Association between Reduction of Muscle Mass and Faster Declines in Global Cognition among Older People: A 4-Year Prospective Cohort Study.

OBJECTIVES: A few studies reported that both decrease and increase in body mass index (BMI) were associated with the development of dementia in later life. However, it is unclear what changes in body composition are associated with cognitive decline. This study investigated the longitudinal influences of changes in body composition on cognitive function among community-dwelling adults. DESIGN, SETTING AND PARTICIPANTS: This longitudinal study included older adults aged ≥60 years without cognitive impairment who participated in National Institute for Longevity Sciences - Longitudinal Study of Aging. MEASUREMENTS: Cognitive function was assessed using the MMSE. Body composition was measured by a dual-energy X-ray absorptiometry system. Then, BMI, fat mass index (FMI), fat-free mass index (FFMI), and muscle mass index (MMI) were calculated. The changes in body composition over 6 years (second wave to fifth wave) were calculated, and three groups were created: decreased group, decrease of >5%; stable group, change within 5%, and increased group, increase of >5%. In statistical analysis, a linear mixed model was applied by sex to investigate the influences of body composition changes on cognitive function over 4 years (fifth wave to seventh wave). RESULTS: This study analyzed 515 participants (mean age, 67.05 years; 53.4% men). Men with decreased group in FFMI and MMI exhibited faster declines in MMSE scores than those with stable group (ß [95% CI]: FFMI, -0.293 [-0.719 to -0.020]; MMI, -0.472 [-0.884 to -0.059]). In women, there was no significant association between body composition changes and cognitive functions. CONCLUSIONS: Decrease in fat-free mass and muscle mass is associated with faster cognitive declines in men. These results suggest the importance of continuous monitoring of muscle mass to prevent cognitive decline in later life.

Association of Dietary Intake with the Transitions of Frailty among JapaneseCommunity-Dwelling Older Adults.

BACKGROUND: Frailty is a dynamic process, with frequent transitions between frailty, prefrailty, and robust statuses over time. The effect of dietary intake on frailty transitions is unknown. OBJECTIVE: To examine the association between dietary intake and frailty transitions. DESIGN: Survey-based retrospective analysis of the National Institute for Longevity Sciences-Longitudinal Study of Aging data. SETTING: Areas neighboring the National Center for Geriatrics and Gerontology in Aichi Prefecture, Japan. PARTICIPANTS: We included 469 prefrail community dwellers aged 60-87 years who participated both in the baseline (2008-2010) and 2-year follow-up (2010-2012) surveys of the National Institute for Longevity Sciences-Longitudinal Study of Aging. MEASUREMENTS: Transitions of frailty were categorized by changes in status from baseline to follow-up: "deterioration (prefrail to frail)," "persistence (persistent prefrail)," and "reversal (prefrail to robust)." Estimated dietary (nutrients and food) intakes assessed by 3-day dietary records in each frailty transition were analyzed with a multivariate-adjusted general linear model after adjusting for sex, age, education, family income, smoking, and chronic disease. RESULTS: At the 2-year follow-up, 28%, 7%, and 65% of participants had robust, frail, and pre-frail status, respectively. Among 13 food groups, only milk and dairy product intake was positively associated with frailty reversal even after adjusting for all frailty criteria at baseline. Despite insignificant differences in the estimated mean intakes, the baseline intake of saturated fatty acids, potassium, and vitamin B1 tended to be the highest in the reversal group. The estimated mean (standard error) for milk and dairy product intake (g/day) was 79.1 (28.6), 129.3 (19.9), and 161.7 (21.7) for the deterioration, persistence, and reversal groups, respectively (P=0.0036, P-trend=0.0019). CONCLUSIONS: Daily consumption of dairy products may contribute to frailty reversal and frailty prevention among older community dwellers who consume small amounts of dairy products. Other food groups showed no association with frailty status transitions.

Low Amino Acid Score of Breakfast is Associated with the Incidence of Cognitive Impairment in Older Japanese Adults: A Community-Based Longitudinal Study.

BACKGROUND: The protein digestibility-corrected amino acid score (PDCAAS) represents the degree of utilizable dietary protein, namely the protein quality. The PDCAAS of a diet is required to be evaluated on a meal-by-meal basis, as food digestion and absorption occur with each meal intake. Although a positive association between protein intake and cognitive function has been reported, no study has investigated the association between PDCAAS of a diet and cognitive function. OBJECTIVES: To investigate the relationship between PDCAAS of a diet and cognitive impairment in older adults. DESIGN: Longitudinal epidemiological study. SETTING: Community-based setting. PARTICIPANTS: We analyzed 541 community-dwellers who participated in both baseline and follow-up survey. They were 60-83 years of age without cognitive impairment at baseline. MEASUREMENTS: Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score ≤27. Individual PDCAASs were calculated for each of three regular meals from the 3-day dietary records at baseline. Participants were classified into two groups according to the sex-specific tertiles (T1-T3) of the PDCAAS for each meal (i.e., T1 as the low score group and T2-T3 as the medium and high score group). The dependent variable was cognitive impairment observed after 4 years, and the explanatory variables were the PDCAAS groups for each meal (the medium and high group as the reference) and covariates (sex, age, body mass index, education, depressive symptoms, medical history, protein intake at each meal, and the MMSE score at baseline). Multivariable logistic regression analysis was performed to evaluate the low PDCAAS group for cognitive impairment after 4 years. RESULTS: A significant association was observed only between a low PDCAAS of breakfast and the incidence of cognitive impairment (the adjusted odds ratios [95% confidence intervals] of low PDCAAS for cognitive impairment for breakfast, lunch, and dinner were 1.58 [1.00-2.50], 0.85 [0.54-1.34], and 1.08 [0.71-1.65], respectively). CONCLUSION: A lower PDCAAS of breakfast, i.e., a diet with poor quality of protein, was associated with the incidence of cognitive impairment in older adults of the community.

Relationship between Serum Fatty Acids and Components of Physical Frailty in Community-Dwelling Japanese Older Adults.

Polyunsaturated fatty acids help maintain insulin sensitivity, mitochondrial function, and anti-inflammation. It is well known that deterioration in these areas can cause frailty. However, little is known about the differences in serum polyunsaturated fatty acid levels among frailty components. We investigated the cross-sectional relationship between frailty and serum fatty acids in 1,033 community-dwelling older adults aged 60-88 years. Polyunsaturated fatty acid concentrations were measured from fasting blood samples. The modified phenotype criteria defined frailty. Polyunsaturated fatty acid levels were compared among each component using general linear modeling after controlling for sex, age, body mass index, smoking status, household income, and medical history. Lower polyunsaturated fatty acid levels were associated with the modified frailty criteria, including shrinking and weakness (p < 0.05). Our findings suggest that serum polyunsaturated fatty acid levels differ depending on the frailty status of older adults.

The Association between Dietary Amino Acid Intake and Cognitive Decline 8 Years Later in Japanese Community-Dwelling Older Adults.

OBJECTIVES: Previous studies have reported a relationship between low protein intake and cognitive decline and have suggested that this association may be related to specific amino acid intake. However, the effects of amino acid intake on the maintenance of cognitive function have yet to be clarified. We examined the longitudinal association between dietary amino acid intake and cognitive function in community-dwelling older adults. DESIGN: Longitudinal epidemiological study. SETTING: Community-based setting. PARTICIPANTS: This study comprised 427 study participants aged 60-82 years with no cognitive decline, defined as a Mini-Mental State Examination (MMSE) score of >27 at baseline, who also participated in a follow-up. The average and standard deviation of the follow-up period was 8.2 ± 0.3 years. MEASUREMENTS: Dietary intake was assessed using three-day dietary records at baseline. Participants were classified into quartiles (Q1-Q4) based on the intake of 19 amino acids for males and females. Next, we classified participants into Q1 and Q2-Q4 groups. Cognitive function was assessed using the MMSE both at baseline and at follow-up. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between the Q1 group and cognitive decline (MMSE ≤27), using the Q2-Q4 group as a reference group. Covariates were age, sex, body mass index, years of education, severity of depressive symptoms, history of lifestyle diseases (hypertension, dyslipidemia, diabetes mellitus, stroke, and ischemic heart disease), energy intake (kcal/d), protein intake (g/d), and MMSE score at baseline. RESULTS: Cognitive decline was present in 133 (31.1%) participants. After adjustment for covariates, including total protein intake, the ORs (95% CIs) for cognitive decline were 2.40 (1.21-4.75) for lysine, 2.05 (1.02-4.09) for phenylalanine, 2.18 (1.09-4.34) for threonine, and 2.10 (1.06-4.15) for alanine. CONCLUSION: The results suggest that lysine, phenylalanine, threonine, and alanine intake is important for the maintenance of cognitive function in older people, independent of total protein intake.

Dietary factors associated with the development of physical frailty in community-dwelling older adults.

OBJECTIVES: Nutrition plays an important role in the development of frailty, and the present study examined the association between energy, macronutrient, and food intake and the development of physical frailty. DESIGN: Prospective cohort study. SETTING: The National Institute for Longevity Sciences - Longitudinal Study of Aging (NILS-LSA), a community-based study. PARTICIPANTS: Participants included 166 men and 117 women aged 65-86 years without frailty components at baseline who participated in both the sixth (2008-2010) and seventh (2010-2012) waves of the NILS-LSA. MEASUREMENTS: Physical frailty was assessed using the modified criteria established by the Cardiovascular Health Study (2001). All participants were classified as "robust (number of frailty components: 0)," "prefrail (1-2)," or "frail (3-5)." Energy, macronutrient, and food intake was calculated based on 3-day dietary records during the sixth wave. Associations between dietary intake per day and the development of frailty 2 years later (from robust at the sixth wave to prefrail/frail at the seventh wave) were examined using multiple logistic regression analysis after adjusting for sex, baseline age, and other covariables. RESULTS: Among the participants included, 36% were classified as prefrail/frail 2 years later. Higher energy [1 standard deviation (SD), odds ratio (95% confidence interval): 362 kcal, 0.68 (0.49-0.94)], protein [16 g, 0.72 (0.53-0.97)], and fat [15 g, 0.69 (0.52-0.92)] intake was negatively associated with frailty development. Higher meat [38 g, 0.68 (0.51-0.92)] and dairy [114 g, 0.73 (0.55-0.96)] intake was negatively associated with frailty development. Higher energy intake was negatively associated with the development of weakness (low grip strength) and low activity, while higher protein intake was negatively associated with the development of low activity. CONCLUSION: Increased consumption of meat and dairy products may provide sufficient protein and fat necessary for achieving higher energy intake, thereby effectively preventing physical frailty among older Japanese individuals.

Age-Related 12-Year Changes in Dietary Diversity and Food Intakes among Community-Dwelling Japanese Aged 40 to 79 Years.

OBJECTIVES: This study describes trends in dietary diversity and food intake over 12 years according to age at first participation in the study. DESIGN: Prospective cohort study. SETTING: The National Institute for Longevity Sciences - Longitudinal Study of Aging, a community-based study. PARTICIPANTS: Participants included 922 men and 879 women who participated in the first study-wave (age, 40-79 years) and also participated in at least one study-wave from the second to seventh study-wave. Study-waves were conducted biennially. MEASUREMENTS: Dietary intake was calculated from 3-day dietary records with photographs. Dietary diversity was determined using the Quantitative Index for Dietary Diversity based on food intake. A mixed-effects model was used to estimate linear changes in dietary diversity and food intake over 12 years according to age at first study-wave. RESULTS: Mean (standard deviation (SD)) follow-up time and number of study-wave visits were 9.5 (3.7) years and 5.4 (1.8), respectively. Mean (SD, range) dietary diversity score was 0.86 (0.06, 0.52-0.96) in men and 0.88 (0.04, 0.66-0.96) in women, respectively. Fixed effects for interactions of age and time with dietary diversity score were statistically significant (p<0.05). The slope of dietary diversity among men aged 40 to 55 years increased (40-year-old slope = 0.00093/year, p<0.01; 55-year-old slope = 0.00035/year, p=0.04), with a decreasing trend started at 65 years old, although this trend was not significant (65-year-old slope = -0.00003/year, p=0.88; 79-year-old slope = -0.00057/year, p=0.21). The slope of dietary diversity among women aged 40 to 44 years increased (40-year-old slope = 0.00053/year, p=0.02; 44-year-old slope = 0.00038/year, p=0.04), whereas the slope of dietary diversity among women aged 63 to 79 years decreased (63-year-old slope = -0.00033/year, p=0.03; 79-year-old slope = -0.00092/year, p<0.001). Fruit, milk and dairy intake decreased in men around their 60s; milk and dairy intake decreased in women around their 50s; and beans and fruit intake decreased in women from their 70s. CONCLUSION: Twelve-year longitudinal data showed dietary diversity declined in women in their 60s. In terms of food intake, fruit, milk and dairy intake decreased in both sexes in their 50s and 60s; such declines would lower dietary diversity.

Age-related Changes in Energy Intake and Weight in Community-dwelling Middle-aged and Elderly Japanese.

OBJECTIVE: This study attempts to describe trends in energy intake and weight change over 12 years according to age at first participation in the study. DESIGN: Prospective cohort study. SETTING: The National Institute for Longevity Sciences - Longitudinal Study of Aging (NILS-LSA), a community-based study. PARTICIPANTS: Participants included 922 men and 879 women who participated in the first study-wave (age 40-79 years) and also participated in at least one study-wave from the second to seventh study-wave. Each study-wave was conducted biennially. For individuals, the entire follow-up period was 12 years. MEASUREMENTS: Energy intake was calculated from 3-day dietary records with photographs. Weight and height were measured under a fasting state. To estimate linear changes in energy intake and weight over 12 years according to age at first study-wave, we used the mixed-effects model. RESULTS: Mean (SD) follow-up time and number of study-wave visits were 9.5 (3.7) years and 5.4 (1.8) times, respectively. The fixed effect of the interaction of age and time in energy intake and weight was statistically or marginally statistically significant both in men (p<0.01) and in women (p<0.06). In men, when energy intake was estimated according to age, the rate of decrease in energy intake increased from -6.8 to -33.8 kcal/year for ages 40-79 years. In women, the rate of decrease in energy intake slightly increased in older age groups (-9.1 to -16.7 kcal/year for ages 40-79 years). Weight increased in males in their 40s (0.07 kg/year from age 40) and started to decline by age 53. In women, weight started to decline around age 47 (-0.04 kg/year). CONCLUSION: Twelve-year longitudinal data showed energy intake declined both in men and women in their 40s, and the rate of decrease increased in older males. Weight started to decline in men in their mid-50s and women in their late 40s. Further studies that focus on energy intake and weight reduction are needed to prevent weight loss or underweight in an increasingly aging society.

Serum docosahexaenoic and eicosapentaenoic acid and risk of cognitive decline over 10 years among elderly Japanese.

BACKGROUND/OBJECTIVES: To clarify the association of serum docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels with cognitive decline over 10 years. SUBJECTS/METHODS: This study was part of the National Institute for Longevity Sciences - Longitudinal Study of Aging, and was conducted with 232 male and 198 female Japanese community-dwelling subjects aged 60-79 years in the second wave (2000-2002). Cognitive function was assessed with the Mini-Mental State Examination (MMSE) in both the second and seventh (2010-2012) waves. Fasting venous blood samples were collected in the morning, and serum DHA and EPA levels were measured. Multiple logistic regression analysis was performed among participants with an MMSE score ≥ 24 in the second wave (n=430) to estimate the odds ratio (OR) and 95% confidence interval (CI) for MMSE score ≤ 23 or MMSE score decline ≥ 4 10 years later. These estimates were based on baseline tertiles of serum DHA or EPA levels, and controlled for age, sex, education, MMSE score at baseline, alcohol consumption, current smoking, body mass index and disease history. RESULTS: Fifteen (3.5%) subjects whose MMSE score was ≤ 23 and 36 (8.3%) subjects whose MMSE score declined to ≥ 4 showed cognitive decline. Multivariate-adjusted OR (95% CI) for the lowest through highest tertiles of serum DHA to MMSE score ≤ 23 or decline ≥ 4 were 1.00 (reference), 0.11 (0.02-0.58) and 0.17 (0.04-0.74), or 1.00 (reference), 0.22 (0.08-0.61) and 0.31 (0.12-0.75), respectively (P for trend=0.01 or 0.04). Serum EPA was not associated with cognitive decline. CONCLUSIONS: The study gives some indication that a moderately high level of serum DHA might prevent cognitive decline among community-dwelling elderly Japanese individuals.

Cereal Intake Increases and Dairy Products Decrease Risk of Cognitive Decline among Elderly Female Japanese.

BACKGROUND: If cognitive decline can be prevented through changes in daily diet with no medical intervention, it will be highly significant for dementia prevention. OBJECTIVES: This longitudinal study examined the associations of different food intakes on cognitive decline among Japanese subjects. DESIGN: Prospective cohort study. SETTING: The National Institute for Longevity Sciences - Longitudinal Study of Aging, a community-based study. PARTICIPANTS: Participants included 298 males and 272 females aged 60 to 81 years at baseline who participated in the follow-up study (third to seventh wave) at least one time. MEASUREMENTS: Cognitive function was assessed with the Mini-Mental State Examination (MMSE) in all study waves. Nutritional intake was assessed using a 3-day dietary record in the second wave. Cumulative data among participants with an MMSE >27 in the second wave were analyzed using a generalized estimating equation. Multivariate adjusted odds ratios (OR) and 95% confidence intervals (CI) for an MMSE score ≤27 in each study wave according to a 1 standard deviation (SD) increase of each food intake at baseline were estimated, after adjusting for age, follow-up time, MMSE score at baseline, education, body mass index, annual household income, current smoking status, energy intake, and history of diseases. RESULTS: In men, after adjusting for age, and follow-up period, MMSE score at baseline, the adjusted OR for a decline in MMSE score was 1.20 (95% CI, 1.02-1.42; p=0.032) with a 1-SD increase in cereal intake. After adjusting for education and other confounding variables, the OR for a decrease in MMSE score did not reach statistical significance for this variable. In women, multivariate adjusted OR for MMSE decline was 1.43 (95% CI, 1.15-1.77; p=0.001) with a 1-SD increase in cereal intake and 0.80 (95% CI, 0.65-0.98; p=0.034) with a 1-SD increase in milk and dairy product intake. CONCLUSIONS: This study indicates that a 1-SD (108 g/day) decrease in cereal intake and a 1-SD (128 g/day) increase in milk and dairy product intake may have an influence of cognitive decline in community-dwelling Japanese women aged 60 years and older. Further studies are needed in order to explore the potential causal relationship.

[Construction of a scale of attitude toward death in adolescence and its validity and reliability].

The purpose of this paper was to construct a scale that measures the multidimensional attitude toward death in adolescence. Based on preliminary open-ended format survey, a scale of attitude toward death consisting of 67 items was constructed. This scale was administered to 1,071 adolescents. Factor analysis with varimax rotation indicated 6 subscales: "fear of death", "intention to live out own life", "meaning of death for life", "underrating of death", "belief in existence of afterlife", "choice of death-of-body/death-of-mind". For these subscales, the coefficients of alpha ranged from .60 to .84, and the coefficients of test-retest reliability with a three-week interval ranged from .68 to .93. The validity of the subscales was investigated through the relations with Templer's Death Anxiety Scale and several developmental indices.