Self-reported dietary intake of potassium, calcium, and magnesium and risk of dementia in the Japanese: the Hisayama Study

Magnesium for disease treatment and prevention: emerging mechanisms and opportunities

Magnesium (Mg2+) is a commonly used dietary supplement for the prevention and treatment of diseases. However, the efficacy and mechanisms of action of Mg2+ in most diseases have been controversial because of conflicting findings in earlier studies. Recent clinical and preclinical studies provide novel insights into the use of Mg2+ for the treatment and prevention of diseases affecting different organ systems. In this review, we provide an overview of recent clinical evidence for, and controversies over, the medical benefits of Mg2+. In addition, we critically discuss recent advances in understanding the mechanisms of action of Mg2+, which could enable the development of novel targeted therapies.

Magnesium and Cognitive Health in Adults: A Systematic Review and Meta-Analysis

Magnesium (Mg) plays a key role in neurological functioning and manifestations. However, the evidence from randomized controlled trials (RCTs) and cohorts on Mg and cognitive health among adults has not been systematically reviewed. We aimed to examine the associations of various Mg forms (supplements, dietary intake, and biomarkers) with cognitive outcomes by summarizing evidence from RCTs and cohorts. PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched for relevant peer-reviewed articles published up to May 3, 2024. Three random-effects models were performed, when appropriate, to evaluate the relationship between Mg and cognitive outcomes: 1) linear meta-regression, 2) non-linear (quadratic) meta-regression, and 3) meta-analysis using Mg variables categorized based on pre-existing recommendations. Three RCTs and 12 cohort studies were included in this systematic review. Evidence from the limited numbers of RCTs was insufficient to draw conclusions on the effects of Mg supplements. Cohort studies showed inconsistent dose-response relationships between dietary Mg and cognitive disorders, with high heterogeneity across populations. However, consistent U-shape associations of serum Mg with all-cause dementia and cognitive impairment were found in cohorts, suggesting an optimal serum Mg concentration around 0.85 mmol/L. This non-linear association was detected in meta-regression (Pquadratic = 0.003) and in meta-analysis based on the reference interval of serum Mg (0.75-0.95 mmol/L) [<0.75 compared with 0.85 mmol/L: pooled hazard ratio (HR) = 1.43; 95% confidence interval (CI) = 1.05, 1.93; >0.95 compared with 0.85 mmol/L: pooled HR = 1.30; 95% CI = 1.03, 1.64]. More evidence from RCTs and cohorts is warranted. Future cohort studies should evaluate various Mg biomarkers and collect repeated measurements of Mg intake over time, considering different sources (diet or supplements) and factors affecting absorption (e.g., calcium-to-Mg intake ratio). This systematic review was pre-registered in PROSPERO (CRD42023423663).

Adherence to the Mediterranean Diet, Sodium and Potassium Intake in People at a High Risk of Dementia

Adequate sodium and potassium intake, along with adherence to the Mediterranean diet (MedDiet), are key factors for preventing hypertension and cerebrovascular diseases. However, data on the consumption of these nutrients within the MedDiet are scarce. This cross-sectional study aims to assess the association between MedDiet adherence and sodium/potassium intake in the MIND-Matosinhos randomized controlled trial, targeting Portuguese adults at a high risk of dementia. Good adherence to the MedDiet was defined using the Portuguese Mediterranean Diet Adherence Screener questionnaire (≥10 points), and both sodium/potassium intakes were estimated from 24-hour urine collections. The association between MedDiet adherence and these nutrients' intake (dichotomized by the median) was quantified by calculating odds ratios (OR) and respective 95% confidence intervals (95% CI) using a logistic regression. A total of 169 individuals (60.9% female; median age: 70 years; range: 36-85 years) were included. Good adherence to the MedDiet was observed among 18.3% of the sample. After adjusting for sex, age, education and using antihypertensive drugs, good MedDiet adherence was associated with higher sodium (OR = 3.11; 95% CI: 1.27-7.65) and potassium intake (OR = 9.74; 95% CI: 3.14-30.26). Increased adherence to the MedDiet may contribute to a higher potassium intake but seems to have limited effects on the adequacy of sodium levels.

Association between dietary magnesium intake, inflammation, and neurodegeneration

BACKGROUND

Consistent evidence shows that magnesium (Mg) intake is associated with lower blood pressure (BP), and that lower BP is associated with improved cerebral health. However, recent findings indicate that the positive effect of dietary Mg intake on cerebral health is not mediated by a decrease in BP. As Mg's anti-inflammatory action is a plausible alternative mechanism, the objective of this study was to investigate the associations between Mg intake and inflammation to determine whether it mediates any neuroprotective effect.

METHODS

Participants from the UK Biobank (n = 5775, aged 40-73 years, 54.7% female) were assessed for dietary magnesium using an online food questionnaire, brain and white matter lesion (WML) volumes were segmented with FreeSurfer software, and inflammation markers including high-sensitivity C-reactive protein (hs-CRP), leukocyte, erythrocyte count, and Glycoprotein acetylation (GlycA) were measured using specific laboratory techniques such as immunoturbidimetry, automated cell counting, and nuclear magnetic resonance. Hierarchical linear regression models were performed to investigate the association between dietary Mg, and inflammatory markers and between dietary Mg, brain and WMLs volumes. Mediation analysis was performed to test a possible mediation role of inflammation on the association between dietary Mg and brain and WMLs volumes.

RESULTS

Higher dietary Mg intake was associated with lower inflammation: hs-CRP level (- 0.0497%; 95% confidence interval [CI] - 0.0497%,  - 0.0199%) leukocytes count (- 0.0015%; 95%CI - 0.00151%,  - 0.0011%), and GlycA (- 0.0519%; 95%CI - 0.1298%,  - 0.0129%). Moreover, higher dietary Mg intake was associated with larger grey matter volume (0.010%; 95%CI 0.004%, 0.017%), white matter volume (0.012%; 95%CI 0.003,  0.022) and right hippocampal volume (0.002%; 95%CI 0.0007, -0.0025%). Lower hs-CRP levels mediated the positive association between higher dietary Mg intake and larger grey matter volume.

CONCLUSIONS

The anti-inflammatory effects of dietary Mg intake in the general population, appears to mediate its neuroprotective effect.

Supplements for cognitive ability in patients with mild cognitive impairment or Alzheimer's disease: a protocol for systematic review and network meta-analysis of randomised controlled trials

INTRODUCTION

Considering the increasing incidence of Alzheimer's disease (AD) and mild cognitive impairment (MCI) worldwide, there is an urgent need to identify efficacious, safe and convenient treatments. Numerous investigations have been conducted on the use of supplements in this domain, with oral supplementation emerging as a viable therapeutic approach for AD or MCI. Nevertheless, given the multitude of available supplements, it becomes imperative to identify the optimal treatment regimen.

METHODS AND ANALYSIS

Eight academic databases and three clinical trial registries will be searched from their inception to 1 June 2023. To identify randomised controlled trials investigating the effects of supplements on patients with AD or MCI, two independent reviewers (X-YZ and Y-QL) will extract relevant information from eligible articles, while the risk of bias in the included studies will be assessed using the Rob 2.0 tool developed by the Cochrane Collaboration. The primary outcome of interest is the overall cognitive function. Pair-wise meta-analysis will be conducted using RevMan V.5.3, while network meta-analysis will be carried out using Stata 17.0 and ADDIS 1.16.8. Heterogeneity test, data synthesis and subgroup analysis will be performed if necessary. The GRADE system will be employed to assess the quality of evidence. This study is scheduled to commence on 1 June 2023 and conclude on 1 October 2023.

ETHICS AND DISSEMINATION

Ethics approval is not required for systematic review and network meta-analysis. The results will be submitted to a peer-reviewed journal or at a conference.

TRIAL REGISTRATION NUMBER

PROSPERO (CRD42023414700).

A review of dairy food intake for improving health among black geriatrics in the US

The transition to older adulthood is generally marked by progressive declines in body composition, metabolism, cognitive function, and immunity. For socially disadvantaged geriatric populations such as Black Americans, this life stage may also include additional stressors, including dealing with discrimination, poor access to healthcare, and food insecurity. These types of chronic stressors are linked to a higher allostatic load, which is associated with accelerated biological aging, higher rates of adverse health outcomes, and an overall lower quality of life. Of the numerous factors involved in healthy aging, a growing body of research indicates that consuming a higher quality diet that is rich in fruits, vegetables, whole grains, protein foods, and dairy foods, is one of the most potent factors for helping to protect against age-related disease progression. Among the food groups listed above that are recommended by the 2020-2025 Dietary Guidelines for Americans dairy foods are unique in their ability to provide several of the essential nutrients (e.g., high-quality protein, calcium, potassium, vitamin B12, and vitamin D in fortified products) that are most often inadequately consumed by older Black Americans. However, dairy is the most inadequately consumed food group in the US, with older Black adults consuming fewer than half of the 3 daily recommended servings. Therefore, this review examines the current body of evidence exploring the links between dairy intake and age-related disease risk, with a special focus on health and disparities among older Black Americans. Overall, the evidence from most systematic reviews and/or meta-analyses focused on dairy intake and musculoskeletal health suggest that higher dairy intake across the life span, and especially from fermented and fortified products, is associated with better bone and muscle health outcomes in older adults. The evidence on dairy intake and neurocognitive and immune outcomes among older adults holds significant promise for potential benefits, but most of these results are sourced from individual studies or narrative reviews and are not currently corroborated in systematic reviews or meta-analyses. Additionally, most of the research on dairy intake and age-related disease risk has been performed in White populations and can only be extrapolated to Black populations. Nonetheless, older Black populations who do not meet the DGA recommended 3 servings of dairy per day due to lactose intolerance, restrictive dietary patterns, or for other reasons, are likely falling short of several of the nutritional requirements necessary to support healthy aging.

Development and Validation of the Meiji Nutritional Profiling System (Meiji NPS) to Address Dietary Needs of Adults and Older Adults in Japan

This study introduces the Meiji Nutritional Profiling System (Meiji NPS), which was specifically designed to respond to age-related shifts in nutrient requirements among Japanese adults (<65 years old) and older adults (≥65 years old). Japan has one of the most aged societies in the world. The health issues of interest are malnutrition and lifestyle-related diseases among adults and frailty among older adults. Two versions of the NPS were developed based on nutrients to encourage (protein, dietary fibers, calcium, iron, and vitamin D), food groups to encourage (fruits, vegetables, nuts, legumes, and dairy), and nutrients to limit (energy, saturated fatty acids, sugars, and salt equivalents). The Meiji NPS for older adults did not include iron or saturated fatty acids. The algorithms were based on the Nutrient-Rich Foods Index (NRF). The convergent validity between the Meiji NPS and the existing NPSs for the same foods was confirmed using Spearman's correlation coefficients (NRF: r = 0.67 for adults and r = 0.60 for older adults; Health Star Rating: r = 0.64 for adults and r = 0.61 for older adults). The Meiji NPS may be useful for nutritional evaluation and reformulation of food products, tailored to adults and older adults to ameliorate health issues in Japan.

Comparison of Eating Habits, Body Composition and Densitometric Parameters between Subjects with Normal Cognitive Function and Mild Cognitive Impairment: An Observational Study

The role of nutrition in the ageing process of the brain is pivotal. Therefore, the study aimed to compare eating habits, body composition and densitometric parameters between subjects with normal cognitive function (NCF) and mild cognitive impairment (MCI). A total of 95 subjects with NCF (74% of women) and 95 individuals with MCI (77% of women) aged 50-70 years were studied. Densitometric parameters were evaluated using dual-energy X-ray absorptiometry methods. Eating habits were assessed using the food frequency questionnaire and 3-day diary records, and advanced glycation end products (AGEs) intake was calculated. Significant differences between groups were detected for the %fat in the right arm (NCF vs. MCI: 38.4 (30.4-46.8) vs. 43.5 (35.5-49.2)%, p = 0.0407). Moreover, the MCI group had a significantly lower intake of calcium (p = 0.0010), phosphor (p = 0.0411), vitamins B2 (p = 0.0138) and B12 (p = 0.0024) compared to the NCF group, with both groups also differing in the frequency of butter (p = 0.0191) and fermented milk beverages (p = 0.0398) intake. Analysis restricted to women showed significant differences between groups in right arm %fat, VAT mass, calcium, vitamins B2, B12, butter and fermented milk products intake, while in men, differences were detected in the intake of calcium, iodine, vitamin B1, water and AGEs. In conclusion, subjects with NCF and MCI have comparable densitometric variables but differ significantly in some body composition parameters and the intake of some food groups and nutrients.

Adequate dietary magnesium intake may protect females but not males older than 55 years from cognitive impairment

BACKGROUND

Magnesium is an essential nutrient required to maintain brain health throughout life, and adequate magnesium intake is positively associated with cognitive performance in older adults. However, sex differences in magnesium metabolism have not been adequately assessed in humans.

OBJECTIVES

We investigated sex differences in the effect of dietary magnesium intake and the risk of different types of cognitive impairment in older Chinese adults.

METHODS

We collected and assessed dietary data and cognitive function status in people aged 55 years and older in northern China who participated in the Community Cohort Study of Nervous System Diseases from 2018 to 2019 to explore the relationship between dietary magnesium intake and the risk of each type of mild cognitive impairment (MCI) in sex-specific cohorts of older adults.

RESULTS

The study included 612 people: 260 (42.5%) men and 352 (57.5%) women. Logistic regression results showed that for the total sample and women's sample, high dietary magnesium intake reduced the risk of amnestic MCI (ORtotal = 0.300; ORwomen = 0.190) and multidomain amnestic MCI (ORtotal = 0.225; ORwomen = 0.145). The results of restricted cubic spline analysis showed that the risk of amnestic MCI (ptotal = 0.0193; pwomen = 0.0351) and multidomain amnestic MCI (ptotal = 0.0089; pwomen = 0.0096) in the total sample and women's sample gradually decreased with increasing dietary magnesium intake.

CONCLUSIONS

The results suggest that adequate magnesium intake may have a preventive effect against the risk of MCI in older women.

Association between dietary diversity and cognitive impairment in community-dwelling older adults

AIM

The present study aimed to examine whether dietary diversity is associated with cognitive impairment, including mild cognitive impairment (MCI), in community-dwelling older Japanese adults.

METHODS

This cross-sectional study was carried out in a general community setting. MCI and global cognitive impairment (GCI) were assessed using the Mini-Mental State Examination and National Center for Geriatrics and Gerontology-Functional Assessment Tool, which are multicomponent neurocognitive tests that include memory attention, executive function and processing speed. Dietary diversity was assessed using the diet variety score. The diet variety score assessed the 1-week consumption frequency of 10 food groups, and either 0 or 1 point was allocated to each category based on the following responses: (i) "eat almost every day" (1 point); and (ii) "not eaten almost daily" (0 points). Older adults with a diet variety score of ≥3 points were defined as having high dietary diversity.

RESULTS

Data included 8987 older adults (mean age 73.9 ± 5.5 years; men 44.3%). The overall prevalences of MCI and GCI were 17.1% (n = 1538) and 8.4% (n = 753), respectively. The proportion of patients with a high dietary diversity was 69.9% (n = 6286). Multinomial logistic regression analysis revealed high dietary diversity was associated with MCI (OR 0.83, 95% CI 0.73-0.94) and GCI (OR 0.77, 95% CI 0.65-0.92) after adjusting for covariates.

CONCLUSIONS

This study had a large sample size of older Japanese adults, and showed that high dietary diversity was associated with a lower proportion of MCI and GCI among older adults. Geriatr Gerontol Int 2024; 24: 75-81.

Hypertension & dementia: Pathophysiology & potential utility of antihypertensives in reducing disease burden

Dementia is a common cause of disability and dependency among the elderly due to its progressive neurodegenerative nature. As there is currently no curative therapy, it is of major importance to identify new ways to reduce its prevalence. Hypertension is recognised as a modifiable risk factor for dementia, particularly for the two most common subtypes; vascular dementia (VaD) and Alzheimer's disease (AD). From the current literature, identified through a comprehensive literature search of PubMed and Cochrane Library, this review aims to establish the stage in adulthood when hypertension becomes a risk for cognitive decline and dementia, and whether antihypertensive treatment is effective as a preventative therapy. Observational studies generally found hypertension in mid-life (age 45-64) to be correlated with an increased risk of cognitive decline and dementia incidence, including both VaD and AD. Hypertension manifesting in late life (age ≥ 65) was demonstrated to be less of a risk, to the extent that incidences of high blood pressure (BP) in the very elderly (age ≥ 75) may even be related to reduced incidence of dementias. Despite the evidence linking hypertension to dementia, there were conflicting findings as to whether the use of antihypertensives was beneficial for its prevention and this conflicting evidence and inconsistent results could be due to the methodological differences between the reviewed observational and randomised controlled trials. Furthermore, dihydropyridine calcium channel blockers and potassium-sparing diuretics were proposed to have neuroprotective properties in addition to BP lowering. Overall, if antihypertensives are confirmed to be beneficial by larger-scale homogenous trials with longer follow-up durations, treatment of hypertension, particularly in mid-life, could be an effective strategy to considerably lower the prevalence of dementia. Furthermore, greater clarification of the neuroprotective properties that some antihypertensives possess will allow for better clinical practice guidance on the choice of antihypertensive class for both BP lowering and dementia prevention.

Association of Dietary and Supplement Intake of Antioxidants with Risk of Dementia: A Meta-Analysis of Cohort Studies

Background

Dementia is a neuropsychiatric disorder with cognitive decline due to multiple factors. With the arrival of the aging population, the incidence of dementia has gradually increased. There is still no effective treatment for dementia, and therefore, the prevention of dementia has become crucial. Oxidative stress is considered to be one of the pathogenesis of dementia; therefore, antioxidant therapy and prevention of dementia have been gradually proposed.

Objective

Our meta-analysis aimed to investigate the association of antioxidants with risk of dementia.

Methods

We searched PubMed, Embase, and Web of Science databases for articles on antioxidants associated with dementia risk, and those containing cohort studies with high-dose versus low-dose controls were included in our meta-analysis. The resulting risk ratios (RR) and hazard ratios (HR) and 95% confidence intervals were statistically analyzed using Stata12.0 free software.

Results

A total of 17 articles were included in this meta-analysis. Of 98,264 participants, 7,425 had dementia after 3-23 years of follow-up. The results of the meta-analysis showed a trend towards a lower incidence of dementia with high intake of antioxidants (RR = 0.84, 95% CI 0.77-1.19 I2 = 54.6%), but this was not statistically significant. High antioxidant intake significantly reduced the incidence of Alzheimer 's disease (RR = 0.85, 95% CI 0.79-0.92 I2 = 45.5%), and we additionally carried out subgroup analyses by nutrient type, diet or supplement, region, and study quality score.

Conclusion

Dietary intake of antioxidants or supplements reduces both the risk of dementia and the risk of Alzheimer's disease.

Micronutrient Deficiencies in Older Adults in Latin-America: A Narrative Review

BACKGROUND

The population in Latin America and Caribbean (LAC) has experienced a major demographic transition with increased numbers of older adults (OA). This change brings opportunities in the public health sector to implement health prevention interventions and delay the onset of geriatric syndromes. Micronutrients play an important role in the maintenance of biological function which contributes to longevity. Micronutrient deficiencies (MD) in OA increase the risk for onset of chronic comorbidities and geriatric syndromes.

AIM

To review and summarize the existing data on micronutrient status in OA in the LAC region and discuss the gaps and challenges in public health approaches to address deficiencies.

METHODS

Literature review in Medline for records describing nutritional biomarkers in older adults (≥ 60y) from community dwelling and population-based studies in LAC.

RESULTS

Few countries (including Chile, Ecuador, Costa Rica, Brazil, and Mexico) have documented one or more nutritional deficiencies for OA in national health surveys, however across the entire region, evidence of micronutrient levels is scarce. Some surveys have documented a high prevalence and large heterogeneity in the prevalence of vitamin D followed by B12 deficiency, being the 2 MDs most studied due their effects on cognition, frailty, and bone mineral density in the OA population. Other MD including C, E, A, copper, zinc, iron, and selenium have also been reported.

CONCLUSION

Information on the micronutrient status in OA from LAC is poorly documented. Research and capacity building initiatives in the region are crucial to develop tailored strategies that address the specific nutritional needs and challenges faced by the ageing population in Latin-America.

Improving Cognitive Function with Nutritional Supplements in Aging: A Comprehensive Narrative Review of Clinical Studies Investigating the Effects of Vitamins, Minerals, Antioxidants, and Other Dietary Supplements

Cognitive impairment and dementia are burgeoning public health concerns, especially given the increasing longevity of the global population. These conditions not only affect the quality of life of individuals and their families, but also pose significant economic burdens on healthcare systems. In this context, our comprehensive narrative review critically examines the role of nutritional supplements in mitigating cognitive decline. Amidst growing interest in non-pharmacological interventions for cognitive enhancement, this review delves into the efficacy of vitamins, minerals, antioxidants, and other dietary supplements. Through a systematic evaluation of randomized controlled trials, observational studies, and meta-analysis, this review focuses on outcomes such as memory enhancement, attention improvement, executive function support, and neuroprotection. The findings suggest a complex interplay between nutritional supplementation and cognitive health, with some supplements showing promising results and others displaying limited or context-dependent effectiveness. The review highlights the importance of dosage, bioavailability, and individual differences in response to supplementation. Additionally, it addresses safety concerns and potential interactions with conventional treatments. By providing a clear overview of current scientific knowledge, this review aims to guide healthcare professionals and researchers in making informed decisions about the use of nutritional supplements for cognitive health.

Tooth Loss as a Predictor of Long-Term Care Requirements in the Elderly: A Study in Kobe City, Japan

INTRODUCTION

The Kobe project, which utilizes prospective data from the national health insurance system, focuses on early detection and preventive strategies through the Frail Kenshin health check-up program. Previous research has underscored the correlation between tooth loss and the decline in physical and cognitive functions. In this study, using Kobe project data, we examined the link between remaining teeth and long-term care needs in individuals aged 64-65 years, with primary and secondary objectives involving various health parameters and quality of life.

METHODS

We analyzed baseline data from a prospective study conducted alongside the Frail Check program for generally healthy individuals aged 64-65 years to examine the relationship between the number of remaining teeth and various health indicators. This study focused on citizens aged 64-65 years to identify those at risk of needing long-term care by the age of 65 years.

RESULTS

Data from 1,530 participants were obtained, excluding eight individuals for specific reasons. At the end of the follow-up period, 41 (2.7%) individuals required support and 15 (1.0%) needed long-term care alone. The data revealed a significant association between the number of remaining teeth and the need for long-term care or support, as demonstrated by the Cochran-Armitage trend test (p<0.001). Although trends were noted for nutrition and total Cognitive Functional Instrument Self scores, they did not reach statistical significance. Additionally, a decrease in the number of remaining teeth was significantly associated with worse European Quality of Life Five Dimensions (EQ-5D-5L) visual analog scale scores, mobility, and regular activities (p<0.001).

CONCLUSION

Tooth loss indicates the potential long-term care needs of older adults. Monitoring oral health is crucial for addressing care requirements.

Association between Mineral Intake and Cognition Evaluated by Montreal Cognitive Assessment (MoCA): A Cross-Sectional Study

BACKGROUND

Mineral intake may protect against cognitive impairment (CI) and all-cause dementia, which affects a large number of adults worldwide. The aim of this study was to investigate the association between mineral intake and Montreal Cognitive Assessment (MoCA), which is a sensitive and specific test.

METHODS

In total, 201 adults were included in a cross-sectional study. They completed a three-day dietary record to estimate their average daily intake of minerals. Contributions to dietary reference intakes (DRIs) were also calculated. The participants were divided into tertiles according to their mineral intake. CI classifications were determined via the MoCA (score < 26). Apolipoprotein E (APOE) genotyping was carried out, and the patients' anthropometric measurements and physical activity, health and personal data were collected.

RESULTS

The prevalence of CI in this selective sample was 54.2% (34.3% females and 19.9% males). In women, being in the third tertiles of iron and manganese intake was associated with lower odds of having CI (OR [95% CI]: 0.32 [0.11 ± 0.93]; 0.33 [0.12 ± 0.93], p < 0.05). No significant differences were observed for any of the nutrients studied in men.

CONCLUSIONS

These findings suggest that a low mineral intake, especially low iron and manganese intake in women, is associated with a worse cognition as assessed by MoCA.

Oral calcium and vitamin D supplements differentially alter exploratory, anxiety-like behaviors and memory in male rats

Oral calcium and calcium plus vitamin D supplements are commonly prescribed to several groups of patients, e.g., osteoporosis, fracture, and calcium deficiency. Adequate and steady extracellular calcium levels are essential for neuronal activity, whereas certain forms of calcium supplement (e.g., CaCO3) probably interfere with memory function. However, it was unclear whether a long-term use of ionized calcium (calcium chloride in drinking water ad libitum), vitamin D supplement (oral gavage) or the combination of both affected anxiety and memory, the latter of which was probably dependent on the hippocampal neurogenesis. Here, we aimed to determine the effects of calcium and/or vitamin D supplement on the anxiety- and memory-related behaviors and the expression of doublecortin (DCX), an indirect proxy indicator of hippocampal neurogenesis. Eight-week-old male Wistar rats were divided into 4 groups, i.e., control, calcium chloride-, 400 UI/kg vitamin D3-, and calcium chloride plus vitamin D-treated groups. After 4 weeks of treatment, anxiety-, exploration- and recognition memory-related behaviors were evaluated by elevated pulse-maze (EPM), open field test (OFT), and novel object recognition (NOR), respectively. The hippocampi were investigated for the expression of DCX protein by Western blot analysis. We found that oral calcium supplement increased exploratory behavior as evaluated by OFT and the recognition index in NOR test without any effect on anxiety behavior in EPM. On the other hand, vitamin D supplement was found to reduce anxiety-like behaviors. Significant upregulation of DCX protein expression was observed in the hippocampus of both calcium- and vitamin D-treated rats, suggesting their positive effects on neurogenesis. In conclusion, oral calcium and vitamin D supplements positively affected exploratory, anxiety-like behaviors and/or memory in male rats. Thus, they potentially benefit on mood and memory in osteoporotic patients beyond bone metabolism.

Nutrition and Healthy Ageing in Asia: A Systematic Review

BACKGROUND

Nutrition plays a key role in modulating the likelihood of healthy ageing. In the present study, we aimed to conduct a systematic review to assess the impact of nutrition on healthy ageing in Asia.

METHODS

The systematic review was registered in the International Prospective Register of Systematic Reviews database (CRD42023408936) and conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Web of Science, and Embase databases were searched up to February 2023 without language restrictions. We included prospective cohort studies that evaluated the associations of intake of a single food or consumption of a single nutrient at midlife; adherence to various dietary patterns at midlife; and improved adherence to dietary patterns from mid- to late life with the likelihood of healthy ageing and its components.

RESULTS

Out of 16,373 records, we included 71 papers comprising 24 cohorts from Singapore, China, Japan, and Thailand. The healthy ageing components included cognitive function, physical function, and depression. The majority of studies supported the observation that the likelihood of healthy ageing and its components in late life was positively increased by a higher consumption of healthy foods, such as vegetables, fruits, fish, nuts, legumes, tea, milk, and dairy, at midlife, and also by greater adherence to dietary patterns with high diversity scores or high total antioxidant capacities. Furthermore, improved adherence to healthy dietary patterns from mid- to late life also increased the likelihood of healthy ageing in late life.

CONCLUSION

Consuming healthy foods and adhering to healthy dietary patterns at midlife can promote the likelihood of healthy ageing. Moreover, improving diet quality from mid- to late life can still be beneficial.

Dietary sodium/potassium intake and cognitive impairment in older patients with hypertension: Data from NHANES 2011-2014

This study aimed to assess the relationship between dietary sodium/potassium intake and cognition in elderly individuals with hypertension. We designed a cross-sectional study based on the 2011-2014 National Health and Nutrition Examination Survey (NHANES) 2011-2014. A multivariable-logistic regression analysis was performed to analyze the relationship between sodium/potassium intake and cognitive impairment. Restricted cubic spline (RCS) based on regression analysis to assess the nonlinear dose-response relationship between dietary sodium intake and cognitive performance. Out of the 2276 participants included in this study, 1670 patients had hypertension. Compared with the lowest quartile of dietary sodium intake, the lowest weighted odds ratio of cognitive impairment in DSST was observed in Q4 (OR = 0.45, 0.29-0.70), and a similar trend was observed in AFT (OR = 0.34, 0.18-0.65). After adjusting the covariates, the lowest weighted multivariable-adjusted OR of cognitive impairment in DSST were also observed in Q4 (OR = 0.47, 0.26-0.84) compared with the lowest quartile of dietary sodium intake. The RCS results showed that dietary sodium intake was U-shaped and associated with the risk of cognitive impairment in the DSST (P_{non-linearity}  = 0.0067). In addition, no significant association was observed between dietary potassium intake and different dimensions of cognitive performance. In conclusion, excessively high and low low dietary sodium were associated with impairment of specific processing speed, sustained attention, and working memory for elderly patients with hypertension in the United States. However, no association was observed between dietary potassium intake and cognition.

Dietary magnesium intake is related to larger brain volumes and lower white matter lesions with notable sex differences

PURPOSE

To examine the association between dietary magnesium (Mg) intake and brain volumes and white matter lesions (WMLs) in middle to early old age.

METHODS

Participants (aged 40-73 years) from UK Biobank (n = 6001) were included and stratified by sex. Dietary Mg was measured using an online computerised 24 h recall questionnaire to estimate daily Mg intake. Latent class analysis and hierarchical linear regression models were performed to investigate the association between baseline dietary Mg, Mg trajectories, and brain volumes and WMLs. Associations between baseline Mg, and baseline blood pressure (BP) measures, and baseline Mg, Mg trajectories and BP changes (between baseline and wave 2) were also investigated to assess whether BP mediates the link between Mg intake and brain health. All analyses controlled for health and socio-demographic covariates. Possible interactions between menopausal status and Mg trajectories in predicting brain volumes and WMLs were also investigated.

RESULTS

On average, higher baseline dietary Mg intake was associated with larger brain volumes (gray matter [GM]: 0.001% [SE = 0.0003]; left hippocampus [LHC]: 0.0013% [SE = 0.0006]; and right hippocampus [RHC]: 0.0023% [SE = 0.0006]) in both men and women. Latent class analysis of Mg intake revealed three classes: "high-decreasing" (men = 3.2%, women = 1.9%), "low-increasing" (men = 1.09%, women = 1.62%), and "stable normal" (men = 95.71%, women = 96.51%). In women, only the "high-decreasing" trajectory was significantly associated with larger brain volumes (GM: 1.17%, [SE = 0.58]; and RHC: 2.79% [SE = 1.11]) compared to the "normal-stable", the "low-increasing" trajectory was associated with smaller brain volumes (GM: - 1.67%, [SE = 0.30]; white matter [WM]: - 0.85% [SE = 0.42]; LHC: - 2.43% [SE = 0.59]; and RHC: - 1.50% [SE = 0.57]) and larger WMLs (1.6% [SE = 0.53]). Associations between Mg and BP measures were mostly non-significant. Furthermore, the observed neuroprotective effect of higher dietary Mg intake in the "high-decreasing" trajectory appears to be greater in post-menopausal than pre-menopausal women.

CONCLUSIONS

Higher dietary Mg intake is related to better brain health in the general population, and particularly in women.

Nutrients and Dementia: Prospective Study

The association of diet and nutrients with dementia risk is an interesting research topic. Middle-aged and older Europeans not diagnosed with dementia within two years of baseline were followed up and their data were analysed until 2021. The association between the nutrient quintiles measured by the web-based 24 h dietary and the risk of developing dementia was examined using a Cox proportional hazard model after adjusting for potential confounding factors. Approximately 160,000 subjects and 1200 cases were included in the analysis of each nutrient. A greater risk of dementia was associated with (a) no alcohol intake (compared with moderate to higher intake), (b) higher intake of total sugars and carbohydrates (compared with lower intake), (c) highest or lowest fat intake (compared with moderate intake), (d) quintiles of highest or lowest magnesium intake (compared with the quintile of the second highest intake), and (e) highest protein intake (compared with moderate intake). Overall, the present results are congruent with the importance of a moderate intake of certain nutrients.

Dietary Intake Levels of Iron, Copper, Zinc, and Manganese in Relation to Cognitive Function: A Cross-Sectional Study

Background: Previous studies have related circulating levels of trace metal elements, of which dietary intake is the major source, to cognitive outcomes. However, there are still relatively few studies evaluating the associations of dietary intake levels of iron, copper, zinc, and manganese with cognitive function (CF). Methods: We leveraged the data of 6863 participants (mean [standard deviation] age = 66.7 [10.5] years) in the Health and Retirement Study (2013/2014). Dietary intake levels of iron, copper, zinc, and manganese were calculated from a semi-quantitative food frequency questionnaire. CF was assessed using the 27-point modified Telephone Interview for Cognitive Status (TICS). We used linear regression models to calculate the mean differences in global CF scores by quintiles of dietary intake levels of trace metal elements. Results: Among the study participants, the mean (SD) values of daily dietary intake were 13.3 (6.3) mg for iron, 1.4 (0.7) mg for copper, 10.7 (4.6) mg for zinc, and 3.3 (1.6) mg for manganese. Compared with the lowest quintile of dietary iron intake (<8.1 mg), the highest quintile (≥17.7 mg) was associated with a lower cognitive score (-0.50, -0.94 to -0.06, P-trend = 0.007). Higher dietary copper was significantly associated with poorer CF (P-trend = 0.002), and the mean difference in cognitive score between extreme quintiles (≥1.8 vs. <0.8 mg) was -0.52 (95% confidence interval: -0.94 to -0.10) points. We did not observe significant associations for dietary intake of zinc (P-trend = 0.785) and manganese (P-trend = 0.368). Conclusion: In this cross-sectional study, higher dietary intake of iron and copper was related to worse CF, but zinc and manganese intake levels were not significantly associated with CF.

Magnesium and the Brain: A Focus on Neuroinflammation and Neurodegeneration

Magnesium (Mg) is involved in the regulation of metabolism and in the maintenance of the homeostasis of all the tissues, including the brain, where it harmonizes nerve signal transmission and preserves the integrity of the blood-brain barrier. Mg deficiency contributes to systemic low-grade inflammation, the common denominator of most diseases. In particular, neuroinflammation is the hallmark of neurodegenerative disorders. Starting from a rapid overview on the role of magnesium in the brain, this narrative review provides evidences linking the derangement of magnesium balance with multiple sclerosis, Alzheimer's, and Parkinson's diseases.

Exploring the K isotope composition of Göttingen minipig brain regions, and implications for Alzheimer's disease

Natural stable metal isotopes have shown utility in differentiation between healthy and diseased brain states (e.g. Alzheimer's disease, AD). While the AD brain accumulates some metals, it purges others, namely K (accompanied by increased serum K, suggesting brain-blood transferal). Here, K isotope compositions of Göttingen minipig brain regions for two AD models at midlife are reported. Results indicate heavy K isotope enrichment where amyloid beta (Aβ) accumulation is observed, and this enrichment correlates with relative K depletion. These results suggest preferential efflux of isotopically light K+ from the brain, a linkage between brain K concentrations and isotope compositions, and linkage to Aβ (previously shown to purge cellular brain K+). Brain K isotope compositions differ from that for serum and brain K is much more abundant than in serum, suggesting that changes in brain K may transfer a measurable K isotope excursion to serum, thereby generating an early AD biomarker.

Dietary calcium and magnesium intake and risk for incident dementia: The Shanghai Aging Study

INTRODUCTION

Calcium (Ca), magnesium (Mg), or the calcium to magnesium (Ca:Mg) ratio may affect the risk of dementia via complex mechanisms. The aim of this study was to evaluate the association of dietary Ca, Mg, and Ca:Mg ratio with dementia risk at the prospective phase of the Shanghai Aging Study.

METHODS

We analyzed data from 1565 dementia-free participants living in an urban community who had measurements of dietary Ca and Mg intake derived from a food frequency questionnaire at baseline and incident dementia during follow-up.

RESULTS

Over the 5-year follow-up, 162 (10.4%) participants were diagnosed with incident dementia by Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria. Participants with the lowest tertile of dietary Ca (<339.1 mg/day) and Mg (<202.1 mg/day) had the highest incidence rates of dementia (3.3/100 person-years for Ca, 3.3/100 person-years for Mg) compared to those with higher Ca and Mg intake. In the subgroup with Ca:Mg ratios ≤ 1.69, Mg intake >267.5 mg/day was related to an increased risk for dementia (adjusted hazard ratio: 3.97, 95% confidence interval: 1.29-12.25).

CONCLUSIONS

Our findings suggest that high dietary intake of Mg is associated with an increased risk of dementia mainly among older adults with low Ca:Mg intake ratios. Proper balance of Ca to Mg in the diet may be critical to the relationship between Mg intake and risk of dementia.

HIGHLIGHTS

Participants with the lowest tertile of dietary calcium (Ca) and magnesium (Mg) had the highest incidence rates of dementia.In the subgroup with Ca:Mg ratios ≤1.69, Mg intake >267.5 mg/day was related to an increased risk for dementia.Balance of Ca to Mg in diet may be critical to the relationship between Mg intake and risk of dementia.

Ca:Mg ratio, medium-chain fatty acids, and the gut microbiome

BACKGROUND & AIMS

Ketogenic medium-chain fatty acids (MCFAs) with profound health benefits are commonly found in dairy products, palm kernel oil and coconut oil. We hypothesize that magnesium (Mg) supplementation leads to enhanced gut microbial production of MCFAs and, in turn, increased circulating MCFAs levels.

METHODS

We tested this hypothesis in the Personalized Prevention of Colorectal Cancer Trial (PPCCT) (NCT01105169), a double-blind 2 × 2 factorial randomized controlled trial enrolling 240 participants. Six 24-h dietary recalls were performed for all participants at the baseline and during the intervention period. Based on the baseline 24-h dietary recalls, the Mg treatment used a personalized dose of Mg supplementation that would reduce the calcium (Ca): Mg intake ratio to around 2.3. We measured plasma MCFAs, sugars, ketone bodies and tricarboxylic acid cycle (TCA cycle) metabolites using the Metabolon's global Precision Metabolomics™ LC-MS platform. Whole-genome shotgun metagenomics (WGS) sequencing was performed to assess microbiota in stool samples, rectal swabs, and rectal biopsies.

RESULTS

Personalized Mg treatment (mean dose 205.58 mg/day with a range from 77.25 to 389.55 mg/day) significantly increased the plasma levels of C7:0, C8:0, and combined C7:0 and C8:0 by 18.45%, 25.28%, and 24.20%, respectively, compared to 14.15%, 10.12%, and 12.62% decreases in the placebo arm. The effects remain significant after adjusting for age, sex, race and baseline level (P = 0.0126, P = 0.0162, and P = 0.0031, respectively) and FDR correction at 0.05 (q = 0.0324 for both C7:0 and C8:0). Mg treatment significantly reduced the plasma level of sucrose compared to the placebo arm (P = 0.0036 for multivariable-adjusted and P = 0.0216 for additional FDR correction model) whereas alterations in daily intakes of sucrose, fructose, glucose, maltose and C8:0 from baseline to the end of trial did not differ between two arms. Mediation analysis showed that combined C7:0 and C8:0 partially mediated the effects of Mg treatment on total and individual ketone bodies (P for indirect effect = 0.0045, 0.0043, and 0.03, respectively). The changes in plasma levels of C7:0 and C8:0 were significantly and positively correlated with the alterations in stool microbiome α diversity (r = 0.51, p = 0.0023 and r = 0.34, p = 0.0497, respectively) as well as in stool abundance for the signatures of MCFAs-related microbiota with acyl-ACP thioesterase gene producing C7:0 (r = 0.46, p = 0.0067) and C8:0 (r = 0.49, p = 0.003), respectively, following Mg treatment.

CONCLUSIONS

Optimizing Ca:Mg intake ratios to around 2.3 through 12-week personalized Mg supplementation leads to increased circulating levels of MCFAs (i.e. C7:0 and C8:0), which is attributed to enhanced production from gut microbial fermentation and, maybe, sucrose consumption.

Dietary supplements in neurological diseases and brain aging

A healthy diet shapes a healthy mind. Diet quality has a strong association with brain health. Diet influences the onset and consequences of neurological diseases, and dietary factors may influence mental health at individual and population level. The link between unhealthy diet, impaired cognitive function and neurodegenerative diseases indicates that adopting a healthy diet would ultimately afford prevention and management of neurological diseases and brain aging. Neurodegenerative diseases are of multifactorial origin and result in progressive loss of neuronal function in the brain, leading to cognitive impairment and motoneuron disorders. The so-called Mediterranean diet (MedDiet) with its healthy ingredients rich in antioxidant, anti-inflammatory, immune, neuroprotective, antidepressant, antistress and senolytic activity plays an essential role in the prevention and management of neurological diseases and inhibits cognitive decline in neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's diseases. The MedDiet also modulates the gut-brain axis by promoting a diversity of gut microbiota. In view of the importance of diet in neurological diseases management, this review focuses on the dietary components, natural compounds and medicinal plants that have proven beneficial in neurological diseases and for brain health. Among them, polyphenols, omega-3 fatty acids, B vitamins and several ayurvedic herbs have promising beneficial effects.

Oral frailty indicators to target major adverse health-related outcomes in older age: a systematic review

A well-preserved oral function is key to accomplishing essential daily tasks. However, in geriatric medicine and gerodontology, as age-related physiological decline disrupts several biological systems pathways, achieving this objective may pose a challenge. We aimed to make a systematic review of the existing literature on the relationships between poor oral health indicators contributing to the oral frailty phenotype, defined as an age-related gradual loss of oral function together with a decline in cognitive and physical functions, and a cluster of major adverse health-related outcomes in older age, including mortality, physical frailty, functional disability, quality of life, hospitalization, and falls. Six different electronic databases were consulted by two independent researchers, who found 68 eligible studies published from database inception to September 10, 2022. The risk of bias was evaluated using the National Institutes of Health Quality Assessment Toolkits for Observational Cohort and Cross-Sectional Studies. The study is registered on PROSPERO (CRD42021241075). Eleven different indicators of oral health were found to be related to adverse outcomes, which we grouped into four different categories: oral health status deterioration; decline in oral motor skills; chewing, swallowing, and saliva disorders; and oral pain. Oral health status deterioration, mostly number of teeth, was most frequently associated with all six adverse health-related outcomes, followed by chewing, swallowing, and saliva disorders associated with mortality, physical frailty, functional disability, hospitalization, and falls, then decline in oral motor skills associated with mortality, physical frailty, functional disability, hospitalization, and quality of life, and finally oral pain was associated only with physical frailty. The present findings could help to assess the contribution of each oral health indicator to the development of major adverse health-related outcomes in older age. These have important implications for prevention, given the potential reversibility of all these factors.

The Role of Obesity and Diabetes in Dementia

Chronic conditions such as obesity, diabetes, and dementia are increasing in the United States (US) population. Knowledge of these chronic conditions, preventative measures, and proper management tactics is important and critical to preventing disease. The overlap between obesity, diabetes, and dementia is becoming further elucidated. These conditions share a similar origin through the components of increasing age, gender, genetic and epigenetic predispositions, depression, and a high-fat Western diet (WD) that all contribute to the inflammatory state associated with the development of obesity, diabetes, and dementia. This inflammatory state leads to the dysregulation of food intake and insulin resistance. Obesity is often the cornerstone that leads to the development of diabetes and, subsequently, in the case of type 2 diabetes mellitus (T2DM), progression to “type 3 diabetes mellitus (T3DM)”. Obesity and depression are closely associated with diabetes. However, dementia can be avoided with lifestyle modifications, by switching to a plant-based diet (e.g., a Mediterranean diet (MD)), and increasing physical activity. Diet and exercise are not the only treatment options. There are several surgical and pharmacological interventions available for prevention. Current and future research within each of these fields is warranted and offers the chance for new treatment options and a better understanding of the pathogenesis of each condition.

Long-term association of vegetable and fruit intake with risk of dementia in Japanese older adults: the Hisayama study

Background

Several prospective Western studies have reported an inverse association of vegetable and fruit intake with dementia risk. However, there is limited epidemiologic evidence in Asians. This study investigated the association of intakes of vegetables, fruits, and their nutrients on the risk of incident dementia and its subtypes in a Japanese community.

Methods

A total of 1071 participants (452 men and 619 women) aged ≥60 years without dementia at baseline were prospectively followed up for 24 years. Intakes of vegetables, fruits, and nutrients were evaluated using a 70-item semiquantitative food frequency questionnaire at baseline and were categorized into quartiles separately by gender. The outcome measure was the development of dementia and its subtypes—namely, Alzheimer’s disease (AD) and vascular dementia (VaD). The risk estimates of incident dementia were computed using a Cox proportional hazards model.

Results

During the long-term follow-up period, 464 subjects developed dementia, of whom 286 had AD and 144 had VaD. Higher vegetable intake was associated gradually with lower risk of developing dementia and AD (both P-trend < 0.05), but not VaD, after adjusting for confounders. Subjects allocated the highest quartile of vegetable intake had 27 and 31% lower risk of dementia and AD, respectively, than those with the lowest quartile. The risk of dementia decreased significantly with higher intakes of vitamin A, riboflavin, vitamin C, magnesium, calcium, and potassium (all P-trend < 0.05). Subjects with higher total dietary fiber intake tended to be at decreased risk for total dementia (P-trend = 0.07). Meanwhile, there were no significant associations between fruit intake and the risk of dementia and its subtypes.

Conclusion

Higher intakes of vegetables and their constituent nutrients were associated with a lower risk of dementia in Japanese older adults. A diet rich in vegetables may be beneficial in reducing the dementia risk in Asians.

Relationship between Urinary Calcium Excretion and Lower Urinary Tract Symptoms

To date, few detailed studies have been conducted on the convenient and useful markers for the prevalence of lower urinary tract symptoms (LUTS), including overactive bladder (OAB) and nocturia. A high level of calcium (Ca) excretion (hypercalciuria) is indicative of lifestyle-related diseases such as hypertension, which are associated with the onset of LUTS. Hence, in this study we attempted to clarify the relationship between urinary Ca excretion and OAB, nocturia, and nocturnal polyuria in adults. The present study showed that patients with hypercalciuria frequently experienced OAB, nocturia, and nocturnal polyuria. In addition, this study revealed that the severity of LUTS is significantly associated with urinary Ca excretion and that hypercalciuria is an important risk factor for OAB, nocturia, and nocturnal polyuria.

Association between magnesium intake and cognition in US older adults: National Health and Nutrition Examination Survey (NHANES) 2011 to 2014

INTRODUCTION

Identifying nutrition- and modifiable lifestyle-based risk factors for cognitive decline and dementia may contribute future primary prevention strategies. This study aimed to evaluate the associations between magnesium intake and cognition in older adults in the United States.

METHODS

Based on the National Health and Nutrition Survey (NHANES) between 2011 and 2014, the study included 2508 participants aged 60 years and older. Linear regression models were used to examine the association of total magnesium intake with cognition.

RESULTS

After adjusted demographic and other confounding factors, intakes of energy and total calcium, and serum vitamin D level, higher intake of total magnesium was independently associated with 0.15 higher global cognitive z-score (95% confidence interval, 0.02 to 0.28 for highest vs. lowest quartile, P trend = .037). The positive association of total magnesium intake with global cognition was primarily presented among women, non-Hispanic Whites, and those with sufficient serum vitamin D levels (≥50 nmol/L), although interactions were not significant. There were no clear linear associations for global cognition with serum vitamin D level.

DISCUSSIONS

Our findings suggest that high magnesium intake alone may improve cognition in older adults, particularly among non-Hispanic Whites and subjects with sufficient levels of serum vitamin D. Further studies are needed to confirm the findings.

Health Effects of Calcium: Evidence From Mendelian Randomization Studies

Calcium is widely used in conjunction with vitamin D to prevent osteoporosis. The use of calcium supplementation is also promoted for its potential benefits in lowering the risk for metabolic syndromes and cancers. However, the causal link between calcium and various health outcomes remains unclear. This review focuses on the evidence from 24 Mendelian randomization (MR) studies that were designed to minimize bias from confounding and reverse causation. These MR studies evaluated the effect of lifelong genetically higher serum calcium levels on various health outcomes. Overall, available MR studies found no conclusive effects of serum calcium levels on bone mineral density and fracture, ischemic stroke and heart failure, cancers, type 2 diabetes, Parkinson disease, or offspring birth weight. However, a higher serum calcium concentration was reported to have estimated causal effects on increased risks for coronary artery disease (especially myocardial infarction), migraine, renal colic, allergy/adverse effect of penicillin, and reduced risks for osteoarthrosis and osteoarthritis. In conclusion, supplementation of calcium in individuals from the general population is not predicted to influence the risk of most investigated diseases to date. Moreover, long-term high serum calcium concentrations may result in adverse health outcomes. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Ca:Mg Ratio, APOE Cytosine Modifications, and Cognitive Function: Results from a Randomized Trial

BACKGROUND

Deterioration of ionized calcium (Ca2+) handling in neurons could lead to neurodegenerative disease. Magnesium (Mg) antagonizes Ca during many physiologic activities, including energy metabolism and catalyzation of demethylation from 5-methylcytosine(5-mC) to 5-hydroxymethylcytosine(5-hmC).

OBJECTIVE

To test the hypothesis that actively reducing the Ca:Mg intake ratio in the diet through Mg supplementation improves cognitive function, and to test whether this effect is partially mediated by modified cytosines in Apolipoprotein E (APOE).

METHODS

This study is nested within the Personalized Prevention of Colorectal Cancer Trial (PPCCT), a double-blind 2×2 factorial randomized controlled trial, which enrolled 250 participants from Vanderbilt University Medical Center. Target doses for both Mg and placebo arms were personalized.

RESULTS

Among those aged > 65 years old who consumed a high Ca:Mg ratio diet, we found that reducing the Ca:Mg ratio to around 2.3 by personalized Mg supplementation significantly improved cognitive function by 9.1% (p = 0.03). We also found that reducing the Ca:Mg ratio significantly reduced 5-mC at the cg13496662 and cg06750524 sites only among those aged > 65 years old (p values = 0.02 and 0.03, respectively). Furthermore, the beneficial effect of reducing the Ca:Mg ratio on cognitive function in those aged over 65 years was partially mediated by reductions in 5-mC levels (i.e., cg13496662 and cg06750524) in APOE (p for indirect effect = 0.05).

CONCLUSION

Our findings suggest that, among those age 65 and over with a high dietary Ca:Mg ratio, optimal Mg status may improve cognitive function partially through modifications in APOE methylation. These findings, if confirmed, have significant implications for the prevention of cognitive aging and Alzheimer's disease.Clinical Trial Registry number and website: #100106 https://clinicaltrials.gov/ct2/show/NCT03265483.

Plasma Concentrations of Magnesium and Risk of Dementia: A General Population Study of 102 648 Individuals

BACKGROUND

Low and high concentrations of plasma magnesium are associated with increased risk of future all-cause dementia; however, the underlying reasons remain elusive. The magnesium ion is an important electrolyte serving as a cofactor in many enzymatic processes in the human organism. Magnesium affects both neuronal and vascular functions. We investigated the associations of plasma concentrations of magnesium associate with common subtypes of dementia as Alzheimer dementia and non-Alzheimer dementia, and potential pathways by which magnesium may affect risk of dementia.

METHODS

Plasma concentrations of magnesium were measured in 102 648 individuals from the Copenhagen General Population Study. Cox regression and natural effects mediation analyses evaluated associations with either Alzheimer dementia or non-Alzheimer dementia.

RESULTS

Multifactorially adjusted hazard ratios for non-Alzheimer dementia were 1.50(95% confidence interval (CI):1.21-1.87) for the lowest and 1.34(1.07-1.69) for the highest vs the fourth quintile (reference) of plasma magnesium concentrations. Diabetes, cumulated smoking, stroke, and systolic blood pressure mediated 10.4%(3.1-22.8%), 6.8%(1.2-14.0%), 1.3%(0.1-3.6%), and 1.0%(0.2-2.6%), respectively, in the lowest quintile, whereas stroke mediated 3.2%(0.4-11.9%) in the highest quintile. No associations were observed for Alzheimer dementia.

CONCLUSIONS

Low and high plasma magnesium concentrations were associated with high risk of vascular-related non-Alzheimer dementia, with the lowest risk observed at a concentration of 2.07 mg/dL (0.85 mmol/L). No association was observed for Alzheimer dementia. Mediation analysis suggested that diabetes may be in the causal pathway between low plasma magnesium concentrations and high risk of non-Alzheimer dementia, while cumulated smoking, stroke, and systolic blood pressure played minor mediating roles.

Association between 24-h urinary sodium to potassium ratio and mild cognitive impairment in community-based general population

OBJECTIVE

To explore the relationship between parameters of Na and K excretion using 24-h urine sample and mild cognitive impairment (MCI) in general population.

DESIGN

This is a cross-sectional study.

SETTING

Community-based general population in Emin China.

PARTICIPANTS

Totally, 1147 subjects aged ≥18 years were selected to complete the study, with a multistage proportional random sampling method. Cognitive status was assessed with Mini Mental State Examination (MMSE) questionnaire and timed 24-h urine specimens were collected. Finally, 561 participants aged ≥35 years with complete urine sample and MMSE data were included for the current analysis and divided into groups by tertiles of 24-h urinary sodium to potassium ratio (24-h UNa/K) as lowest (T1), middle (T2) and highest (T3) groups.

RESULTS

The MMSE score was significantly lower in T3, compared with the T1 group (26·0 v. 25·0, P = 0·002), and the prevalent MCI was significantly higher in T3 than in T1 group (11·7 % v. 25·8 %, P < 0·001). In multiple linear regression, 24-UNa/K (β: -0·184, 95 % CI -0·319, -0·050, P = 0·007) was negatively associated with MMSE score. In multivariable logistic regression, compared with T1 group, 24-h UNa/K in the T2 and T3 groups showed 2·01 (95 % CI 1·03, 3·93, P = 0·041) and 3·38 (95 % CI 1·77, 6·44, P < 0·001) fold odds for presence of MCI, even after adjustment for confounders. More augmented results were demonstrated in sensitivity analysis by excluding individuals taking anti-hypertensive agents.

CONCLUSIONS

Higher 24-h UNa/K is in an independent association with prevalent MCI.

A Fundamental Role for Oxidants and Intracellular Calcium Signals in Alzheimer's Pathogenesis-And How a Comprehensive Antioxidant Strategy May Aid Prevention of This Disorder

Oxidative stress and increased cytoplasmic calcium are key mediators of the detrimental effects on neuronal function and survival in Alzheimer's disease (AD). Pathways whereby these perturbations arise, and then prevent dendritic spine formation, promote tau hyperphosphorylation, further amplify amyloid β generation, and induce neuronal apoptosis, are described. A comprehensive program of nutraceutical supplementation, comprised of the NADPH oxidase inhibitor phycocyanobilin, phase two inducers, the mitochondrial antioxidant astaxanthin, and the glutathione precursor N-acetylcysteine, may have important potential for antagonizing the toxic effects of amyloid β on neurons and thereby aiding prevention of AD. Moreover, nutraceutical antioxidant strategies may oppose the adverse impact of amyloid β oligomers on astrocyte clearance of glutamate, and on the ability of brain capillaries to export amyloid β monomers/oligomers from the brain. Antioxidants, docosahexaenoic acid (DHA), and vitamin D, have potential for suppressing microglial production of interleukin-1β, which potentiates the neurotoxicity of amyloid β. Epidemiology suggests that a health-promoting lifestyle, incorporating a prudent diet, regular vigorous exercise, and other feasible measures, can cut the high risk for AD among the elderly by up to 60%. Conceivably, complementing such lifestyle measures with long-term adherence to the sort of nutraceutical regimen outlined here may drive down risk for AD even further.

Association of magnesium intake and vitamin D status with cognitive function in older adults: an analysis of US National Health and Nutrition Examination Survey (NHANES) 2011 to 2014

PURPOSE

Reduced cognitive function associated with aging has gained increasing attention as the US population ages. Magnesium plays a critical role in vitamin D biosynthesis and metabolism; and deficiencies in magnesium and vitamin D show associations with poor cognition. However, no study has examined their interaction. This study aimed to evaluate the associations of magnesium intake and serum 25-hydroxyvitamin D (25(OH)D) concentrations, indicating vitamin D status, with cognition, and interaction between these nutrients in older adults.

METHODS

Based on the National Health and Nutrition Survey (NHANES) 2011-2014, the study included 2466 participants aged ≥ 60 years who completed the Digit Symbol Substitution Test (DSST) and had data available on serum 25(OH)D and magnesium intake. Cognitive impairment was defined as a DSST score lower than the lowest quartile. Serum 25(OH)D concentrations were measured by HPLC-tandem mass spectrometry.

RESULTS

Higher total magnesium intake was independently associated with higher DSST scores (highest quartile vs lowest: β = 4.34, 95% CI 1.14-7.54). The association of total magnesium intake with high DSST score was primarily observed among women, non-Hispanic whites, physically active participants and those with sufficient vitamin D status, although the interactions were not significant. The odds of cognitive impairment was reduced with increasing intake of total magnesium (p trend < 0.01) and higher level of serum 25(OH)D (p trend = 0.05).

CONCLUSIONS

Findings suggest that high magnesium intake alone may improve cognitive function in older adults, and the association may be stronger among subjects with sufficient vitamin D status. Further studies are needed to confirm these findings.

Magnesium in Aging, Health and Diseases

Several changes of magnesium (Mg) metabolism have been reported with aging, including diminished Mg intake, impaired intestinal Mg absorption and renal Mg wasting. Mild Mg deficits are generally asymptomatic and clinical signs are usually non-specific or absent. Asthenia, sleep disorders, hyperemotionality, and cognitive disorders are common in the elderly with mild Mg deficit, and may be often confused with age-related symptoms. Chronic Mg deficits increase the production of free radicals which have been implicated in the development of several chronic age-related disorders. Numerous human diseases have been associated with Mg deficits, including cardiovascular diseases, hypertension and stroke, cardio-metabolic syndrome and type 2 diabetes mellitus, airways constrictive syndromes and asthma, depression, stress-related conditions and psychiatric disorders, Alzheimer's disease (AD) and other dementia syndromes, muscular diseases (muscle pain, chronic fatigue, and fibromyalgia), bone fragility, and cancer. Dietary Mg and/or Mg consumed in drinking water (generally more bioavailable than Mg contained in food) or in alternative Mg supplements should be taken into consideration in the correction of Mg deficits. Maintaining an optimal Mg balance all through life may help in the prevention of oxidative stress and chronic conditions associated with aging. This needs to be demonstrated by future studies.

Low Serum Magnesium is Associated with Incident Dementia in the ARIC-NCS Cohort

Higher serum magnesium is associated with lower risk of multiple morbidities, including diabetes, stroke, and atrial fibrillation, but its potential neuroprotective properties have also been gaining traction in cognitive function and decline research. We studied 12,040 participants presumed free of dementia in the Atherosclerosis Risk in Communities (ARIC) study. Serum magnesium was measured in fasting blood samples collected in 1990–1992. Dementia status was ascertained through cognitive examinations in 2011–2013, 2016–2017, and 2018–2019, along with informant interviews and indicators of dementia-related hospitalization events and death. Participants’ cognitive functioning capabilities were assessed up to five times between 1990–1992 and 2018–2019. The cognitive function of participants who did not attend follow-up study visits was imputed to account for attrition. We identified 2519 cases of dementia over a median follow-up period of 24.2 years. The lowest quintile of serum magnesium was associated with a 24% higher rate of incident dementia compared to those in the highest quintile of magnesium (HR, 1.24; 95% CI, 1.07, 1.44). No relationship was found between serum magnesium and cognitive decline in any cognitive domain. Low midlife serum magnesium is associated with increased risk of incident dementia, but does not appear to impact rates of cognitive decline.

Association Between Serum Magnesium Levels and Alzheimer's Disease or Mixed Dementia Patients: A Population-Based Retrospective Controlled Study

Background

High magnesium intake has been associated with a decreased risk of dementia. In contrast, other research has found that both low and high serum magnesium levels were associated with an increased risk of Alzheimer's disease and mixed dementia. Hence, presently the role of magnesium levels in dementia is unclear.

Objective

To investigate a possible association between serum magnesium concentrations and dementia in a large population-based sample.

Methods

Maccabi Healthcare Service in Israel provides healthcare to over 2 million citizens. Maccabi maintains a registry with approximately 26,000 diagnosed dementia patients. We focused on patients of both sexes with Alzheimer's disease or mixed dementia aged 65 or older, excluding patients with clinical diagnoses that could affect serum magnesium level, or with other causes of cognitive decline. Our control group consisted of patients of the same age and sex without dementia.

Results

No significant differences were found in mean, mode, and median magnesium levels between the dementia and control groups. However, there were marginally but significantly more cases with low magnesium levels among dementia patients than among controls: A total of 9.4% of tests done in patients with dementia and 7.81% done in non-dementia subjects were hypomagnesemic (p <  0.00001).

Conclusion

Despite similar means and medians of serum magnesium in dementia and controls, the proportion of lower than normal magnesium test results was slightly higher among dementia patients. It is possible that patients with dementia have more episodes of hypomagnesemia than controls, despite similar overall mean levels of magnesium.

A study of the association between cognitive abilities and dietary intake in young women

BACKGROUND

Cognitive abilities comprise activities that relate to receiving and responding to information from the environment, internal processing, making complex decisions, and then responding to this in the context of behavior.

AIM

The current study investigated the association between dietary intake and seven aspects of cognitive abilities among healthy young women.

METHODS

The study was carried out among 182 women aged 18-25 years. A valid and reliable food frequency questionnaire containing 65 food items was used to estimate dietary intake. Neuropsychological function and cognitive abilities of participants were determined using standard questionnaires.

RESULTS

Significant differences were found in depression, anxiety, stress, physical, and mental health-related quality of life as well as daytime sleepiness for the participants in different quartiles of cognitive abilities score (p<0.05). Participants in the fourth quartile of cognitive abilities score consumed significantly higher energy, carbohydrate, protein, calcium, iron, zinc, vitamin A, thiamin, and riboflavin compared to those in the lowest quartile (p<0.05). There were strong correlations between total cognitive abilities score and dietary sodium, calcium, phosphorus, and thiamin (p<0.05). Using stepwise multiple linear regression analysis, iron and thiamin were statistically significant factors for the prediction of cognitive abilities.

CONCLUSIONS

These findings demonstrate that neurocognitive function is related to dietary macro and micronutrients including energy, carbohydrate, protein, calcium, iron, zinc, vitamin A, thiamin, and riboflavin on cognitive performance among young women without memory deficit.

Relationship Between Calcium Intake and Impaired Activities of Daily Living in a Japanese Population: NIPPON DATA90

Background

Major reasons for long-term care insurance certification in Japan are stroke, dementia, and fracture. These diseases are reported to be associated with calcium intake. This study examined the association between calcium intake and impaired activities of daily living (ADL) using the data from NIPPON DATA90, consisting of representative sample of the Japanese population.

Methods

A population-based nested case-control study was performed. A baseline survey was conducted in 1990, followed by ADL surveys of individuals ≥65 years old in 2000. Individuals with impaired ADL and selected age- and sex-matched controls were then identified. We obtained 132 pairs. Calcium intake was energy-adjusted using the residual method. The association between calcium intake and impaired ADL was examined using conditional logistic regression models. To assess the accuracy of the estimates, we conducted bootstrap analyses.

Results

The adjusted odds ratios (ORs) for impaired ADL compared with the group with a calcium intake of <476 mg/day were 0.72 (95% confidence interval [CI], 0.37–1.40) for the 476–606 mg/day group and 0.44 (95% CI, 0.21–0.94) for the ≥607 mg/day group in 2000 (P for linear trend = 0.03). After the bootstrap analyses, the inverse relationship unchanged (median OR per 100-mg rise in calcium intake, 0.87 [1,000 resamplings]; 95% CI, 0.76–0.97).

Conclusions

After bootstrap analyses, calcium intake was inversely associated with impaired ADL 10 years after the baseline survey.

Lifestyle Modifications and Nutritional Interventions in Aging-Associated Cognitive Decline and Alzheimer's Disease

Alzheimer's disease (AD) is a type of incurable neurodegenerative disease that is characterized by the accumulation of amyloid-β (Aβ; plaques) and tau hyperphosphorylation as neurofibrillary tangles (NFTs) in the brain followed by neuronal death, cognitive decline, and memory loss. The high prevalence of AD in the developed world has become a major public health challenge associated with social and economic burdens on individuals and society. Due to there being limited options for early diagnosis and determining the exact pathophysiology of AD, finding effective therapeutic strategies has become a great challenge. Several possible risk factors associated with AD pathology have been identified; however, their roles are still inconclusive. Recent clinical trials of the drugs targeting Aβ and tau have failed to find a cure for the AD pathology. Therefore, effective preventive strategies should be followed to reduce the exponential increase in the prevalence of cognitive decline and dementia, especially AD. Although the search for new therapeutic targets is a great challenge for the scientific community, the roles of lifestyle interventions and nutraceuticals in the prevention of many metabolic and neurodegenerative diseases are highly appreciated in the literature. In this article, we summarize the molecular mechanisms involved in AD pathology and the possible ameliorative action of lifestyle and nutritional interventions including diet, exercise, Calorie restriction (CR), and various bioactive compounds on cognitive decline and dementia. This article will provide insights into the role of non-pharmacologic interventions in the modulation of AD pathology, which may offer the benefit of improving quality of life by reducing cognitive decline and incident AD.

Relations of magnesium intake to cognitive impairment and dementia among participants in the Women's Health Initiative Memory Study: a prospective cohort study

OBJECTIVE

To examine the associations of dietary and supplemental magnesium (Mg) as assessed by a semi-quantitative food frequency questionnaire with cognitive outcomes among ageing women.

DESIGN

This work conducts a prospective cohort study of participants enrolled in the Women's Health Initiative Memory Study (WHIMS), which was subsequently extended and named WHIMS-Epidemiology of Cognitive Health.

SETTING

Forty clinical centres in the USA.

PARTICIPANTS

Postmenopausal women aged 65-79 years without dementia on enrolment.

MAIN OUTCOME MEASURES

Physician-adjudicated mild cognitive impairment (MCI) and/or probable dementia (PD).

RESULTS

Participants were excluded (n=1006) if they had extreme values of dietary energy intake, had missing or extreme body mass index values, with prevalent MCI/PD at baseline, received only one cognitive assessment or had been followed up for <1 year. During >20 years of follow-up, 765 (11.8%) out of 6473 participants developed MCI/PD. For MCI/PD and MCI, the risks tended to be lower among participants in quintiles Q2-Q5 of Mg consumption compared with those in the lowest quintile. Participants in Q3 had a significantly lower risk of MCI/PD (HR 0.69, 95% CI 0.53 to 0.91) and MCI (HR 0.63, 95% CI 0.45 to 0.87) after multivariate adjustments. No significant association was observed between total Mg intake and PD. The association between total Mg intake, MCI/PD and MCI was non-linear as suggested by the likelihood test.

CONCLUSIONS

Total Mg intake between the estimated average requirement and the recommended dietary allowances may associate with a lower risk of MCI/PD and MCI.

TRIAL REGISTRATION NUMBER

NCT00685009.

Anabolic effects of vitamin D and magnesium in aging bone

Decreased bone mass and an increased risk of bone fractures become more common with age. This condition is often associated with osteoporosis and is caused by an imbalance of bone resorption and new bone formation. Lifestyle factors that affect the risk of osteoporosis include alcohol, diet, hormones, physical activity, and smoking. Calcium and vitamin D are particularly important for the age-related loss of bone density and skeletal muscle mass, but other minerals, such as magnesium, also have an important role. Here, we summarize how optimal magnesium and vitamin D balance improve health outcomes in the elderly, the role of magnesium and vitamin D on bone formation, and the implications of widespread deficiency of these factors in the United States and worldwide, particularly in the elderly population.

Association Between Serum β-Alanine and Risk of Dementia

We examined the association between serum concentrations of β-alanine, a metabolite of carnosine and anserine, and the risk of dementia in a general population of elderly Japanese persons. In 2007, 1,475 residents of Hisayama, Japan, aged 60-79 years and without dementia were divided into 4 groups according to quartiles of serum β-alanine concentrations (quartile 1, lowest; quartile 4, highest) and followed for a median of 5.3 years. During follow-up, 117 subjects developed all-cause dementia (Alzheimer in 77 cases and vascular dementia in 31). The risk of all-cause dementia decreased with increasing serum β-alanine levels after adjustment for potential confounding factors (quartile 2, hazard ratio (HR) = 0.73 (95% confidence interval (CI): 0.45, 1.18); quartile 3, HR = 0.50 (95% CI: 0.28, 0.89); quartile 4, HR = 0.50 (95% CI: 0.27, 0.92); P = 0.01 for trend). A similar inverse association was observed for Alzheimer disease (quartile 2, HR = 0.78 (95% CI: 0.44, 1.38); quartile 3, HR = 0.53 (95% CI: 0.26, 1.06); quartile 4, HR = 0.53 (95% CI: 0.25, 1.10); P = 0.04 for trend) but not for vascular dementia. We found that higher serum β-alanine levels were significantly associated with lower risks of all-cause dementia and Alzheimer disease. Because serum β-alanine levels reflect intakes of carnosine/anserine, higher intakes of carnosine/anserine might be beneficial for the prevention of dementia.

Risk Factors Associated with Cortical Thickness and White Matter Hyperintensities in Dementia Free Okinawan Elderly

Background:

Cortical gray matter (GM) and white matter (WM) deterioration are signals of neurodegeneration and increased dementia risk; however, their specific etiologies in dementia-free aging is unclear.

Objective:

The objective of this study was to examine potentially modifiable risk factors of GM and WM degeneration in a well-characterized cohort of dementia-free elderly.

Methods:

96 Okinawan elderly participants (age 83.6) from the Keys to Optimal Cognitive Aging Project (KOCOA) underwent MRI and cognitive evaluation. Serum markers of inflammation (interleukin-6 (IL-6), high sensitivity C-reactive protein), cerebrovascular disease (systolic blood pressure (SBP) 140+, hemoglobin A1C (HgbA1C), total cholesterol), and essential minerals (copper (Cu), magnesium, and calcium) were examined in relation to mean cortical thickness (MCT) and white matter hyperintensities (WMH), adjusting for age and gender. Voxel-based morphometry (VBM) analyses identified relationships between regional GM density and the above markers.

Results:

Decreased MCT was associated with SBP 140 + (p = 0.029) and increased serum IL-6 (p = 0.036), HgbA1C (p = 0.002), and Cu (p = 0.025). In VBM analyses, increased IL-6, HgbA1C, and Cu were associated with decreased GM density in temporal lobe regions. HgbA1C (p = 0.004) was associated with greater WMH volume.

Conclusions:

Peripheral markers of Cu, CVD risk, and inflammation are associated with MRI-markers of decreased brain health in dementia-free Okinawan elderly, with regional cortical thinning in areas involved in early accumulation of Alzheimer’s disease pathology. Results identify potentially modifiable biomarkers as targets in the prevention of dementia in older individuals.

Dairy, soy, and calcium consumption and risk of cognitive impairment: the Singapore Chinese Health Study

PURPOSE

It is unclear if midlife consumption of dairy and soy food intake, and their components of calcium and isoflavones (in soy), is related to cognitive impairment in elderly.

METHODS

We used baseline data on lifestyle and habitual diet of 16,948 participants collected during their recruitment into the Singapore Chinese Health Study from 1993 to 1998, and data on their cognitive function, measured using a 30-item Singapore modified Mini-Mental State Examination, during follow-up interviews from 2014 to 2016. We used multivariable logistic regression models to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for developing cognitive impairment.

RESULTS

Higher dairy intake was associated with a lower risk of cognitive impairment in a dose-dependent manner (P for trend = 0.009). Compared to the lowest quartile of dairy intake, ORs (95% CIs) were 0.93 (0.81-1.07) for the second, 0.88 (0.76-1.01) for the third, and 0.82 (0.72-0.94) for the fourth quartiles of intake. Similar results were found for dairy calcium intake (P for trend = 0.008). However, there was no statistically significant association for intake of soy (OR comparing extreme quartiles 0.99, 95% CI 0.87-1.14, P for trend = 0.92), isoflavones (OR 1.01, 95% CI 0.88-1.15, P for trend = 0.90) or non-dairy calcium (OR 1.06, 95% CI 0.86-1.30, P for trend = 0.81) with risk of cognitive impairment.

CONCLUSIONS

Dairy intake at midlife could have a protective association against cognitive impairment that may not be attributed to its calcium content alone, while soy or isoflavone intake was not associated with the cognition of elderly in our study.