Breslau scale measures gross-mobility capacity (2) Nagi scale assesses self-reported functional limitations	Higher intake of “legumes, soy, nuts and seeds” was associated with higher percent skeletal muscle mass over 9 years. In men, compared with consumption <0.25 serving/day of legumes, soy, nuts and seeds, those who consumed ≥1.25 serving/day had higher percent skeletal muscle mass (36.8% vs. 37.5%, p = 0.0197). In women, compared with consumption <0.25 serving/day of legumes, soy, nuts and seeds (27.3%), those who consumed 0.25 to <1.25 serving/day and ≥1.25 serving/day had higher percent skeletal muscle mass (28.2% and 28.1% respectively, both p ≤ 0.0156). In the multivariable Cox proportional hazards models, “legumes, soy, nuts and seeds” was not a predictor of limitation in two or more functional tasks from the Rosow–Breslau and Nagi scales (HR = 0.96, 95% CI: 0.72, 1.30).
Hai, 2017 (China)	Cross-sectional study	848 individuals aged ≥60 years who lived in the community for more than 12 months. Data from 834 participants were used for the analysis.	A validated simplified FFQ was used. Frequency units: day, week, month or never.	Nine food categories based on the Chinese Food Guide Pagoda: (1) Grain or cereals (2) Vegetables (3) Fruit (4) Meat (pork, beef, poultry, and mutton) (5) Eggs (6) Fish and shrimp (7) Milk and milk products (8) Legumes (9) Nuts	Sarcopenia, i.e., presence of low muscle mass, plus low muscle strength or low physical performance. Muscle mass was measured using BIA. Grip strength was measured using a dynamometer. Usual gait speed (m/s) on a 6 m course was used to measure physical performance and a slow walking speed was defined as a walking speed <0.8 m/s.	In females, participants with sarcopenia had significantly lower frequency of nut consumption than those without sarcopenia (0.05 times vs. 0.81 times per week, p = 0.022). This was not found in male participants (p = 0.135). After adjusting for potential confounders, there was a significant association between prevalence of sarcopenia and frequency of nut consumption per week (OR = 0.724, 95% CI: 0.532, 0.985, p < 0.05).
Lim, 2020 (Korea)	Cross-sectional study. 2008 to 2011 Korea National Health and Nutrition Examination Survey (KNHANES).	3350 elderly over 65 years, 862 had sarcopenia.	24 h dietary intake	Food intake analysis was based on the guideline of 15 food groups: (1) Cereals (2) Potato and starches (3) Sugars and sweeteners (4) Pulses (5) Nuts and seeds (6) Vegetables (7) Fungi and mushrooms (8) Fruits (9) Meat (10) Eggs (11) Fish and shellfish (12) Seaweeds (13) Milk (14) Oil and fat (15) Beverages	Sarcopenia was defined as muscle mass excluding bones and fats of limbs measured by dual energy X-ray absorptiometry divided by weight in the form of percent is under the twice of standard deviation.	In males, the sarcopenia group had significantly lower intake of nuts and seeds than the non-sarcopenia group (5.2 g/day vs. 3.1 g/day, p = 0.002). This was not found in female participants (p = 0.258). Logistic regression analyses showed no significant association between prevalence of sarcopenia and tertiles of nut and seed intake in both males and females.
Studies on dietary patterns that include nuts (diet quality indices)
Ballesteros, 2020 (Spain)	Prospective study: Seniors-ENRICA cohort Cohort was established in 2008–2010, with a median follow-up of 3.5 years	3289 individuals aged ≥60 years 2071 included in the analysis	A validated computer-assisted face-to-face dietary history.	Mediterranean Diet Adherence Screener (MEDAS) score was used to determine the adherence to the Mediterranean diet, with a higher score indicating greater adherence.	Risk of falling	There was an inverse dose-response relationship between the MEDAS score and the risk of falling in older adults (p for trend = 0.04). Compared with the people in the lowest tertile of the MEDAS score, those in the second tertile (OR = 0.93, 95% CI: 0.71–1.21) and highest tertile (OR = 0.72, 95% CI: 0.53–0.98) showed lower risk of falling after adjustment for potential confounders.
Schacht, 2019 (Denmark)	Cross-sectional study	184 Danish older individuals aged 65 years and above participated in the “Counteracting Age-related Loss of Skeletal Muscle Mass” (CALM) study.	3 days weighed food diaries from Wednesday to Friday. Average daily consumption of different food products was calculated.	Dietary index characterised by higher intakes of whole grains, dairy products, fish, legumes, nuts, fruit, and vegetables.	Muscle function (1) 30s chair stands (2) 400 m gait speed (3) Handgrip strength (dynamometer DHD-1 [SH100]) (4) Knee extensor maximal voluntary contractions was measured using an isokinetic dynamometer	Dietary index was associated with faster 400 m walking speed (p for trend = 0.021). No associations were found between dietary index and 30s chair stands, handgrip strength, knee extensor maximal voluntary contractions (all p for trend > 0.05).
Hashemi, 2015 (Iran)	Cross-sectional study	300 elderly men and women aged 55 years and older	Semi-quantitative Food Frequency Questionnaire, frequency of 117 common Iranian food items by standard serving size	Mediterranean pattern was defined as a dietary pattern with high factor loadings (>0.4) in food groups such as olives and olive oil, low and high carotenoid vegetables, tomatoes, whole grains, nuts, fish, fresh and dried fruits, and pickles.	Sarcopenia is defined as low appendicular muscle mass with either low muscle strength or low muscle performance. Muscle mass (DXA) was calculated as the ratio of total lean mass of legs and arms (ASM) to squared height. Muscle strength was measured using a handgrip dynamometer. Muscle performance was measured using a 4 m walk gait speed test. Low muscle performance was defined as gait speed <0.8 m/s.	There was a significant association between Mediterranean dietary pattern and prevalence of low gait speed (p = 0.02). The percentage of participants with low gait speed (< 0.8 m/s) in the top tertile was 29.3%, second tertile was 47.5%, and lowest tertile was 43.9%. After adjusting for potential confounders, Mediterranean diet was associated with lower odds of having sarcopenia. Odds ratio (95% CI): T1: 1.00 T2: 0.84 (0.40–1.70) T3: 0.40 (0.17–0.97) P for trend: 0.04