Vascular effects of the Mediterranean diet part I: anti-hypertensive and anti-thrombotic effects.

This review summarizes available evidence on the beneficial effects of inorganic nitrates and the monounsaturated fatty acid (MUFA) oleic acid, largely contained in Mediterranean diet, on blood pressure and coagulation activity. Inorganic nitrate. Normal vascular function requires NO production from the 1-arginine-NO synthase (NOS) pathway. This process is defective in conditions of local hypoxia, and here nitrite can substitute for 1-arginine-NOS derived NO. In this context, NO generation from the nitrate-nitrite-NO pathway mostly derived from green leafy vegetables appears to be an alternative source for NOS-dependent NO production, ensuring NO bioavailability also in situations when the endogenous 1-arginine/NO synthase pathway is dysfunctional or physiologically reduced in local hypoxic conditions. Olive oil and oleic acid. In addition to effects on lipoprotein metabolism and oxidation, the beneficial effects of oleic acid occur also on coagulation activity, namely on coagulation factor VII (FVII). Normally, a substantial increase of FVII coagulant activity (FVIIc) occurs within 2-3h after a fatty meal and persists for several hours thereafter. When a background diet high in MUFA is consumed, a lower post-prandial increase of FVIIc takes place.

Towards disease-modifying treatment of Alzheimer's disease: drugs targeting beta-amyloid.

Pathological, genetic, biochemical and pharmacological studies support the hypothesis that brain accumulation of oligomeric species of beta-amyloid (Abeta) peptides may cause Alzheimer's disease (AD). Drugs currently used for the treatment of AD produce limited clinical benefits and do not treat the underlying causes of the disease. In the last 10 years, new therapeutic approaches targeting Abeta have been discovered and developed with the hope of modifying the natural history of the disease. Several active and passive immunotherapy approaches are under investigation in clinical trials with the aim of accelerating Abeta clearance from the brain of the AD patients. The most advanced of these immunological approaches is bapineuzumab, composed of humanized anti-Abeta monoclonal antibodies, that is being tested in two large late-stage trials. Compounds that interfere with proteases regulating Abeta formation from amyloid precursor protein (APP) are also actively pursued. Unfortunately, the most biologically attractive of these proteases, beta-secretase, that regulates the first step of the amyloidogenic APP metabolism, was found to be particularly problematic to block and only one compound (CTS21166) has reached clinical testing so far. Conversely, several inhibitors of gamma-secretase, the protease that regulates the last metabolic step generating Abeta, have been identified, the most advanced being LY-450139 (semagacestat), presently in Phase III clinical development. Compounds that stimulate alpha-secretase, the enzyme responsible for the non-amyloidogenic metabolism of APP, are also being developed one of them, EHT-0202, has recently started a Phase II study. Furthermore, brain penetrant inhibitors of Abeta aggregation have been identified and one of such compounds, PBT-2, has produced encouraging neuropsychological results in a recently completed Phase II study. With all these anti-Abeta approaches in clinical testing, we will know in few years if the Abeta hypothesis of AD is correct.

Vascular risk factors, alcohol intake, and cognitive decline.

Since the therapeutic options currently available have demonstrated limited efficacy, the search for preventive strategies for cognitive decline and dementia is mandatory. A possible role of vascular and lifestyle-related factors was recently proposed for age-related changes of cognitive function, predementia syndromes, and cognitive decline of degenerative (Alzheimer's disease, AD) or vascular origin. At present, cumulative evidence suggested that vascular risk factors may be important in the development of mild cognitive impairment (MCI), dementia, and AD. Among vascular-related factors, metabolic syndrome has been associated with the risk of cognitive decline and overall dementia. Moderate alcohol drinking has been proposed as a protective factor against MCI and dementia in several longitudinal studies, but contrasting findings also exist. However, in most cases, these were only observational studies, and results are awaited from large multicenter randomized clinical trials in older persons. At present, vascular risk factor management, lifestyle changes, and drugs could be employed together to delay the onset of dementia syndromes.

Dietary fatty acids, age-related cognitive decline, and mild cognitive impairment.

Currently available epidemiological evidence suggested that an increase of saturated fatty acids (SFA) could have negative effects on cognitive functions, while increased polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) may be protective against cognitive decline. In a Southern Italian elderly population from the Italian Longitudinal Study on Aging (ILSA), a clear reduction of risk of age-related cognitive decline (ARCD) has been found with elevated intake of PUFA and MUFA. Furthermore, in the ILSA, while dietary fatty acids intakes were not associated with incident mild cognitive impairment (MCI), high PUFA intake appeared to have borderline non-significant trend for a protective effect against the development of MCI. These epidemiological findings on predementia syndromes, i.e. MCI or ARCD, together with a recent randomised controlled trial on a possible effect on cognitive and depressive symptoms of omega-3 PUFA supplementation in patients with very mild AD, suggested a possible role of fatty acids intake in maintaining adequate cognitive functioning and possibly in preventing or delaying the onset of dementia.

Interleukin 6 variable number of tandem repeats (VNTR) gene polymorphism in centenarians.

Recent population-based studies identified the magnitude of interleukin 6 (IL6) serum levels as a marker for functional disability, and a predictor of disability and mortality among the elderly. We investigated whether there was evidence in Southern Italy of an association between the IL6 gene variable number of tandem repeats (VNTR) polymorphism and extreme longevity, and tested for the possible interaction of apolipoprotein E (APOE) alleles with the IL6 VNTR alleles. Four alleles coding for variants of four different lengths have been identified: allele A [760 base pairs (bp)], allele B (680 bp), allele C (640 bp), and allele D (610 bp). IL6 VNTR and APOE allele and genotype frequencies were studied in a total of 61 centenarians and 94 middle-aged subjects from Southern Italy. The IL6 VNTR allele B was overrepresented in the younger control group compared with centenarians (odds ratio: 0.56, 95% confidence interval: 0.35-0.88, Bonferroni p-value < 0.05). No interactions between IL6 VNTR alleles and APOE alleles on the odds ratios to reach extreme longevity were evaluated for the smallest number of subjects in centenarians and younger controls. Our findings suggested that the presence of the IL6 VNTR allele B could be detrimental for reaching extreme longevity.

Alcohol consumption, mild cognitive impairment, and progression to dementia.

OBJECTIVE: To estimate the impact of alcohol consumption on the incidence of mild cognitive impairment and its progression to dementia. METHODS: We evaluated the incidence of mild cognitive impairment in 1,445 non-cognitively impaired individuals and its progression to dementia in 121 patients with mild cognitive impairment, aged 65 to 84 years, participating in the Italian Longitudinal Study on Aging, with a 3.5-year follow-up. The level of alcohol consumption was ascertained in the year before the survey. Dementia and mild cognitive impairment were classified using current clinical criteria. RESULTS: Patients with mild cognitive impairment who were moderate drinkers, i.e., those who consumed less than 1 drink/day (approximately 15 g of alcohol), had a lower rate of progression to dementia than abstainers (hazard ratio [HR] 0.15; 95% CI 0.03 to 0.78). Furthermore, moderate drinkers with mild cognitive impairment who consumed less than 1 drink/day of wine showed a significantly lower rate of progression to dementia than abstainers (HR 0.15; 95% CI 0.03 to 0.77). Finally, there was no significant association between higher levels of drinking (> or =1 drink/day) and rate of progression to dementia in patients with mild cognitive impairment vs abstainers. No significant associations were found between any levels of drinking and the incidence of mild cognitive impairment in non-cognitively impaired individuals vs abstainers. CONCLUSIONS: In patients with mild cognitive impairment, up to 1 drink/day of alcohol or wine may decrease the rate of progression to dementia.

Predictors of high level of burden and distress in caregivers of demented patients: results of an Italian multicenter study.

BACKGROUND: Considerable suffering is experienced by carers of patients with dementia. Most existing studies do not consider the coexistence of subjective and objective aspects that cause, interacting to each other, this suffering. OBJECTIVES: In this study we: (1) define the high-risk group of caregivers on the bases of the scores obtained on the four scales evaluating burden, distress, depression and anxiety (BDDA) taken into account simultaneously and (2) evaluate risk factors related to the high level of BDDA. SUBJECTS AND METHODS: 419 elderly outpatients with dementia and their caregivers were enrolled. Patients were evaluated for their cognitive, neuropsychological and functional impairment and for comorbidity. Caregivers were evaluated with four scales for the assessment of burden, distress related to neuropsychological disturbances, depression and anxiety. Cluster analysis was used to identify the group with the High level of BDDA (HBDDA). RESULTS: By multiple logistic analysis, disability, specific behavioural disturbances of the patients as well as caregiver's age, type of relationship and living in the south of Italy were observed to be a major risk factor for HBDDA. CONCLUSION: The targeted use of scales specifically assessing BDDA of the caregiver and the identification of particular patient and caregiver characteristics are able to allow a precise and early definition of caregivers at high risk of burden and distress. This might be helpful in planning the correct social/clinical/rehabilitative approach.

Vascular risk factors, incidence of MCI, and rates of progression to dementia.

OBJECTIVE: To estimate prevalence, incidence, and rate of progression of mild cognitive impairment (MCI) to dementia and correlated vascular risk factors with incident MCI and its progression to dementia. METHODS: The authors evaluated 2,963 individuals from the population-based sample of 5,632 subjects 65 to 84 years old, at the first (1992 to 1993) and second survey (1995 to 1996) of the Italian Longitudinal Study on Aging (ILSA), with a 3.5-year follow-up. Dementia, Alzheimer disease (AD), vascular dementia (VaD), other types of dementia, and MCI were classified using current clinical criteria. RESULTS: Among the 2,963 participants, 139 MCI patients were diagnosed at the first ILSA survey. During the 3.5-year follow-up, 113 new events of MCI were diagnosed with an estimated incidence rate of 21.5 per 1,000 person-years. We found a progression rate to dementia (all causes) of 3.8/100 person-years. Specific progression rates for AD, VaD, and other types of dementia were 2.3, 1.3, and 0.3/100 person-years. Furthermore, age was a risk factor for incident MCI (RR: 5.93, 95% CI: 3.17 to 11.10), while education was protective (RR: 0.06, 95% CI: 0.03 to 0.10), and serum total cholesterol evidenced a borderline nonsignificant trend for a protective effect. There was a nonsignificant trend for stroke as a risk factor of progression of MCI to dementia. CONCLUSIONS: In this population, among those who progressed to dementia, 60% progressed to AD and 33% to VaD. Vascular risk factors influence incident mild cognitive impairment and the rate of progression to dementia.

Mediterranean diet and cognitive decline.

OBJECTIVE: To investigate the possible role of diet in age-related cognitive decline (ARCD) and cognitive impairment of both degenerative (Alzheimer's disease, AD) and vascular (vascular dementia, VaD) origin. DESIGN: Literature review. RESULTS: In an elderly population of southern Italy with a typical Mediterranean diet, high energy intake of monounsaturated fatty acids (MUFA) appeared to be associated with a high level of protection against ARCD. In addition, dietary fat and energy in the elderly seem to be risk factors, while fish consumption and cereals are found to reduce the prevalence of AD in European and North American countries. Finally, the relative risk of dementia (AD and VaD) was lower in the subjects of a French cohort who drank three or four glasses of red wine each day compared with total abstainers. CONCLUSION: Essential components of the Mediterranean diet--MUFA, cereals and wine--seem to be protective against cognitive decline. As such, dietary antioxidants and supplements, specific macronutrients of the Mediterranean diet, oestrogens and anti-inflammatory drugs may act synergistically with other protective factors, opening up new therapeutic interventions for cognitive decline.

Vascular risk and genetics of sporadic late-onset Alzheimer's disease.

In recent years, it is becoming apparent that genes may play an important role in the development of late-onset Alzheimer's disease (LOAD), and genetic studies could unravel new clues. Based on a growing vascular hypothesis for the pathogenesis of LOAD and other dementias, there is increasing interest for environmental and genetic vascular factors. Polymorphisms in different susceptibility genes already implicated in vascular disease risk are now also being suggested as possible genetic markers for increased risk of developing LOAD; however, many of these studies have shown conflicting results. Thus far, the apolipoprotein E (APOE) gene seems to be the only vascular susceptibility factor that is agreed to play a role in the multifactorial pathogenesis of AD although emerging genetic and biological evidence is now strengthening the case for additional inclusion of angiotensin I-converting enzyme 1 (ACE1) into this category. This review will focus on the current knowledge on genetic and nongenetic vascular factors likely to be involved in LOAD, with special emphasis placed on the APOE and ACE1 genes.

The role of diet in cognitive decline.

Recent findings suggest a possible role of diet in age-related cognitive decline, and cognitive impairment of both degenerative (Alzheimer's disease, AD) or vascular origin. In particular, in an older population of Southern Italy with a typical Mediterranean diet, high monounsaturated fatty acids energy intake appeared to be associated with a high protection against cognitive decline. In addition, dietary fat and energy in older people seem to be risk factors, while fish consumption and cereals are found to reduce the prevalence of AD in the European and North American countries. Moreover, foods with large amounts of aluminium-containing additives or aluminium from drinking water may affect the risk of developing AD. Vitamin deficiencies, especially vitamin B6, B12 and folates, and antioxidant deficiencies (vitamins E and C) could also influence the memory capabilities and have an effect on cognitive decline. Dietary anti-oxidants and supplements and specific macronutrients of the diet may act synergistically with other protective factors opening new possibilities of intervention for cognitive decline.

F175S change and a novel polymorphism in presenilin-1 gene in late-onset familial Alzheimer's disease.

We analyzed at the molecular level with presenilin-1 (PS-1) and apolipoprotein E (apoE) genotyping the affected subjects and asymptomatic relatives of an Italian family with several members affected by late-onset familial Alzheimer's disease (AD). The screen for PS-1 gene mutations revealed a novel missense substitution phenylalanine 175 to serine in 1 of the affected individuals and 2 asymptomatic sons of the patient. This change was not found in other relatives of this family, as well as in 60 individuals with sporadic late-onset AD and 40 normal controls. Furthermore, a GG/TT substitution in the 3' end of intron 6 at the boundary with exon 7 was found in all relatives of the second and third generations of this family. All the affected relatives were female homo- or heterozygotes for apoE epsilon4 allele. This study provides evidence that a PS-1 gene missense change does not necessarily associate with early-onset disease, and can occur in single cases affected by late-onset disease.

Lipoprotein(a), apolipoprotein E genotype, and risk of Alzheimer's disease.

OBJECTIVES: To explore the possible role of serum lipoprotein(a) (Lp(a)), apolipoprotein E polymorphism, and total cholesterol (TC) serum concentrations in Alzheimer's disease (AD). METHODS: Lp(a) serum concentrations, apolipoprotein E genotypes, and TC serum concentrations were determined in 61 patients with a diagnosis of probable AD and in 63 healthy unrelated age matched controls. Genomic DNA was obtained and amplified by polymerase chain reaction and apolipoprotein E genotypes were defined following a previously described procedure. RESULTS: Lp(a) serum concentrations were significantly associated in a non-linear relation with an increased risk for AD, independently of apolipoprotein E genotypes and sex and dependent on age (truth association) and TC serum concentrations (spurious association). The effect of age adjusted for TC on the odds of having AD increased non-linearly with increasing Lp(a) serum concentrations, with a plateau between 70 and 355 mg/l (odds ratio 11.33). For Lp(a) serum concentrations > or = 360 mg/l, the effect of age (> or = 72 years) was associated with a reduction in odds of having AD (odds ratio 0.15). CONCLUSION: It is suggested that increased Lp(a) serum concentrations, by increasing the risk for cerebrovascular disease, may have a role in determining clinical AD.