Assessing tooth wear progression in non-human primates: a longitudinal study using intraoral scanning technology.

Intraoral scanners are widely used in a clinical setting for orthodontic treatments and tooth restorations, and are also useful for assessing dental wear and pathology progression. In this study, we assess the utility of using an intraoral scanner and associated software for quantifying dental tissue loss in non-human primates. An upper and lower second molar for 31 captive hamadryas baboons (Papio hamadryas) were assessed for dental tissue loss progression, giving a total sample of 62 teeth. The animals are part of the Southwest National Primate Research Center and were all fed the same monkey-chow diet over their lifetimes. Two molds of each dentition were taken at either two- or three-year intervals, and the associated casts scanned using an intraoral scanner (Medit i700). Tissue loss was calculated in WearCompare by superimposition of the two scans followed by subtraction analysis. Four individuals had dental caries, and were assessed separately. The results demonstrate the reliability of these techniques in capturing tissue loss data, evidenced by the alignment consistency between scans, lack of erroneous tissue gain between scans, and uniformity of tissue loss patterns among individuals (e.g., functional cusps showing the highest degree of wear). The average loss per mm2 per year for all samples combined was 0.05 mm3 (0.04 mm3 for females and 0.08 mm3 for males). There was no significant difference in wear progression between upper and lower molars. Substantial variation in the amount of tissue loss among individuals was found, despite their uniform diet. These findings foster multiple avenues for future research, including the exploration of wear progression across dental crowns and arcades, correlation between different types of tissue loss (e.g., attrition, erosion, fractures, caries), interplay between tissue loss and microwear/topographic analysis, and the genetic underpinnings of tissue loss variation.

Technical note: Micro-computed tomography calibration using dental tissue for bone mineral research.

Computed tomography (CT) and microcomputed tomography (µCT) require calibration against density phantoms scanned with specimens or during routine internal calibration for assessment of mineral concentration (MC) and density. In clinical studies involving bone, alternative calibration methods using bodily tissues and fluids ("phantomless" calibration) have been suggested. However, such tissues are seldom available in archeological and osteological research. This study investigates the potential of dental tissue as internal reference for calibration of µCT scans, facilitating the analysis of bone MC. We analyzed 70 molars from 24 extant primate species, including eight human teeth, each scanned with density phantoms for calibration. Our findings indicate that sampling specific regions of molars (lateral aspects of the mesial cusps) yields low variation in enamel and dentine MC values, averaging 1.27 g/cm3 (±0.03) for dentine and 2.25 g/cm3 (±0.03) for enamel. No significant differences were observed across molar types or among scanning procedures, including scanner model, resolution, and filters. An ad hoc test on 12 mandibles revealed low variance in MC between the conventional phantom and dental tissue calibration methods; all 36 measurements (low, medium, and high MC for each mandible) were within 0.05 g/cm3 of each other -81% were within 0.03 g/cm3 and 94% within 0.04 g/cm3. Based on these results, we propose a new "phantomless" calibration technique using these mean enamel and dentine MC values. The presented phantomless calibration method could aid in the assessment of bone pathology and enhance the scope of studies investigating bone structure and physical property variations in archeological, osteological, and laboratory-based research.

New horizon in improving ageing with improvisational theatre.

Cognitive decline, mental health and mindset factors can all affect the autonomy and well-being of older adults. As the number of older adults across the globe increases, interventions to improve well-being are urgently needed. Improvisational theatre (improv) and improv-based interventions are well-suited to address this need. Studies have shown that participation in improv-based interventions has a positive impact on mental health indicators, including depressive symptoms, well-being and social connectedness, as well as cognitive skills such as attention and memory. In addition, improv-based interventions have been beneficial for people with dementia, improving positive affect, self-esteem and communication. In this article, we describe improvisational theatre, or improv, and the reasons it has emerged from a form of spontaneous theatre that involves playfulness and creativity to an important tool to effect behavioural change in individuals and groups. We then review the literature on the effects of improv in ageing populations, with a focus on social, emotional and cognitive functioning. Finally, we make recommendations on designing improv-based interventions so that future research, using rigorous quantitative methods, larger sample sizes and randomised controlled trials, can expand the use of improv in addressing important factors related to autonomy and well-being in older adults.

Perceived Stress, Blood Biomarkers, and Cognitive Functioning in Older Adults.

INTRODUCTION: There is a substantial gap in knowledge regarding how perceived stress may influence the relationship between serum-measured biomarkers for Alzheimer's disease and cognitive decline. METHODS: This study consists of 1118 older adult participants from the Chicago Health and Aging Project (CHAP) (60% Black participants and 63% female participants). Linear mixed effects regression models were conducted to examine the role of perceived stress in the association between three blood biomarkers: total tau (t-tau), glial fibrillary acid protein (GFAP), and neurofilament light chain (NfL) on global cognitive decline. Stratified analysis by stress level was also conducted to evaluate the associations between each blood biomarker and baseline cognitive function and decline. All models adjusted for age, race, sex, education, time, and their interactions with time. RESULTS: The interaction of stress, NfL concentration, and time was statistically significant on global cognition ( ß = -0.064 [SE = 0.028], p = .023) and on episodic memory ( ß = -0.097 [SE = 0.036], p = .007). CONCLUSIONS: Greater stress level worsens the association between high NfL concentration and cognitive decline. Stress management interventions may be helpful to reduce the rate of cognitive decline in individuals with high concentrations of NfL.

Dietary fats and the APOE-e4 risk allele in relation to cognitive decline: a longitudinal investigation in a biracial population sample.

BACKGROUND: APOE-e4 is the strongest genetic risk factor for Alzheimer's disease. However, the influence of APOE-e4 on dietary fat intake and cognition has not been investigated. OBJECTIVE: We aim to examine the association of types of dietary fat and their association to cognitive decline among those with and without the APOE-e4 allele. METHODS: The study included 3,360 Chicago Health and Aging Project (CHAP) participants from four Southside Chicago communities. Global cognition was assessed using a composite score of episodic memory, perceptual speed, MMSE, and diet using a 144-item food frequency questionnaire. APOE genotype was assessed by the hME Sequenom mass-array platform. Longitudinal mixed-effect regression models were used to examine the association of dietary fat and the APOE-e4 allele with cognitive decline, adjusted for age, sex, education, smoking status, and calorie intake. RESULTS: The present study involved 3,360 participants with a mean age of 74 at baseline, 62% African Americans, 63% females, and a mean follow-up of 7.8 years. Among participants with the APOE-e4 risk allele, higher intakes of total and saturated fat (SFA) were associated with a faster decline in global cognition. Among individuals with the APOE-e4 risk allele, a 5% increase in calories from SFA was associated with a 21% faster decline (ß = -0.0197, P = 0.0038). In contrast, a higher intake of long-chain n-3 polyunsaturated fatty acids (LC-n3 PUFA) was associated with a slower rate of decline in global cognition among APOE-e4 carriers. Specifically, for every 1% energy increment from LC-n3 PUFA, the annual rate of global cognitive decline was slower by 0.024 standardized unit (SD 0.010, P = 0.023), about 30.4% slower annual cognitive decline. Higher SFA or other types of dietary fat were not associated with cognitive decline among APOE-e4 non-carriers. CONCLUSIONS: Our study found a significant association between SFA and faster cognitive decline, LC-n3 PUFA and slower cognitive decline among those with the APOE-e4 allele. Our findings suggested that higher intake of SFA might contribute faster cognitive decline in combination with APOE-e4 whereas LC-n3 PUFA might compensate the adverse effects of APOE-e4. The interaction between intakes of different types of dietary fat and APOE-e4 on cognitive function warrants further research.

Depressive Symptoms, Glial Fibrillary Acid Protein Concentrations, and Cognitive Decline in a Cohort Study.

BACKGROUND: Little is known about how depressive symptoms and glial fibrillary acid protein (GFAP) concentrations taken together may influence cognitive functioning. Understanding this relationship may inform strategies for screening and early intervention to decrease the rate of cognitive decline. METHODS: This study sample includes 1 169 participants from the Chicago Health and Aging Project (CHAP), consisting of 60% Black participants and 40% White participants, and 63% female participants and 37% male participants. CHAP is a population-based cohort study of older adults with a mean age of 77 years. Linear mixed-effects regression models tested the main effects of depressive symptoms and GFAP concentrations and their interactions on baseline cognitive function and cognitive decline over time. Models included adjustments for age, race, sex, education, chronic medical conditions, body mass index, smoking status, alcohol use, and their interactions with time. RESULTS: The interaction of depressive symptomology and GFAP (ß = -0.105 [standard error = 0.038], p = .006) on global cognitive function was statistically significant. Participants with depressive symptoms including and above the cutoff and high log of GFAP concentrations had more cognitive decline over time, followed by participants with depressive symptoms below the cutoff and high log of GFAP concentrations, depressive symptom scores including and above the cutoff and low log of GFAP concentrations, and depressive symptom scores below the cutoff and low log of GFAP concentrations. CONCLUSIONS: Depressive symptoms have an additive effect on the association between the log of GFAP and baseline global cognitive function.

Temporal Patterns of Change in Physical and Cognitive Performance.

BACKGROUND: This study examined the relation between declines in physical and cognitive performance in older people. METHODS: A population-based cohort of 7 483 adults (average age 72 years) were interviewed. Physical performance was assessed with 3 standardized tests and a combination of 4 cognitive tests was used to assess cognitive function. Rate of change in physical and cognitive performance was determined for each interval between interviews. In mixed effects linear regression models adjusted for age, sex, race, and study time, and change in each factor was used to predict change in the other factor. We examined time associations by using changes in the predictor measured at 1, 2, or 3 intervals before the outcome change. RESULTS: Decline in cognitive function was most strongly predicted by physical decline in the same 3-year interval. The decline in cognitive function was weaker in the 1-time interval after the decline in physical function and was not significant in later intervals. When a decline in cognitive function was used to predict a decline in physical function, the results were similar. The strongest association occurred in the same time interval so that declines in cognitive and physical performance tend to occur together. CONCLUSIONS: Decline in cognition and physical function seem to occur together in a short timeframe. It is important to investigate the reasons for these changes that are short-term to guide the development of interventions.

Association of Whole Grain Consumption and Cognitive Decline: An Investigation From a Community-Based Biracial Cohort of Older Adults.

BACKGROUND AND OBJECTIVES: To examine the association of whole grain consumption and longitudinal change in global cognition, perceptual speed, and episodic memory by different race/ethnicity. METHODS: We included 3,326 participants from the Chicago Health and Aging Project who responded to a Food Frequency Questionnaire (FFQ), with 2 or more cognitive assessments. Global cognition was assessed using a composite score of episodic memory, perceptual speed, and the Mini Mental State Examination (MMSE). Diet was assessed by a 144-item FFQ. Linear mixed-effects models were used to estimate the association of intakes of whole grains and cognitive decline. RESULTS: This study involved 3,326 participants (60.1% African American [AA], 63.7% female) with a mean age of 75 years at baseline and a mean follow-up of 6.1 years. Higher consumption of whole grains was associated with a slower rate of global cognitive decline. Among AA participants, those in the highest quintile of whole grain consumption had a slower rate of decline in global cognition (ß = 0.024, 95% CI [0.008-0.039], p = 0.004), perceptual speed (ß = 0.023, 95% CI [0.007-0.040], p = 0.005), and episodic memory (ß = 0.028, 95% CI [0.005-0.050], p = 0.01) compared with those on the lowest quintile. Regarding the amount consumed, in AA participants, those who consumed >3 servings/d vs those who consumed <1 serving/d had a slower rate of decline in global cognition (ß = 0.021, 95% CI [0.005-0.036], p = 0.0093). In White participants, with >3 servings/d, we found a suggestive association of whole grains with global cognitive decline when compared with those who consumed <1 serving/d (ß = 0.025, 95% CI [-0.003 to 0.053], p = 0.08). DISCUSSION: Among AA participants, individuals with higher consumption of whole grains and more frequent consumption of whole grain had slower decline in global cognition, perceptual speed, and episodic memory. We did not see a similar trend in White adults.

Association of Vitamin E and Cognitive Decline in Older Adults with and without the APOEɛ4 Allele: A Biracial Population-Based Community Study.

BACKGROUND: The association of different types of tocopherols (vitamin E) with cognition might vary by the APOEɛ4 allele status. OBJECTIVE: We examined the association of dietary tocopherols with cognitive decline among participants with and without the APOEɛ4 allele over a median of 12 years. METHODS: 2,193 participants from the Chicago Health and Aging Project were included in the analyses. Global cognition was assessed in three-year cycles. We used a 144-item FFQ to assess dietary intakes of tocopherols and hME Sequenom mass-array platform to assess APOE genotype. We used linear mixed effects models to examine the relationship between tocopherol from food sources and global cognitive decline. RESULTS: The mean baseline age was 74.1 (SD = 5.9) years. Among APOEɛ4 carriers, participants in the highest quintile of intakes of dietary vitamin E had a slower cognitive decline of 0.022 SDU (95% CI: 0.000, 0.043) compared to those in the lowest quintile. A higher intake of dietary α-tocopherol from food sources only was associated with slower cognitive decline in APOEɛ4 carriers (p for trend 0.002) but not among the non-carriers (p for trend 0.937). Among APOEɛ4 carriers, those in the highest quintile of intake of α-tocopherol had a 16.4% slower rate of decline of global cognition compared to those in the lowest quintile (ß= 0.034, 95% CI: 0.013, 0.054). CONCLUSIONS: Individuals consuming high α-tocopherol from food sources had slower cognitive decline among APOEɛ4 carriers. In older adults, different forms of vitamin E might moderate the relationship of APOEɛ4 with global cognition.

Neuroticism, physical activity, and cognitive functioning in a population-based cohort of older adults.

BACKGROUND: Little is known about how physical activity influences the relationship between neuroticism and cognitive function and cognitive decline. METHODS: Data from the Chicago Health and Aging Project (CHAP) was utilized to conduct this study. CHAP is a population-based cohort study of chronic conditions in older adults. Participants completed in-home interviews cycles of three years from 1993-2012. Mixed effects regression models were conducted to test the associations between physical activity, neuroticism, and the interaction between neuroticism and physical activity on outcomes: global cognitive function, global cognitive decline, episodic memory, decline in episodic memory, perceptual speed, and decline in perceptual speed. Stratified mixed effects regression models by physical activity level were conducted to test the associations between neuroticism and global cognitive function and global cognitive decline. RESULTS: A total of 7,685 participants were eligible for this study. Participants were 62% female and 64% African American. We found statistically significant associations for the interaction of high physical activity and neuroticism on baseline global cognitive function (ß = 0.017 (SE = 0.007), p = .010) and on the interaction of neuroticism and high physical activity on baseline episodic memory (ß = 0.020 (SE = .009), p = .021) and on decline in episodic memory over time (ß = -0.003 (SE = .001), p = .039). CONCLUSION: Higher physical activity lessened the association between higher neuroticism and poor cognitive outcomes.

Dietary Sugar Intake Associated with a Higher Risk of Dementia in Community-Dwelling Older Adults.

BACKGROUND: We have limited evidence for the relationship of high sugar intake with dementia risk. OBJECTIVE: To determine whether high sugar intake is associated with an increased risk of dementia in community-dwelling older adultsMethods:This study included 789 participants of the Rush Memory and Aging Project (community-based longitudinal cohort study of older adults free of known dementia at enrollment), with annual clinical assessments and complete nutrient data (obtained by validated food frequency questionnaire). Clinical diagnosis of dementia is based on the criteria of the joint working group of the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association. We used Cox proportional hazard models. RESULTS: 118 participants developed dementia during 7.3±3.8 years of follow-up. Those in the highest quintile of total sugar intake were twice as likely to develop dementia than those in the lowest quintile (Q5 versus Q1:HR=2.10 (95% CI: 1.05, 4.19) when adjusted for age, sex, education, APOEɛ4 allele, calories from sources other than sugar, physical activity, and diet score. Higher percent calories from sugar were positively associated with dementia risk (ß=0.042, p = 0.0009). In exploratory analyses, the highest versus lowest quintile of fructose and sucrose in the diet had higher dementia risk by 2.8 (95% CI: 1.38, 5.67) and 1.93 (95% CI: 1.05, 3.54) times, respectively. CONCLUSIONS: A higher intake of total sugar or total calories from sugar is associated with increased dementia risk in older adults. Among simple sugars, fructose (e.g., sweetened beverages, snacks, packaged desserts) and sucrose (table sugar in juices, desserts, candies, and commercial cereals) are associated with higher dementia risk.

Cognitive Activity Is Associated with Cognitive Function over Time in a Diverse Group of Older Adults, Independent of Baseline Biomarkers.

BACKGROUND: More frequent engagement in cognitive activity is associated with better cognitive function in older adults, but the mechanism of action is not fully understood. Debate remains whether increased cognitive activity provides a meaningful benefit for cognitive health or if decreased cognitive activity represents a prodrome of cognitive impairment. Neurological biomarkers provide a novel way to examine this relationship in the context of cognitive aging. METHODS: We examined the association of self-reported cognitive activity, cognitive function, and concentrations of three biomarkers in community-dwelling participants of a longitudinal, population-based study. Cognitive activity was measured at baseline by asking participants to rate the frequency of 7 activities: (1) viewing television, (2) listening to the radio, (3) visiting a museum, (4) playing games, such as cards, checkers, crosswords, or other puzzles or games, (5) reading books, (6) reading magazines, and (7) reading newspapers. Cognitive function was measured with a battery of four tests (Mini-Mental State Examination, Digit Symbol Test, and the immediate and delayed recall of the East Boston Test) averaged into a composite score. At baseline, we evaluated the concentration of total tau (tau), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP). RESULTS: The study sample comprised 1,168 older participants, primarily non-Hispanic Blacks (60%) and women (63%). At baseline, they were an average of 77 years old with 12.6 years of education. Mixed-effects models showed that cognitive activity was associated with better cognitive functioning at baseline and over time. These relationships remained after each biomarker was added to the model. Over an average of 6.4 years of follow-up, cognitive activity was associated with cognitive decline in the model with tau (estimate = 0.0123; p value = 0.03) and was mildly attenuated in the models with NfL (estimate = 0.0110; p value = 0.06) and GFAP (estimate = 0.0111; p value = 0.06). Biomarkers did not modify the association between cognitive activity and cognitive function over time. CONCLUSION: The benefits of cognitive activity on cognition appear to be independent of biomarkers: tau, NfL, and GFAP, measured at baseline. More frequent cognitive activity may benefit the cognitive health of older adults with a wide range of potential disease risk and presentations.

Neuroticism, Physical Activity, and Cognitive Functioning in a Population-Based Cohort of Older Adults.

Background: Little is known about how physical activity influences the relationship between neuroticism and cognitive function and cognitive decline. Methods: Data from the Chicago Health and Aging Project (CHAP) was utilized to conduct this study. CHAP is a population-based cohort study of chronic conditions in older adults. Participants completed in-home interviews cycles of three years from 1993-2012. Mixed effects regression models were conducted to test the associations between physical activity, neuroticism, and the interaction between neuroticism and global cognitive function and global cognitive decline. Stratified mixed effects regression models by physical activity level were conducted to test the associations between neuroticism and global cognitive function and global cognitive decline. Results: A total of 7,685 participants were eligible for this study. Participants were 62% female and 64% African American. We found statistically significant associations for the interaction of medium physical and neuroticism (ß = 0.014 (SE = 0.007), p = .037) and the interaction of high physical activity and neuroticism (ß = 0.021 (SE = 0.007), p = .003) on global cognitive function at baseline but not for decline over time. Stratified analysis showed that among participants with high physical activity levels, the association between neuroticism and global cognitive decline was statistically significant (ß=-0.002 (SE = 0.001), p = .023). Conclusion: Increasing physical activity level benefits the cognitive functioning of individuals with high neuroticism. Interventions should incorporate health behavior change approaches which aim to reduce characteristics of neuroticism.

Race and Apolipoprotein E-e4 Allele Status Differences in the Association Between Loneliness and Cognitive Decline.

OBJECTIVE: This study aimed to examine race and apolipoprotein E-e4 allele (APOE-e4) status differences in the longitudinal associations between loneliness and cognitive decline. METHODS: The study sample is composed of participants ( N = 7696, 64% Black participants and 36% White participants) from the Chicago Health and Aging Project, a population-based cohort study. Mixed-effects regression models were conducted to examine the longitudinal associations between loneliness on global cognitive function and individual tests of cognitive function. Models were also stratified by race and APOE-e4. RESULTS: A greater percentage of Black participants (17%) reported loneliness at baseline visit compared with White participants (12%). Black and White participants who were lonely individuals had a similar rate of decline in global cognitive function at 0.075 (95% confidence interval [CI] = -0.082 to -0.068) standard deviation unit (SDU) per year for Black participants and at 0.075 (95% CI = -0.086 to -0.063) SDU per year for White participants. Lonely participants with APOE-e4 had a higher rate of global cognitive decline at -0.102 (95% CI = -0.115 to -0.088) SDU per year than for lonely participants without APOE-e4 at -0.052 (95% CI = -0.059 to -0.045) SDU per year. CONCLUSIONS: The burden of loneliness and its relation to cognitive decline is higher among participants with APOE-e4 compared with those without APOE-e4. Loneliness is associated with cognitive decline in both Black and White participants.

Healthy lifestyle and life expectancy with and without Alzheimer's dementia: population based cohort study.

OBJECTIVE: To determine the impact of lifestyle factors on life expectancy lived with and without Alzheimer's dementia. DESIGN: Prospective cohort study. SETTING: The Chicago Health and Aging Project, a population based cohort study in the United States. PARTICIPANTS: 2449 men and women aged 65 years and older. MAIN EXPOSURE: A healthy lifestyle score was developed based on five modifiable lifestyle factors: a diet for brain health (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay-MIND diet score in upper 40% of cohort distribution), late life cognitive activities (composite score in upper 40%), moderate or vigorous physical activity (≥150 min/week), no smoking, and light to moderate alcohol consumption (women 1-15 g/day; men 1-30 g/day). MAIN OUTCOME: Life expectancy with and without Alzheimer's dementia in women and men. RESULTS: Women aged 65 with four or five healthy factors had a life expectancy of 24.2 years (95% confidence interval 22.8 to 25.5) and lived 3.1 years longer than women aged 65 with zero or one healthy factor (life expectancy 21.1 years, 19.5 to 22.4). Of the total life expectancy at age 65, women with four or five healthy factors spent 10.8% (2.6 years, 2.0 to 3.3) of their remaining years with Alzheimer's dementia, whereas women with zero or one healthy factor spent 19.3% (4.1 years, 3.2 to 5.1) with the disease. Life expectancy for women aged 65 without Alzheimer's dementia and four or five healthy factors was 21.5 years (20.0 to 22.7), and for those with zero or one healthy factor it was 17.0 years (15.5 to 18.3). Men aged 65 with four or five healthy factors had a total life expectancy of 23.1 years (21.4 to 25.6), which is 5.7 years longer than men aged 65 with zero or one healthy factor (life expectancy 17.4 years, 15.8 to 20.1). Of the total life expectancy at age 65, men with four or five healthy factors spent 6.1% (1.4 years, 0.3 to 2.0) of their remaining years with Alzheimer's dementia, and those with zero or one healthy factor spent 12.0% (2.1 years, 0.2 to 3.0) with the disease. Life expectancy for men aged 65 without Alzheimer's dementia and four or five healthy factors was 21.7 years (19.7 to 24.9), and for those with zero or one healthy factor life expectancy was 15.3 years (13.4 to 19.1). CONCLUSION: A healthy lifestyle was associated with a longer life expectancy among men and women, and they lived a larger proportion of their remaining years without Alzheimer's dementia. The life expectancy estimates might help health professionals, policy makers, and stakeholders to plan future healthcare services, costs, and needs.

Association of Subjective Memory Complaints With White Matter Hyperintensities and Cognitive Decline Among Older Adults in Chicago, Illinois.

Importance: Subjective memory complaints (SMCs) are associated with a faster cognitive decline; whether this association is also associated with structural brain alterations, such as white matter hyperintensity (WMH) volumes, requires investigation. Objective: To evaluate the association of SMCs with WMH volumes and cognitive decline and investigate the role of WMH volumes in the association between SMCs and cognitive decline. Design, Setting, and Participants: The Chicago Health and Aging Project, a population-based cohort study, enrolled adults aged 65 years or older. Data collection occurred in 3-year cycles from 1993 until 2012. Our study comprised 975 participants with magnetic resonance imaging assessments, of which 900 participants had data on SMCs and covariates, and 713 participants provided 2 or more cognitive assessments during the follow-up. Statistical analyses were conducted from May to October 2021. Exposures: SMCs were obtained from self-reported questionnaire data during clinical evaluations, and the cycle, when reported, constituted the baseline of our study. Based on the frequency and severity of concerns, we categorized participants into 3 groups, (1) no concerns, (2) moderate concerns, and (3) very worried. Main Outcomes and Measures: Volumetric magnetic resonance imaging measures of WMH volume and neuropsychological testing assessments of global cognition. Linear regression analysis was used to investigate the association between SMCs and WMH volumes in a multivariable model adjusted for age, sex, race and ethnicity, education, APOE4 status, and total intracranial volume. The association of SMCs with cognitive decline was investigated using linear mixed-effects models for age, sex, race and ethnicity, education, APOE4 status, follow-up time, and each variable in interaction with time to estimate the annual longitudinal change in cognitive function. Results: Of the 900 participants with data on SMCs, covariates, and WMH volumes, 553 (61.4%) were women, 539 (59.9%) were African American, and the mean (SD) age was 79.5 (6.2) years. SMCs were associated with a larger WMH volume and faster cognitive decline. Compared with participants with no concerns, participants who were very worried had higher WMH volumes (ß = 0.833; 95% CI, 0.203-1.463) and 174% faster cognitive decline (ß = -0.049; 95% CI, -0.076 to -0.022). The association between SMCs and cognitive decline remained statistically significant among individuals with large WMH volumes (ie, within the fourth quartile). Within the fourth quartile of WMH volumes, participants who were very worried had 428% faster cognitive decline (ß = -0.077; 95% CI, -0.144 to -0.011) compared with participants with no concerns. Conclusions and Relevance: This cohort study suggests that SMCs, frequently reported by older individuals, are an important sign of cognitive impairment, especially among people with abnormalities in brain structure, such as larger WMH volumes.

The potential of marine resources for retinal diseases: a systematic review of the molecular mechanisms.

We rely on vision more than on any other sense to obtain information about our environment. Hence, the loss or even impairment of vision profoundly affects our quality of life. Diet or food components have already demonstrated beneficial effects on the development of retinal diseases. Recently, there has been a growing interest in resources from marine animals and plants for the prevention of retinal diseases through nutrition. Especially fish intake and omega-3 fatty acids have already led to promising results, including associations with a reduced incidence of retinal diseases. However, the underlying molecular mechanisms are insufficiently explained. The aim of this review was to summarize the known mechanistic effects of marine resources on the pathophysiological processes in retinal diseases. We performed a systematic literature review following the PRISMA guidelines and identified 107 studies investigating marine resources in the context of retinal diseases. Of these, 46 studies described the underlying mechanisms including anti-inflammatory, antioxidant, antiangiogenic/vasoprotective, cytoprotective, metabolic, and retinal function effects, which we critically summarize. We further discuss perspectives on the use of marine resources for human nutrition to prevent retinal diseases with a particular focus on regulatory aspects, health claims, safety, and bioavailability.

Properties of the Cognitive Function Battery for the MIND Diet Intervention to Prevent Alzheimer's Disease.

OBJECTIVE: To evaluate the properties of the cognitive battery used in the MIND Diet Intervention to Prevent Alzheimer's Disease. The MIND Diet Intervention is a randomized control trial to determine the relative effectiveness of the MIND diet in slowing cognitive decline and reducing brain atrophy in older adults at risk for Alzheimer's dementia. METHODS: The MIND cognitive function battery was administered at baseline to 604 participants of an average age of 70 years, who agreed to participate in the diet intervention study, and was designed to measure change over time. The battery included 12 cognitive tests, measuring the 4 cognitive domains of executive function, perceptual speed, episodic memory, and semantic memory. We conducted a principal component analysis to examine the consistency between our theoretical domains and the statistical performance of participants in each domain. To further establish the validity of each domain, we regressed the domain scores against a late-life cognitive activity score, controlling for age, race, sex, and years of education. RESULTS: Four factors emerged in the principal component analyses that were similar to the theoretical domains. In regression equations, we found the expected associations with age, education, and late-life cognitive activity with each of the four cognitive domains. CONCLUSIONS: These results indicate that the MIND cognitive battery is a comprehensive and valid battery of four separate domains of cognitive function that can be used in diet intervention trials for older adults.

Genetic risk, adherence to a healthy lifestyle, and cognitive decline in African Americans and European Americans.

INTRODUCTION: We investigated the role of genetic risk and adherence to lifestyle factors on cognitive decline in African Americans and European Americans. METHODS: Using data from the Chicago Health and Aging Project (1993-2012; n = 3874), we defined the genetic risk based on presence of apolipoprotein E (APOE) ε4$\varepsilon 4$ allele and determined a healthy lifestyle using a scoring of five factors: non-smoking, exercising, being cognitively active, having a high-quality diet, and limiting alcohol use. We used linear mixed-effects models to estimate cognitive decline by genetic risk and lifestyle score. RESULTS: APOE  ε4$\varepsilon 4$ allele was associated with faster cognitive decline in both races. However, within APOE  ε4$\varepsilon 4$ carriers, adherence to a healthy lifestyle (eg., 4 to 5 healthy factors) was associated with a slower cognitive decline by 0.023 (95% confidence interval [CI] 0.004, 0.042) units/year in African Americans and 0.044 (95% CI 0.008, 0.080) units/year in European Americans. DISCUSSION: A healthy lifestyle was associated with a slower cognitive decline in African and European Americans.

Technical note: Artificial Resynthesis Technology for the experimental formation of dental microwear textures.

Dental microwear formation on the posterior dentition is largely attributed to an organism's diet. However, some have suggested that dietary and environmental abrasives contribute more to the formation process than food, calling into question the applicability of dental microwear to the reconstruction of diet in the fossil record. Creating microwear under controlled conditions would benefit this debate, but requires accurately replicating the oral environment. This study tests the applicability of Artificial Resynthesis Technology (ART 5) to create microwear textures while mitigating the challenges of past research. ART 5 is a simulator that replicates the chewing cycle, responds to changes in food texture, and simulates the actions of the oral cavity. Surgically extracted, occluding pairs of third molars (n = 2 pairs) were used in two chewing experiments: one with dried beef and another with sand added to the dried beef. High-resolution molds were taken at 0, 50, 100, 2500, and 5000 simulated chewing cycles, which equates to approximately 1 week of chewing. Preliminary results show that ART 5 produces microwear textures. Meat alone may produce enamel prism rod exposure at 5000 cycles, although attrition cannot be ruled out. Meat with sand accelerates the wear formation process, with enamel prism rods quickly obliterated and "pit-and-scratch" microwear forming at approximately 2500 cycles. Future work with ART 5 will incorporate a more thorough experimental protocol with improved controls, pH of the simulated oral environment, and grit measurements; however, these results indicate the potential of ART 5 in untangling the complex variables of dental microwear formation.