The feasibility of a 6-month dietary intervention aiming to increase protein intake among community-dwelling older adults with low habitual protein intake: A secondary analysis of the PROMISS randomised controlled trial.

BACKGROUND: The PROMISS randomised controlled trial showed that personalised dietary advice increased protein intake and improved 400-m walk time and leg strength among community-dwelling older adults with a low habitual protein intake. This secondary analysis describes and further evaluates the methods and feasibility of the model used to carry out dietary intervention in the PROMISS randomised controlled trial. METHODS: In total, 185 participants (≥65 years, 54% women) with a habitual low protein intake (<1.0 g/kg adjusted body weight/day) in Finland and the Netherlands received personalised dietary advice and complimentary protein-enriched food products for 6 months with two main objectives: (1) to increase protein intake to ≥1.2 g/kg adjusted body weight/day (energy-neutral) and (2) to include each day a 'high-protein meal' containing ≥ 30-35 g of protein. The feasibility of the model was evaluated by the adoption of the advice, feedback from the participants, and practical experiences by the nutritionists. RESULTS: In all, 174 participants (93.5%) completed the intervention. At the 6-month follow-up, 41.8% reached both main objectives of the advice. The participants' general rating for the dietary advice was 8.6 (SD 1.0) (on a scale of 1-10; 10 indicating very good). Sticking to the advice was (very) easy for 79.2% of the participants. The nutritionists perceived the model feasible for the participants except for those with low food intake. CONCLUSIONS: The methods used in this model are mainly feasible, well-received and effective in increasing protein intake among community-dwelling older adults with low habitual protein intake.

The cost effectiveness of personalized dietary advice to increase protein intake in older adults with lower habitual protein intake: a randomized controlled trial.

PURPOSE: To examine the cost effectiveness of dietary advice to increase protein intake on 6-month change in physical functioning among older adults. METHODS: In this multicenter randomized controlled trial, 276 community-dwelling older adults with a habitual protein intake < 1.0 g/kg adjusted body weight (aBW)/d were randomly assigned to either Intervention 1; advice to increase protein intake to ≥ 1.2 g/kg aBW/d (PROT, n = 96), Intervention 2; similar advice and in addition advice to consume protein (en)rich(ed) foods within half an hour after usual physical activity (PROT + TIMING, n = 89), or continue the habitual diet with no advice (CON, n = 91). Primary outcome was 6-month change in 400-m walk time. Secondary outcomes were 6-month change in physical performance, leg extension strength, grip strength, body composition, self-reported mobility limitations and quality of life. We evaluated cost effectiveness from a societal perspective. RESULTS: Compared to CON, a positive effect on walk time was observed for PROT; - 12.4 s (95%CI, - 21.8 to - 2.9), and for PROT + TIMING; - 4.9 s (95%CI, - 14.5 to 4.7). Leg extension strength significantly increased in PROT (+ 32.6 N (95%CI, 10.6-54.5)) and PROT + TIMING (+ 24.3 N (95%CI, 0.2-48.5)) compared to CON. No significant intervention effects were observed for the other secondary outcomes. From a societal perspective, PROT was cost effective compared to CON. CONCLUSION: Dietary advice to increase protein intake to ≥ 1.2 g/kg aBW/d improved 400-m walk time and leg strength among older adults with a lower habitual protein intake. From a societal perspective, PROT was considered cost-effective compared to CON. These findings support the need for re-evaluating the protein RDA of 0.8 g/kg BW/d for older adults. TRIAL REGISTRATION: The trial has been registered at ClinicalTrials.gov (NCT03712306). Date of registration: October 2018. Registry name: The (Cost) Effectiveness of Increasing Protein Intake on Physical Functioning in Older Adults. Trial Identifier: NCT03712306.

Effectiveness of nutritional interventions in older adults at risk of malnutrition across different health care settings: Pooled analyses of individual participant data from nine randomized controlled trials.

BACKGROUND & AIMS: Protein-energy malnutrition is a health concern among older adults. Improving nutritional status by increasing energy and protein intake likely benefits health. We therefore aimed to investigate effects of nutritional interventions in older adults (at risk of malnutrition) on change in energy intake and body weight, and explore if the intervention effect was modified by study or participants' characteristics, analysing pooled individual participant data. METHODS: We searched for RCTs investigating the effect of dietary counseling, oral nutritional supplements (ONS) or both on energy intake and weight. Principle investigators of eligible studies provided individual participant data. We investigated the effect of nutritional intervention on meaningful increase in energy intake (>250 kcal/day) and meaningful weight gain (>1.0 kg). Logistic generalized estimating equations were performed and ORs with 95% CIs presented. RESULTS: We included data of nine studies with a total of 990 participants, aged 79.2 ± 8.2 years, 64.5% women and mean baseline BMI 23.9 ± 4.7 kg/m2. An non-significant intervention effect was observed for increase in energy intake (OR:1.59; 95% CI 0.95, 2.66) and a significant intervention effect for weight gain (OR:1.58; 95% CI 1.16, 2.17). Stratifying by type of intervention, an intervention effect on increase in energy intake was only observed for dietary counseling in combination with ONS (OR:2.28; 95% CI 1.90, 2.73). The intervention effect on increase in energy intake was greater for women, older participants, and those with lower BMI. Regarding weight gain, an intervention effect was observed for dietary counseling (OR:1.40; 95% CI 1.14, 1.73) and dietary counseling in combination with ONS (OR:2.48; 95% CI 1.92, 3.31). The intervention effect on weight gain was not influenced by participants' characteristics. CONCLUSIONS: Based on pooled data of older adults (at risk of malnutrition), nutritional interventions have a positive effect on energy intake and body weight. Dietary counseling combined with ONS is the most effective intervention.

Higher Plasma Phospholipid n-3 PUFAs, but Lower n-6 PUFAs, Are Associated with Lower Pulse Wave Velocity among Older Adults.

BACKGROUND: Higher intake of polyunsaturated fatty acids (PUFAs) and higher circulating PUFAs are associated with lower cardiovascular disease (CVD) risk. The positive influence of PUFAs might be via lowering arterial stiffness, resulting in a better CVD risk profile; however, studies investigating circulating PUFAs in relation to arterial stiffness in a general population are limited. OBJECTIVE: We investigated the associations of plasma phospholipid n-3 (ω-3) and n-6 PUFAs and fish oil intake with arterial stiffness. METHODS: We used data from a subgroup of the Age, Gene/Environment Susceptibility-Reykjavik (AGES-Reykjavik) Study (n = 501, 75.0 ± 4.96 y, 46% men), a population-based study of community-dwelling older adults. Plasma phospholipid PUFAs were measured by GC at baseline, and fish oil intake was assessed at 3 time points: early life (ages 14-19 y), midlife (ages 40-50 y), and late life (ages 66-96 y, AGES-Reykjavik baseline) with the use of a validated food-frequency questionnaire. Arterial stiffness was determined as carotid-femoral pulse wave velocity (cf-PWV) with the use of an electrocardiogram after a mean follow-up of 5.2 ± 0.3 y. Regression coefficients (95% CIs), adjusted for demographics, follow-up time, risk factors, cholesterol, triglycerides, and serum vitamin D, were calculated by linear regression per SD increment in PUFAs. RESULTS: Plasma total n-3 PUFAs, eicosapentaenoic acid, and docosahexaenoic acid were associated with lower cf-PWV [ß (95% CI): -0.036 (-0.064, -0.008); -0.031 (-0.059, -0.003); -0.036 (-0.064, -0.009), respectively]. In contrast, plasma total n-6 PUFAs and linoleic acid were associated with higher cf-PWV [0.035 (0.009, 0.061) and 0.034 (0.008, 0.059)]. Regular fish oil consumption at early-, mid-, and late-life was not associated with cf-PWV. CONCLUSIONS: Our results show a positive association between plasma n-6 PUFAs and arterial stiffness, and suggest that higher concentrations of plasma long-chain n-3 PUFAs are associated with less arterial stiffness and therein may be one of the mechanisms underlying the association between plasma n-3 PUFAs and lower CVD risk.

Plasma phospholipid fatty acids and fish-oil consumption in relation to osteoporotic fracture risk in older adults: the Age, Gene/Environment Susceptibility Study.

BACKGROUND: Polyunsaturated fatty acids (PUFAs) may play a role in fracture, but studies have been largely confined to estimates of dietary intake. OBJECTIVE: We aimed to examine associations between fatty acids measured in late life and fish-oil consumption in early life, midlife, and late life with osteoporotic fracture risk. DESIGN: Osteoporotic fractures were determined from medical records over 5-9 y of follow-up in men and women aged 66-96 y. Data were analyzed from 1438 participants including 898 participants who were randomly selected from the Age, Gene/Environment Susceptibility Study, which is an observational study, and 540 participants with incident fracture. Plasma phospholipid fatty acids were assessed by using gas chromatography. Fish-oil consumption was assessed by using validated questionnaires as never (referent), less than daily, or daily. HRs and 95% CIs adjusted for age, education, height, weight, diabetes, physical activity, and medications were estimated by using Cox regression. RESULTS: In men, the highest tertile of PUFAs, n-3 (ω-3), and eicosapentaenoic acid were associated with decreased fracture risk [HRs (95% CIs): 0.60 (95% CI: 0.41, 0.89), 0.66 (0.45, 0.95), and 0.59 (0.41, 0.86), respectively]. In women, PUFAs tended to be inversely associated with fracture risk (P-trend = 0.06), but tertiles 2 and 3 were not independently associated with risk. Tertile 2 of n-6 and arachidonic acid was associated with fracture risk in women [HRs (95% CIs): 1.43 (1.10, 1.85) and 1.42 (1.09, 1.85), respectively]. Daily fish-oil consumption in late life was associated with lower fracture risk in men (HR: 0.64; 95% CI: 0.45, 0.91). Daily fish-oil consumption in midlife was associated with lower fracture risk in women (HR: 0.75; 95% CI: 0.58, 0.98). CONCLUSIONS: Greater PUFA concentrations may be associated with lower osteoporotic fracture risk in older adults, particularly in men. Critical time periods for n-3 fatty acid consumption may differ by sex.

Plasma phospholipid PUFAs are associated with greater muscle and knee extension strength but not with changes in muscle parameters in older adults.

BACKGROUND: Muscle mass, intermuscular adipose tissue, and strength are important indicators of physical function. Dietary fatty acids (FAs) have been associated with muscle parameters such as larger size and higher strength, but large, population-based longitudinal data in older adults who are at risk of functional decline are lacking. OBJECTIVE: The objective of this study was to investigate associations between plasma phospholipid polyunsaturated fatty acids (PUFAs) and measures of muscle size, intermuscular adipose tissue, and muscle strength cross-sectionally and after 5 y of follow-up. METHODS: Data are from the Age, Gene/Environment Susceptibility-Reykjavik Study, a prospective cohort aged 66-96 y at baseline. The analytic sample included 836 participants with cross-sectional measures of muscle parameters and 459 participants with data on change in muscle parameters. PUFAs were assessed at study baseline through use of GC. Muscle parameters were assessed at baseline and after a median of 5.2 y. Muscle area and intermuscular adipose tissue were assessed with computed tomography. Maximal grip strength and knee extension strength were assessed with dynometers. Relative changes in muscle parameters (%) were calculated. Multivariate linear regression was performed to calculate unstandardized regression coefficients and P values for trends across tertiles of FAs are reported. RESULTS: Higher concentrations of total PUFAs were cross-sectionally associated with larger muscle size (P-trend: 0.002) and with greater knee extension strength (P-trend: 0.038). Higher concentrations of arachidonic acid were associated with smaller muscle size (P-trend: 0.015). Greater linoleic acid was associated with less intermuscular adipose tissue (P-trend: 0.004), whereas eicosapentaenoic acid (20:5n-3) was positively associated (P-trend: 0.047). Longitudinal analyses showed positive associations for α-linolenic acid with increased knee extension strength (P-trend: 0.014). No other associations were observed. CONCLUSIONS: These data illustrate the complex relation between plasma phospholipid PUFAs and muscle parameters; inconsistent cross-sectional relations with muscle size, intermuscular adipose tissue, and strength, and little evidence of a role in changes in muscle parameters.