Midlife coffee and tea drinking and the risk of late-life dementia: a population-based CAIDE study.
Caffeine stimulates central nervous system on a short term. However, the long-term impact of caffeine on cognition remains unclear. We aimed to study the association between coffee and/or tea consumption at midlife and dementia/Alzheimer’s disease (AD) risk in late-life. Participants of the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study were randomly selected from the survivors of a population-based cohorts previously surveyed within the North Karelia Project and the FINMONICA study in 1972, 1977, 1982 or 1987 (midlife visit). After an average follow-up of 21 years, 1,409 individuals (71%) aged 65 to 79 completed the re-examination in 1998. A total of 61 cases were identified as demented (48 with AD). Coffee drinkers at midlife had lower risk of dementia and AD later in life compared with those drinking no or only little coffee adjusted for demographic, lifestyle and vascular factors, apolipoprotein E epsilon4 allele and depressive symptoms. The lowest risk (65% decreased) was found in people who drank 3-5 cups per day. Tea drinking was relatively uncommon and was not associated with dementia/AD. Coffee drinking at midlife is associated with a decreased risk of dementia/AD later in life. This finding might open possibilities for prevention of dementia/AD.
J Alzheimers Dis. 2009;16(1):85-91
Coenzyme Q10 protects against amyloid beta-induced neuronal cell death by inhibiting oxidative stress and activating the P13K pathway.
Oxidative stress plays critical roles in the pathogenic mechanisms of several neurodegenerative disorders including Alzheimer’s disease (AD), thus much research effort has focused on antioxidants as potential treatment agents for AD. Coenzyme Q10 (CoQ10) is known to have powerful antioxidant effects. We investigated the neuroprotective effects of CoQ10 against Amyloid beta(25-35) (Aβ(25-35))-induced neurotoxicity in rat cortical neurons. To evaluate the neuroprotective effects of CoQ10 on Aβ(25-35)-injured neurons, primary cultured cortical neurons were treated with several concentrations of CoQ10 and/or Aβ(25-35) for 48h. CoQ10 protected neuronal cells against Aβ(25-35)-induced neurotoxicity in a concentration-dependent manner. These neuroprotective effects of CoQ10 were blocked by LY294002 (10μM), a phosphatidylinositol 3-kinase (PI3K) inhibitor. Aβ(25-35) concentration-dependent increased free radical levels in rat cortical neurons, while combined treatment with CoQ10 reduced these free radical levels in a dose-dependent manner. Meanwhile, CoQ10 treatment of Aβ(25-35)-injured primary cultured cortical neurons increased the expression levels of p85aPI3K, phosphorylated Akt, phosphorylated glycogen synthase kinase-3β, and heat shock transcription factor, which are proteins related to neuronal cell survival, and decreased the levels of cytosolic cytochrome c and cleaved caspase-3, which are associated with neuronal cell death. Together, these results suggest that the neuroprotective effects of CoQ10 on Aβ(25-35) neurotoxicity are mediated by inhibition of oxidative stress together with activation of the PI3-K/Akt pathway.
Neurotoxicology. 2012 Jan;33(1):85-90
Efficacy and tolerability of a once daily formulation of Ginkgo biloba extract EGb 761® in Alzheimer’s disease and vascular dementia: results from a randomised controlled trial.
INTRODUCTION: A 24-week randomised controlled trial was conducted to assess the efficacy of a 240 mg once-daily preparation of Ginkgo biloba extract EGb 761® in 404 outpatients ≥ 50 years diagnosed with mild to moderate dementia (SKT 9-23), Alzheimer’s disease (AD) or vascular dementia (VaD), with neuropsychiatric features (NPI total score ≥ 5). METHODS: Separate analyses were performed for diagnostic subgroups (probable or possible AD; VaD). RESULTS: 333 patients were diagnosed with AD and 71 with VaD. EGb 761® treatment was superior to placebo with respect to the SKT total score (drug-placebo differences: 1.7 for AD, p<0.001, and 1.4 for VaD, p<0.05) and the NPI total score (drug-placebo differences: 3.1 for AD, p<0.001 and 3.2 for VaD, p<0.05). Significant drug-placebo differences were found for most secondary outcome variables with no major differences between AD and VaD subgroups. Rates of adverse events in EGb 761® and placebo groups were essentially similar. CONCLUSION: EGb 761® improved cognitive functioning, neuropsychiatric symptoms and functional abilities in both types of dementia.
Pharmacopsychiatry. 2012 Mar;45(2):41-6
Panax ginseng enhances cognitive performance in Alzheimer disease.
Recent experimental evidences suggest protective and trophic effects of ginseng in the memory function of Alzheimer disease (AD). Thus, we investigated the clinical efficacy of Panax ginseng in the cognitive performance of AD patients in an open-label study. Consecutive AD patients were randomly assigned to the ginseng (n=58) or the control group (n=39), and the ginseng group was treated with Panax ginseng powder (4.5 g/d) for 12 weeks. Cognitive performances were monitored using the mini-mental state examination (MMSE) and Alzheimer disease assessment scale (ADAS) during 12 weeks of the ginseng treatment and at 12 weeks after the ginseng discontinuation. MMSE and ADAS scales showed no baseline difference between the groups. After ginseng treatment, the cognitive subscale of ADAS and the MMSE score began to show improvements and continued up to 12 weeks (P=0.029 and P=0.009 vs. baseline, respectively). After discontinuing ginseng, the improved ADAS and MMSE scores declined to the levels of the control group. These results suggest that Panax ginseng is clinically effective in the cognitive performance of AD patients.
Alzheimer Dis Assoc Disord. 2008 Jul-Sep;22 (3):222-6
Huperzine A activates Wnt/β-catenin signaling and enhances the nonamyloidogenic pathway in an Alzheimer transgenic mouse model.
Huperzine A (HupA) is a reversible and selective inhibitor of acetylcholinesterase (AChE), and it has multiple targets when used for Alzheimer’s disease (AD) therapy. In this study, we searched for new mechanisms by which HupA could activate Wnt signaling and reduce amyloidosis in AD brain. A nasal gel containing HupA was prepared. No obvious toxicity of intranasal administration of HupA was found in mice. HupA was administered intranasally to β-amyloid (Aβ) precursor protein and presenilin-1 double-transgenic mice for 4 months. We observed an increase in ADAM10 and a decrease in BACE1 and APP695 protein levels and, subsequently, a reduction in Aβ levels and Aβ burden were present in HupA-treated mouse brain, suggesting that HupA enhances the nonamyloidogenic APP cleavage pathway. Importantly, our results further showed that HupA inhibited GSK3α/β activity, and enhanced the β-catenin level in the transgenic mouse brain and in SH-SY5Y cells overexpressing Swedish mutation APP, suggesting that the neuroprotective effect of HupA is not related simply to its AChE inhibition and antioxidation, but also involves other mechanisms, including targeting of the Wnt/β-catenin signaling pathway in AD brain.
Neuropsychopharmacology. 2011 Apr;36(5):1073-89
The combination of exercise training and alpha-lipoic acid treatment has therapeutic effects on the pathogenic phenotypes of Alzheimer’s disease in NSE/APPsw-transgenic mice.
Exercise training was suggested as a practical therapeutic strategy for human subjects suffering from Alzheimer’s disease (AD) in our previous study. Therefore, the purpose of this study was to investigate the effects of combining exercise training with the administration of antioxidants on the pathological phenotype of AD. To accomplish this, non-transgenic mice (Non-Tg) and NSE/APPsw Tg mice were treated with alpha-lipoic acid and treadmill exercised for 16 weeks, after which their brains were evaluated to determine whether any changes in the pathological phenotype-related factors occurred. The results indicated that (i) the combination-applied (COMA) Tg group with exercise training (ET) and alpha-lipoic acid administration (LA) showed ameliorated spatial learning and memory compared to the sedentary (SED)-Tg and single-treatment groups; (ii) there were no differences in the level of Abeta-42 peptides across groups; (iii) the level of glucose transporter-1 and brain-derived neurotrophic factor proteins were highly increased in the COMA group, (iv) ET and LA did not induce a synergistic effect on the expression of heat shock protein-70 and apoptotic proteins including Bax and caspase-3; (v) the levels of SOD-1 and CAT suppressing oxidative stress were extensively higher in the COMA than in the single-treated groups and (vi) there were no significant differences across groups regarding these serum characteristics, although these levels were lower than the SED-Tg group. Taken together, these results suggest that the combination with ET and LA may contribute to protect the neuron injury induced by Abeta peptides and may be considered an effective therapeutic strategy for human subjects suffering from AD.
Int J Mol Med. 2010 Mar;25(3):337-46
Pleiotropic protective effects of phytochemicals in Alzheimer’s disease.
Alzheimer’s disease (AD) is a severe chronic neurodegenerative disorder of the brain characterised by progressive impairment in memory and cognition. In the past years an intense research has aimed at dissecting the molecular events of AD. However, there is not an exhaustive knowledge about AD pathogenesis and a limited number of therapeutic options are available to treat this neurodegenerative disease. Consequently, considering the heterogeneity of AD, therapeutic agents acting on multiple levels of the pathology are needed. Recent findings suggest that phytochemicals compounds with neuroprotective features may be an important resources in the discovery of drug candidates against AD. In this paper we will describe some polyphenols and we will discuss their potential role as neuroprotective agents. Specifically, curcumin, catechins, and resveratrol beyond their antioxidant activity are also involved in antiamyloidogenic and anti-inflammatory mechanisms. We will focus on specific molecular targets of these selected phytochemical compounds highlighting the correlations between their neuroprotective functions and their potential therapeutic value in AD.
Oxid Med Cell Longev. 2012;2012:386527
Vitamin D-mentia: randomized clinical trials should be the next step.
Hypovitaminosis D is highly prevalent in the elderly. Its possible role in the pathogenesis of Alzheimer’s disease (AD) is particularly important, as AD remains a public health concern with no current efficient treatment. Vitamin D administration could be a multitarget stabilizing treatment for AD since vitamin D simultaneously targets several factors leading to neurodegeneration through immunoregulatory, antioxidant and anti-ischemic actions, as well as the regulation of neurotrophic factors, acetylcholine neurotransmitter and clearance of amyloid beta peptide, and the avoidance of hyperparathyroidism. By preventing neuronal loss, the question is whether correcting hypovitaminosis D among older adults could also prevent AD-related cognitive decline. The cross-sectional associations between the vitamin D intakes--whether from diet, sun exposure or drug supplements--and cognition strengthened this hypothesis, but prevented the finding of a cause and effect link. Pre-post studies showed an improvement of cognition concomitant with the increase in 25-hydroxyvitamin D concentrations. One randomized trial found that supraphysiological doses of vitamin D were not better than physiological doses at improving cognition in AD. At this stage, only clinical trials testing vitamin D supplements versus placebo can further determine the impact of vitamin D administration on cognition and AD with higher levels of evidence.
Formulation of a medical food cocktail for Alzheimer’s disease: beneficial effects on cognition and neuropathology in a mouse model of the disease.
BACKGROUND: Dietary supplements have been extensively studied for their beneficial effects on cognition and AD neuropathology. The current study examines the effect of a medical food cocktail consisting of the dietary supplements curcumin, piperine, epigallocatechin gallate, α-lipoic acid, N-acetylcysteine, B vitamins, vitamin C, and folate on cognitive functioning and the AD hallmark features and amyloid-beta (Aβ) in the Tg2576 mouse model of the disease. PRINCIPAL FINDINGS: The study found that administering the medical food cocktail for 6 months improved cortical- and hippocampal- dependent learning in the transgenic mice, rendering their performance indistinguishable from non-transgenic controls. Coinciding with this improvement in learning and memory, we found that treatment resulted in decreased soluble Aβ, including Aβ oligomers, previously found to be linked to cognitive functioning. CONCLUSION: In conclusion, the current study demonstrates that combination diet consisting of natural dietary supplements improves cognitive functioning while decreasing AD neuropathology and may thus represent a safe, natural treatment for AD.
PLoS One. 2010 Nov 17;5(11):e14015