A narrative review on the potential of tomato and lycopene for the prevention of Alzheimer's disease and other dementias.

Oxidative stress is a major factor in aging and is implicated in the pathogenesis of tumors, diabetes mellitus, cardiovascular and neurodegenerative diseases, including Alzheimer Disease (AD). Bioactive constituents of tomato as polyphenols and carotenoids, among which lycopene (LYC) are effective in reducing markers of oxidative stress, and appear to have a protective modulator role on the pathogenetic mechanisms, cognitive symptoms and behavioral manifestations of these diseases in cell cultures and animal models. Epidemiological evidence indicates a consistent association between the intake of tomatoes and reduced cardiovascular and neoplastic risk. LYC deficiency is common in elders and AD patients and it is strongly predictive of mortality and poor cardiovascular (CV) outcomes. Dietary intake of tomatoes seems to be more effective than tomato/LYC supplementation. Limited evidence from human intervention trials suggests that increasing tomato intake, besides improving CV markers, enhances cognitive performances. In this narrative review, we analyze the existing evidence on the beneficial effects of tomatoes on AD-related processes or risk factors. Results support the development of promising nutritional strategies to increase the levels of tomato consumption for the prevention or treatment of AD and other dementias. Extensive well-structured research, however, is mandatory to confirm the neuroprotective effects of tomato/LYC in humans.

Acceptance and Usability of Immersive Virtual Reality in Older Adults with Objective and Subjective Cognitive Decline.

BACKGROUND: Virtual reality (VR) has recently emerged as a promising means for the administration of cognitive training of seniors at risk of dementia. Immersive VR could result in increased engagement and performances; however, its acceptance in older adults with cognitive deficits still has to be assessed. OBJECTIVE: To assess acceptance and usability of an immersive VR environment requiring real walking and active participants' interaction. METHODS: 58 seniors with mild cognitive impairment (MCI, n = 24) or subjective cognitive decline (SCD, n = 31) performed a shopping task in a virtual supermarket displayed through a head-mounted display. Subjective and objective outcomes were evaluated. RESULTS: Immersive VR was well-accepted by all but one participant (TAM3 positive subscales > 5.33), irrespective of the extent of cognitive decline. Participants enjoyed the experience (spatial presence 3.51±0.50, engagement 3.85±0.68, naturalness 3.85±0.82) and reported negligible side-effects (SSQ: 3.74; q1-q3:0-16.83). The environment was considered extremely realistic, such as to induce potentially harmful behaviors: one participant fell while trying to lean on a virtual shelf. Older participants needed more time to conclude trials. Participants with MCI committed more errors in grocery items' selection and experienced less "perceived control" over the environment. CONCLUSION: Immersive VR was acceptable and enjoyable for older adults in both groups. Cognitive deficits could induce risky behaviors, and cause issues in the interactions with virtual items. Further studies are needed to confirm acceptance of immersive VR in individuals at risk of dementia, and to extend the results to people with more severe symptoms.

Sedentary Behaviors and Physical Activity Habits Independently Affect Fat Oxidation in Fasting Conditions and Capillary Glucose Levels After Standardized Glucose-Rich Meal in Healthy Females.

PURPOSE: Sedentary behaviors and muscle inactivity are being growingly recognized as important risk factors for health, adjunctively and independently from a scarce physical activity (PA), although the metabolic mechanism underneath is barely clear. To explore the relation between sedentary behaviors (SBs) and metabolism, we measured the metabolic profile in fasting condition and after oral glucose overload in a group of women, along with objective monitoring of their PA/sedentary lifestyle habits. SUBJECTS AND METHODS: Thirteen women (age: 32.5 ± 16.1 years; BMI: 24.0 ± 3.3 kg/m2), recruited among university students and research staff, underwent indirect calorimetry to assess fat and carbohydrate contribution to energy metabolism, in fasting conditions and after a glucose-rich standard meal (about 45 g of glucose). Glucose concentration in capillary blood was determined in fasting state and 15 and 30 min after meal. Habitual PA and SBs in the previous week were continuously monitored with Actigraph accelerometers. RESULTS: After adjustment for age, the contribution of fat oxidation to metabolic energy sources, normalized for fat-free mass, in fasting conditions was significantly correlated with time spent in sitting/lying position during wake hours (p < 0.001), independent from PA habits, whereas capillary blood peak and change of glucose concentration after the meal were significantly and inversely correlated with average daily moderate to vigorous PA (p = 0.025 and p = 0.019, respectively), independent from average daily sitting/lying time. CONCLUSIONS: Here, we report for the first time a direct effect of muscle inactivity on increased fat oxidation in fasting conditions, which can be hypothesized as a preliminary condition for the development of insulin resistance. We also report the direct independent effect of PA on the capacity to respond to a glycemic load, so that SBs and reduced PA appear to concur, although independently, to the increased health risk, as elsewhere observed on an epidemiological ground.

The LIBRA Index in Relation to Cognitive Function, Functional Independence, and Psycho-Behavioral Symptoms in a Sample of Non-Institutionalized Seniors at Risk of Dementia.

BACKGROUND: Alzheimer's disease is the principal cause of dementia and is determined, in at least one third cases, by modifiable risk factors (MRF). The "Lifestyle for Brain Health (LIBRA)" index was recently developed to quantify the individual risk of progression to dementia ascribable to MRF. OBJECTIVE: The aim of this study was to investigate the association between LIBRA scores and markers of cognitive performance, functional independence, and psycho-behavioral symptoms in a community-based sample of Italian elders. METHODS: 308 senior participants with mild cognitive impairment (MCI) or subjective cognitive decline (SCD) were evaluated with a complete neuropsychological battery and semi-structured interviews for the assessment of depression, apathy, and functional autonomy. All the 12 LIBRA MRF were available for the calculation of LIBRA scores. A modified version of the index (LIBRA-2) was calculated by removing depression weight from the LIBRA index. Partial correlation analyses, controlling for age and education, assessed the association between LIBRA indices and cognitive, functional, and behavioral outcomes. Separate analyses were repeated in the MCI and SCD subgroups. RESULTS: In participants with SCD (SCDp), significant correlations existed between LIBRA and markers of impairment in global cognition, visuo-spatial attention, and semantic fluency. LIBRA-2 associated with psycho-behavioral symptoms in the whole sample and in SCDp. LIBRA-2 only associated with apathy in the MCI subgroup. CONCLUSIONS: The LIBRA index might be useful to determine the lifestyle-attributable risk of cognitive and psycho-behavioral decline in Italian seniors at risk, while in those with overt cognitive impairment, these outcomes are presumably mainly associated with non-modifiable factors.