Ten-year trends in vitamin intake in free-living healthy elderly people: the risk of subclinical malnutrition

Nutritional Challenges in Nursing Homes: Pilot Study on Macronutrient Intake and Status of Vitamins D and B12

Older adults living in nursing homes (NH) are considered a population group that could be at risk in terms of nutrition, even more so than their community-dwelling peers. Evidence on the nutritional status of NH residents is scarce, as they are commonly excluded from population-based dietary studies. This is also the case in Slovenia. In the presented pilot study, we assessed the intake of macronutrients as well as the intake and status of vitamin D and vitamin B12 on a sample of NH and NH daycare center users to explore the need for a larger representative study. The pilot study included 37 participants from three Slovenian NH (20 participants) and their daycare centers (17 participants). Daycare centers offer daytime care services for older adults, where users are also provided with major meals during their stay. Intakes of energy and nutrients were estimated by three 24 h dietary records. Fasting blood samples were collected for the assessment of vitamin D and vitamin B12 status. Over 90% of the participants had daily energy and protein intakes below recommendations (reference values: energy intake: males 2100 kcal and females 1700 kcal; protein intake > 1 g/kg body mass). The males' median daily intakes of vitamin D were 1.7 µg (1.5 µg females), and 2.3 µg for vitamin B12 (2.0 µg females). None of the participants had adequate vitamin D intake (>20 µg), and 92.3% males and 87.5% females had inadequate vitamin B12 intake (<4 µg). The prevalence of vitamin D deficiency (serum 25-OH-D conc. < 30 nmol/L) was 100% among NH residents and 53% among NH daycare center users. The prevalence of vitamin B12 deficiency was found in 20% of NH residents. The study results highlighted that certain nutrients might be critical in this population, especially among NH residents; however, a more thorough investigation with the inclusion of other important markers of nutritional status should be performed on a larger, representative sample to support the development and implementation of appropriate public health interventions.

Dietary micronutrient adequacies and adherence to the Mediterranean diet in a population of older adults with type 2 diabetes: A cross-sectional study

BACKGROUND AND AIMS

There are few data on micronutrient intake in older adults with type 2 diabetes (T2D) and their adherence to the Mediterranean diet, a dietary pattern rich in micronutrients. In this cross-sectional study, we evaluated the prevalence of adequacy in micronutrient intake according to the recommendations, and the adherence to the Mediterranean diet in older adults with T2D.

METHODS

One hundred thirty-eight patients (47 women and 91 men) with T2D aged over 65 years were included. Dietary habits were assessed by three 24-h dietary recalls. The micronutrient intake, expressed as mean daily intake, and adequacy were compared with the dietary recommendations proposed by the Italian Society of Human Nutrition (LARN) and the European Food Safety Agency (EFSA). Adherence to the Mediterranean diet was evaluated by the MEDI-quest score.

RESULTS

An extremely low proportion of participants (∼1%) adhered to the recommendations for potassium and vitamin D intake. A low proportion of participants adhered to the recommendations for calcium (∼23%), magnesium (∼16%), selenium (∼17%), vitamin E (∼14%), riboflavin (∼28%), vitamin B6 (∼29%), folate (∼25%), and niacin (∼27%) intake. More than 60% of the population adhered to the recommendations for iron, copper, vitamin A and B12 intake. Only 53% of the population showed high adherence to the Mediterranean diet.

CONCLUSIONS

Our data indicate that a very low proportion of older adults with T2D meet the recommendations for ten micronutrients (calcium, potassium, magnesium, selenium, vitamin D, vitamin E, riboflavin, vitamin B6, folate, and niacin) with an unsatisfactory adherence to the Mediterranean diet. Nutritional approaches aimed at favoring adherence to dietary recommendations and increasing the consumption of foods rich in micronutrients should be implemented in older adults.

Age-related changes in the parameters of carbohydrate metabolism and supply of vitamins B1, B2 in residents of two northern regions

A great deal of research was being done in studying of the age-related characteristics of carbohydrate metabolism and the provision of vitamins B1, B2 among the population of the Subarctic (SR) and Arctic (AR) regions, differing in the extreme natural and climatic-geographic living conditions. The surveyed population was divided into five age groups: 16-21, 22-35, 36-45, 46-60 and 61-74 years old. The parameters of carbohydrate metabolism (glucose, lactate, pyruvate) were determined in the blood serum, the content of thiamine (thiamin diphosphate effect) and riboflavin - in hemolysates, and the values of the lactate/pyruvate ratio (Lac/Pyr) were calculated. Statistical data processing was performed by nonparametric methods. An increase in glucose levels was found in persons of older age groups. Age-related fluctuations of metabolites of carbohydrate metabolism were manifested by a lower content of lactate and the value of the Lac/Pyr ratio in persons aged 16-21 years. Regardless of the age and region of the survey, there were revealed high lactate concentrations, Lac/Pyr values and reduced pyruvate levels, as well as low glucose levels in group aged 16-21 year in AR. For vitamins B1, B2, no pronounced age-related changes were observed, while the content of riboflavin was higher in persons of SR. Moderate hypovitaminosis of thiamin was detected in 13-20,1% and 6,1-22,7% of cases in SR and AR, pronounced - 8,3-11,6% and 4,6-23,5%, respectively, vitamin B2 deficiency was noted in 19,4-23,9% of persons in the AR and in 33,8-42,9% of persons in the AR. Vitamins in both regions at different age periods contributed to the formation of levels of indicators of carbohydrate metabolism: glucose and pyruvate in SR, lactate in AR.

Exploring trajectories in dietary adequacy of the B vitamins folate, riboflavin, vitamins B6 and B12, with advancing older age: a systematic review

Maintaining nutritional adequacy contributes to successful ageing. B vitamins involved in one-carbon metabolism regulation (folate, riboflavin, vitamins B6 and B12) are critical nutrients contributing to homocysteine and epigenetic regulation. Although cross-sectional B vitamin intake in ageing populations is characterised, longitudinal changes are infrequently reported. This systematic review explores age-related changes in dietary adequacy of folate, riboflavin, vitamins B6 and B12 in community-dwelling older adults (≥65 years at follow-up). Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, databases (MEDLINE, Embase, BIOSIS, CINAHL) were systematically screened, yielding 1579 records; eight studies were included (n 3119 participants, 2–25 years of follow-up). Quality assessment (modified Newcastle–Ottawa quality scale) rated all of moderate–high quality. The estimated average requirement cut-point method estimated the baseline and follow-up population prevalence of dietary inadequacy. Riboflavin (seven studies, n 1953) inadequacy progressively increased with age; the prevalence of inadequacy increased from baseline by up to 22·6 and 9·3 % in males and females, respectively. Dietary folate adequacy (three studies, n 2321) improved in two studies (by up to 22·4 %), but the third showed increasing (8·1 %) inadequacy. Evidence was similarly limited (two studies, respectively) and inconsistent for vitamins B6 (n 559; −9·9 to 47·9 %) and B12 (n 1410; −4·6 to 7·2 %). This review emphasises the scarcity of evidence regarding micronutrient intake changes with age, highlighting the demand for improved reporting of longitudinal changes in nutrient intake that can better direct micronutrient recommendations for older adults. This review was registered with PROSPERO (CRD42018104364).

Changes in micronutrient intake and factors associated with this change among older Australian men: the Concord Health and Ageing in Men Project

OBJECTIVES

To examine changes in micronutrient intake over 3 years and identify any associations between socio-economic, health, lifestyle and meal-related factors and these changes in micronutrient intakes among older men.

DESIGN

Prospective study.

SETTING

Dietary adequacy of individual micronutrient was compared to the estimated average requirement of the nutrient reference values (NRV). Attainment of the NRV for twelve micronutrients was incorporated into a dichotomised variable 'not meeting' (meeting ≤ 6) or 'meeting' (meeting ≥ 7) and categorised into four categories to assess change in micronutrient intake over 3 years. The multinomial logistic regression analyses were conducted to model predictors of changes in micronutrient intake.

PARTICIPANTS

Seven hundred and ninety-four men participated in a detailed diet history interview at the third wave (baseline nutrition) and 718 men participated at the fourth wave (3-year follow-up).

RESULTS

The mean age was 81 years (range 75-99 years). Median intakes of the majority of micronutrients decreased significantly over a 3-year follow-up. Inadequacy of the NRV for thiamine, dietary folate, Zn, Mg, Ca and I were significantly increased at a 3-year follow-up than baseline nutrition. The incidence of inadequate micronutrient intake was 21 % and remained inadequate micronutrient intake was 16·4 % at 3-year follow-up. Changes in micronutrient intakes were significantly associated with participants born in the UK and Italy, low levels of physical activity, having ≥2 medical conditions and used meal services.

CONCLUSIONS

Micronutrient intake decreases with age in older men. Our results suggest that strategies to improve some of the suboptimal micronutrient intakes might need to be developed and implemented for older men.

Diet quality and nutrient density in subjects with metabolic syndrome: Influence of socioeconomic status and lifestyle factors. A cross-sectional assessment in the PREDIMED-Plus study

BACKGROUND

Socioeconomic disparities and lifestyle factors are likely to determine the overall quality of the diet. In addition, overeating is compatible with inadequate micronutrient intake and it can lead to adverse health outcomes.

OBJECTIVE

To assess adequacy of dietary nutrient intake and to investigate the influence of socioeconomic and lifestyle factors on nutrient density in a large primary cardiovascular prevention trial conducted in healthy participants with metabolic syndrome (MetS) to assess the cardiovascular effects of an energy-restricted Mediterranean diet (PREDIMED-Plus).

METHODS

Baseline cross-sectional analysis of the PREDIMED-Plus trial with 6646 Spanish participants (aged 55-75 years in men and 60-75 years in women) with overweight/obesity and MetS. Energy and nutrient intake (for 10 nutrients) were calculated using a validated 143-item Food Frequency Questionnaire (FFQ) and nutrient density was estimated dividing the absolute nutrient intake by total energy intake. The prevalence of inadequate intake was estimated according to dietary reference intakes. Multivariable linear regression models were fitted to examine associations between socioeconomic status or lifestyle factors and nutrient density.

RESULTS

A considerable proportion of the screened participants showed a deficient intake of vitamins A, D, E, B₉, calcium, magnesium and dietary fibre. Inadequate intake of four or more of the ten nutrients considered was present in 17% of participants. A higher nutrient density was directly and significantly associated with female sex, higher educational level and a better adherence to the Mediterranean diet. Lifestyle factors such as non-smoking and avoidance of sedentary lifestyles were also independently associated with better nutrient density.

CONCLUSIONS

Patients with MetS, despite being overweight, exhibited suboptimal nutrient intake, especially among men. Low nutrient density diet can be largely explained by differences in socioeconomic and lifestyle factors. These results highlight the importance of focussing on nutritional education in vulnerable populations, taking into account nutrient requirements.

Low vitamin intake is associated with risk of frailty in older adults

Background

the association between vitamin intake and frailty has hardly been studied. The objective was to assess the association of dietary vitamin intake with incident frailty in older adults from Spain.

Methods

data came from a cohort of 1,643 community-dwelling individuals aged ≥65, recruited in 2008-10 and followed up prospectively throughout 2012. At baseline, 10 vitamins were assessed (vitamin A, thiamine, riboflavin, niacin, vitamins B6, B12, C, D, E and folates) using a validated face-to-face diet history. Incident frailty was identified using Fried's definition as having ≥3 of the following five criteria: unintentional weight loss of ≥4.5 kg, exhaustion, weakness, slow walking speed and low physical activity. Nonadherence to the recommended dietary allowances (RDA) was considered when the intake of a vitamin was below the recommendation. Analyses were performed with logistic regression and adjusted for main confounders.

Results

during a 3.5-year follow-up, 89 (5.4%) participants developed frailty. The odds ratios (95% confidence interval) of frailty for those in the lowest versus the highest tertile of vitamin intake were 2.80 (1.38-5.67), P-trend: 0.004, for vitamin B6; 1.65 (0.93-2.95), P-trend: 0.007, for vitamin C; 1.93 (0.99-3.83), P-trend: 0.06, for vitamin E and 2.34 (1.21-4.52), P-trend: 0.01, for folates. Nonadherence to the RDAs of vitamins was related to frailty for thiamine odds ratio (OR): 2.09 (1.03-4.23); niacin OR: 2.80 (1.46-5.38) and vitamin B6; 2.23 (1.30-3.83). When considering tertiles of RDAs for the 10 vitamins those who met <5 RDAs had a higher risk of frailty, OR: 2.84 (1.34-6.03); P-trend: <0.001, compared to those who met >7.

Conclusion

a lower intake of vitamins B6, C, E and folates was associated with a higher risk of frailty. Not meeting RDAs for vitamins was also strongly associated.

Selected B vitamins and their possible link to the aetiology of age-related sarcopenia: relevance of UK dietary recommendations

The possible roles of selected B vitamins in the development and progression of sarcopenia are reviewed. Age-related declines in muscle mass and function are associated with huge and increasing costs to healthcare providers. Falls and loss of mobility and independence due to declining muscle mass/function are associated with poor clinical outcomes and their prevention and management are attractive research targets. Nutritional status appears a key modifiable and affordable intervention. There is emerging evidence of sarcopenia being the result not only of diminished anabolic activity but also of declining neurological integrity in older age, which is emerging as an important aspect of the development of age-related decline in muscle mass/function. In this connection, several B vitamins can be viewed as not only cofactors in muscle synthetic processes, but also as neurotrophic agents with involvements in both bioenergetic and trophic pathways. The B vitamins thus selected are examined with respect to their relevance to multiple aspects of neuromuscular function and evidence is considered that requirements, intakes or absorption may be altered in the elderly. In addition, the evidence base for recommended intakes (UK recommended daily allowance) is examined with particular reference to original datasets and their relevance to older individuals. It is possible that inconsistencies in the literature with respect to the nutritional management of sarcopenia may, in part at least, be the result of compromised micronutrient status in some study participants. It is suggested that in order, for example, for intervention with amino acids to be successful, underlying micronutrient deficiencies must first be addressed/eliminated.

Muscle Mass Index and Animal Source of Dietary Protein Are Positively Associated with Insulin Resistance in Participants of the NuAge Study

OBJECTIVES

Contribute evidence towards the complex interrelationships of body composition, insulin sensitivity and protein intake independently from adiposity in an older population.

DESIGN

This is a cross-sectional analysis of an existing dataset in which a literature-supported model linking together the variables of interest is tested using path analysis.

SETTING

The loss of muscle mass has been implicated in the development of insulin resistance. We propose to test associations of muscle mass with insulin sensitivity and their respective associations with animal and vegetable sources of protein intake, independently from adiposity.

PARTICIPANTS

Non-diabetic participants aged 68-82 years from the NuAge study with all available measures (n=441) were included.

MEASUREMENTS

A model considering age, sex, chronic diseases, physical activity; smoking and sources of protein intake influencing body composition components and insulin sensitivity was created and tested with Path Analysis for their independent associations. Muscle mass index (MMI; kg/height in m2) and % body fat were derived from DXA and BIA. Insulin resistance was estimated by the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) score and physical activity by the Physical Activity Scale for the Elderly (PASE) questionnaire. Protein intakes were obtained from three non-consecutive 24h-diet recalls.

RESULTS

In the final model, direct positive associations were observed between HOMA-IR score and MMI (ß=0.42; 95%CI: 0.24; 0.6) and % body fat (ß=0.094; 95%CI: 0.07; 0.11). There were no direct associations between animal protein intake and MMI or with HOMA-IR. There was a significant direct negative association between plant protein intake and MMI (ß= -0.068; 95%CI: -0.13; -0.003) and significant indirect associations mediated through MMI and % body fat between HOMA-IR and animal protein intake (ß=0.0321; 95%CI: 0.01; 0.05), as well as plant protein intake (ß= -0.07; 95%CI: -0.1; 0.0).

CONCLUSIONS

Our final model indicated that MMI and HOMA score were significantly positively associated. Protein intake sources were related to HOMA-IR score differently through MMI and % body fat, respectively.

Understanding the gastrointestinal tract of the elderly to develop dietary solutions that prevent malnutrition

Although the prevalence of malnutrition in the old age is increasing worldwide a synthetic understanding of the impact of aging on the intake, digestion, and absorption of nutrients is still lacking. This review article aims at filling the gap in knowledge between the functional decline of the aging gastrointestinal tract (GIT) and the consequences of malnutrition on the health status of elderly. Changes in the aging GIT include the mechanical disintegration of food, gastrointestinal motor function, food transit, chemical food digestion, and functionality of the intestinal wall. These alterations progressively decrease the ability of the GIT to provide the aging organism with adequate levels of nutrients, what contributes to the development of malnutrition. Malnutrition, in turn, increases the risks for the development of a range of pathologies associated with most organ systems, in particular the nervous-, muscoskeletal-, cardiovascular-, immune-, and skin systems. In addition to psychological, economics, and societal factors, dietary solutions preventing malnutrition should thus propose dietary guidelines and food products that integrate knowledge on the functionality of the aging GIT and the nutritional status of the elderly. Achieving this goal will request the identification, validation, and correlative analysis of biomarkers of food intake, nutrient bioavailability, and malnutrition.

Nutritional status and eating habits of the institutionalised elderly in Turkey: a follow-up study

BACKGROUND

As the elderly population increases in Turkey, so do the associated health and nutritional problems. The main purpose of the present study was to determine the nutritional status of elderly individuals who live in institutions.

METHODS

A total of 102 elderly volunteers was recruited from seven residential homes of the Ministry of Family and Social Policies in Ankara. In the consecutive years of 2007, 2008 and 2009, dietary intake was assessed using a 24-h food recall. Nutritional status was screened using a questionnaire from the Mini-Nutritional Assessment, basic characteristics were determined and anthropometric measurements were assessed.

RESULTS

The percentage of elderly participants who were malnourished or at risk for malnutrition increased by the completion of the follow-up (P < 0.05). It was found that energy, total protein, animal proteins, carbohydrates, niacin, vitamin C, vitamin E and zinc intake of men decreased significantly over the years studied (P < 0.05). A significant decrease occurred among women in animal protein, vitamin B1 , niacin and the percentage of energy from proteins (P < 0.05); however, an increase in energy from fat (P < 0.05) was determined. Within the years studied, the percentage of nutrients meeting the Turkish recommended daily allowances decreased from 2007 to 2009 both in men and women. During the years 2007 to 2009, the percentage of waist circumferences >102 cm for men was 46.4%, 45.6% and 48.1%, respectively, and the percentage of waist circumferences for women >88 cm was 75.6%, 75.6% and 81.8%, respectively.

CONCLUSIONS

During the follow-up, significant nutritional changes were determined. To prevent malnutrition, periodical screening of nutritional status should be a priority and a standard policy for elderly people, especially for those institutionalised.

Micronutrient intakes and potential inadequacies of community-dwelling older adults: a systematic review

Micronutrient deficiencies and low dietary intakes among community-dwelling older adults are associated with functional decline, frailty and difficulties with independent living. As such, studies that seek to understand the types and magnitude of potential dietary inadequacies might be beneficial for guiding future interventions. We carried out a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Observational cohort and longitudinal studies presenting the habitual dietary intakes of older adults (≥65 years) were included. Sex-specific mean (and standard deviation) habitual micronutrient intakes were extracted from each article to calculate the percentage of older people who were at risk for inadequate micronutrient intakes using the estimated average requirement (EAR) cut-point method. The percentage at risk for inadequate micronutrient intakes from habitual dietary intakes was calculated for twenty micronutrients. A total of thirty-seven articles were included in the pooled systematic analysis. Of the twenty nutrients analysed, six were considered a possible public health concern: vitamin D, thiamin, riboflavin, Ca, Mg and Se. The extent to which these apparent inadequacies are relevant depends on dynamic factors, including absorption and utilisation, vitamin and mineral supplement use, dietary assessment methods and the selection of the reference value. In light of these considerations, the present review provides insight into the type and magnitude of vitamin and mineral inadequacies.

Caregivers' male gender is associated with poor nutrient intake in AD families (NuAD-trial)

OBJECTIVE

Alzheimer patients (AD) are known to be at risk for malnutrition and their older spouses may also have nutritional problems. The aim of our study was to clarify the association of caregivers' sex on the nutrient intake of AD couples.

SETTING

Our study uses the baseline data of a randomized nutritional trial exploring the effectiveness of nutrition intervention among home-dwelling AD patients.

PARTICIPANTS

The central AD register in Finland was used to recruit AD patients living with a spousal caregiver, 99 couples participated in our study.

MEASUREMENTS

Nutritional status was assessed using the Mini-Nutritional Assessment (MNA). Nutrient intakes for both AD patients and their spouses were calculated from 3-day food diaries.

RESULTS

The mean age of caregivers and AD spouses was 75.2 (SD 7.0) and 77.4 years (SD 5.6), respectively. According to the MNA, 40% of male and 52% of female AD spouses were at risk for malnutrition. Among male caregivers, the mean energy and protein intakes were 1605 kcal (SD 458) and 0.93 g/body kg (SD 0.30), whereas the respective figures for their female AD spouses were 1313 kcal (SD 340) and 0.86 g/body kg (SD 0.32), respectively. Among female caregivers, the mean energy and protein intakes were 1536 kcal (SD 402) and 1.00 g/body kg (SD 0.30), whereas the respective figures for their male AD spouses were 1897 kcal (SD 416) and 1.04 g/body kg (SD 0.30). The interaction between male caregiver sex and lower energy (p<0.001) and lower protein intake (p=0.0048) (adjusted for age and MMSE) was significant. Similar differences between caregiver sexes were observed with the intake of various nutrients.

CONCLUSIONS

A gender difference exists in the ability to cope with caregiver responsibilities related to nutrition. A need exists for tailored nutritional guidance among older individuals and especially among male caregivers.

Micronutrient Needs of the Elderly

Older adults are becoming a significant percentage of the world's population. A multitude of factors, from the normal aging process to the progression of chronic disease, influence the nutrition needs of this very diverse group of people. Appropriate micronutrient intake is of particular importance but is often suboptimal. Here we review the available data regarding micronutrient needs and the consequences of deficiencies in the ever growing aged population.

Prevalence of vitamin D inadequacy in European women aged over 80 years

Inadequate vitamin D status is associated with secondary hyperparathyroidism and increased bone turnover and bone loss, which in turn increases fracture risk. The objective of this study is to assess the prevalence of inadequate vitamin D status in European women aged over 80 years. Assessments of serum 25-hydroxyvitamin D levels (25(OH)D) were performed on 8532 European women with osteoporosis or osteopenia of which 1984 were aged over 80 years. European countries included in the study were: France, Belgium, Denmark, Italy, Poland, Hungary, United Kingdom, Spain and Germany. Two cut-offs of 25(OH)D inadequacy were fixed: <75 nmol/L (30 ng/ml) and <50 nmol/L (20 ng/ml). Mean (SD) age of the patients was 83.4 (2.9) years, body mass index was 25.0 (4.0) kg/m(2) and level of 25(OH)D was 53.3 (26.7) nmol/L (21.4 [10.7] ng/ml). There was a highly significant difference of 25(OH)D level across European countries (p<0.0001). In these women aged over 80 years, the prevalence of 25(OH)D inadequacy was 80.9% and 44.5% when considering cut-offs of 75 and 50 nmol/L, respectively. In the 397 (20.0%) patients taking supplemental vitamin D with or without supplemental calcium, the mean serum 25(OH)D level was significantly higher than in the other patients (65.2 (29.2) nmol/L vs. 50.3 (25.2) nmol/L; P<0.001). This study indicates a high prevalence of vitamin D (25(OH)D) inadequacy in old European women. The prevalence could be even higher in some particular countries.

Vitamin C deficiency in an anticoagulated patient

A 64-year-old woman presented with a hemorrhagic perifollicular rash on her legs while taking warfarin. After biopsy, vitamin C deficiency was suggested as the diagnosis, which ascorbic acid assays later confirmed. Clinical resolution of the rash followed supplementation with vitamin C. Patients on a vitamin K limited diet may also be limiting their intake of vitamin C. Physicians should be aware of this possible correlation, and consider checking vitamin C levels in patients with a perifollicular hemorrhagic rash or other signs of vitamin C deficiency while on warfarin.

Alzheimer's Disease: APP, Gamma Secretase, APOE, CLU, CR1, PICALM, ABCA7, BIN1, CD2AP, CD33, EPHA1, and MS4A2, and Their Relationships with Herpes Simplex, C. Pneumoniae, Other Suspect Pathogens, and the Immune System

Alzheimer's disease susceptibility genes, APP and gamma-secretase, are involved in the herpes simplex life cycle, and that of other suspect pathogens (C. pneumoniae, H. pylori, C. neoformans, B. burgdorferri, P. gingivalis) or immune defence. Such pathogens promote beta-amyloid deposition and tau phosphorylation and may thus be causative agents, whose effects are conditioned by genes. The antimicrobial effects of beta-amyloid, the localisation of APP/gamma-secretase in immunocompetent dendritic cells, and gamma secretase cleavage of numerous pathogen receptors suggest that this network is concerned with pathogen disposal, effects which may be abrogated by the presence of beta-amyloid autoantibodies in the elderly. These autoantibodies, as well as those to nerve growth factor and tau, also observed in Alzheimer's disease, may well be antibodies to pathogens, due to homology between human autoantigens and pathogen proteins. NGF or tau antibodies promote beta-amyloid deposition, neurofibrillary tangles, or cholinergic neuronal loss, and, with other autoantibodies, such as anti-ATPase, are potential agents of destruction, whose formation is dictated by sequence homology between pathogen and human proteins, and thus by pathogen strain and human genes. Pathogen elimination in the ageing population and removal of culpable autoantibodies might reduce the incidence and offer hope for a cure in this affliction.

Nutrition and dementia: clinical considerations for identification and intervention

SUMMARY Nutrition is linked in several ways to the diseases that cause dementia. The focus of this article is on nutrient-specific interventions, a healthy diet and management of bodyweight to delay dementia progression in individuals with mild-cognitive impairment or dementia, specifically living in the community. Epidemiological evidence suggests that a healthy plant-based diet is prudent. However, research is lacking on specific nutrient supplementation and pharmacological doses are unwarranted. Weight loss is common and potentially leads to further cognitive loss and needs to be avoided in patients presenting for diagnosis or being followed for dementia care. Nutrition screening and assessment as a means of identifying potential nutrition problems in an outpatient clinical environment are reviewed as well as interventions.

The Fox and the Rabbits-Environmental Variables and Population Genetics (1) Replication Problems in Association Studies and the Untapped Power of GWAS (2) Vitamin A Deficiency, Herpes Simplex Reactivation and Other Causes of Alzheimer's Disease

Classical population genetics shows that varying permutations of genes and risk factors permit or disallow the effects of causative agents, depending on circumstance. For example, genes and environment determine whether a fox kills black or white rabbits on snow or black ash covered islands. Risk promoting effects are different on each island, but obscured by meta-analysis or GWAS data from both islands, unless partitioned by different contributory factors. In Alzheimer's disease, the foxes appear to be herpes, borrelia or chlamydial infection, hypercholesterolemia, hyperhomocysteinaemia, diabetes, cerebral hypoperfusion, oestrogen depletion, or vitamin A deficiency, all of which promote beta-amyloid deposition in animal models—without the aid of gene variants. All relate to risk factors and subsets of susceptibility genes, which condition their effects. All are less prevalent in convents, where nuns appear less susceptible to the ravages of ageing. Antagonism of the antimicrobial properties of beta-amyloid by Abeta autoantibodies in the ageing population, likely generated by antibodies raised to beta-amyloid/pathogen protein homologues, may play a role in this scenario. These agents are treatable by diet and drugs, vitamin supplementation, pathogen detection and elimination, and autoantibody removal, although again, the beneficial effects of individual treatments may be tempered by genes and environment.