Effect of a Vegan Diet on Alzheimer’s Disease

There is evidence indicating that a vegan diet could be beneficial in the prevention of neurodegenerative disorders, including Alzheimer’s disease (AD). The purpose of this review is to summarize the current knowledge on the positive and negative aspects of a vegan diet regarding the risk of AD. Regarding AD prevention, a vegan diet includes low levels of saturated fats and cholesterol, contributing to a healthy blood lipid profile. Furthermore, it is rich in phytonutrients, such as vitamins, antioxidants, and dietary fiber, that may help prevent cognitive decline. Moreover, a vegan diet contributes to the assumption of quercetin, a natural inhibitor of monoamine oxidase (MAO), which can contribute to maintaining mental health and reducing AD risk. Nonetheless, the data available do not allow an assessment of whether strict veganism is beneficial for AD prevention compared with vegetarianism or other diets. A vegan diet lacks specific vitamins and micronutrients and may result in nutritional deficiencies. Vegans not supplementing micronutrients are more prone to vitamin B12, vitamin D, and DHA deficiencies, which have been linked to AD. Thus, an evaluation of the net effect of a vegan diet on AD prevention and/or progression should be ascertained by taking into account all the positive and negative effects described here

Famous Landmark Identification in Amnestic Mild Cognitive Impairment and Alzheimer\u27s Disease

Background: Identification of famous landmarks (FLI), famous faces (FFI) and recognition of facial emotions (FER) is affected early in the course of Alzheimer’s disease (AD). FFI, FER and FLI may represent domain specific tasks relying on activation of distinct regions of the medial temporal lobe, which are affected successively during the course of AD. However, the data on FFI and FER in MCI are controversial and FLI domain remains almost unexplored. Objectives: To determine whether and how are these three specific domains impaired in head to head comparison of patients with amnestic MCI (aMCI) single domain (SD-aMCI) and multiple domain (MD-aMCI). We propose that FLI might be most reliable in differentiating SD-aMCI, which is considered to be an earlier stage of AD pathology spread out, from the controls. Patients and Methods: A total of 114 patients, 13 with single domain (SD–aMCI) and 30 with multiple domains (MD–aMCI), 29 with mild AD and 42 controls underwent standard neurological and neuropsychological evaluations as well as tests of FLI, FER and FFI. Results: Compared to the control group, AD subjects performed worse on FFI (p = 0.020), FER (p,0.001) and FLI (p,0.001), MD-aMCI group had significantly worse scores only on FLI (p = 0.002) and approached statistical significance on FER (0.053). SD-aMCI group performed significantly worse only on FLI (p = 0.028) compared to controls. Conclusions: Patients with SD-aMCI had an isolated impairment restricted to FLI, while patients with MD–aMCI showed impairment in FLI as well as in FER. Patients with mild dementia due to AD have more extensive impairment of higher visual perception. The results suggest that FLI testing may contribute to identification of patients at risk of AD. We hypothesize that clinical examination of all three domains might reflect the spread of the disease from transentorhinal cortex, over amygdala to fusiform gyrus

Recognition of facial emotional expression in amnestic mild cognitive impairment

We examined whether recognition of facial emotional expression would be affected in amnestic mild cognitive impairment (aMCI). A total of 50 elderly persons met the initial inclusion criteria; 10 were subsequently excluded (Geriatric Depression Score \u3e 5). 22 subjects were classified with aMCI based on published criteria (single domain aMCI [SD-aMCI], n = 10; multiple domain aMCI [MD-aMCI], n = 12); 18 subjects were cognitively normal. All underwent standard neurological and neuropsychological evaluations as well as tests of facial emotion recognition (FER) and famous faces identification (FFI). Among normal controls, FFI was negatively correlated with Mini-Mental Status Examination scores and positively correlated with executive function. Among patients with aMCI, FER was correlated with attention/speed of processing. No other correlations were significant. In a multinomial logistic regression model adjusted for age, gender, and education, a poorer score on FER, but not on FFI, was associated with greater odds of being classified as MD-aMCI (odds ratio [OR], 3.82; 95% confidence interval [CI], 1.05-13.91; p = 0.042). This association was not explained by memory or global cognitive score. There was no association between FER or FFI and SD-aMCI (OR, 1.13; 95% CI, 0.36-3.57; p = 0.836). Therefore, FER, but not FFI, may be impaired in MD-aMCI. This implies that in MD-aMCI, the tasks of FER and FFI may involve segregated neurocognitive networks. © 2013 - IOS Press and the authors. All rights reserved

Demographic characteristics of the groups.

<p>Mean values (SD); Auditory Verbal Learning Test (AVLT) trials 1–6 and AVLT Delayed Recall (AVLT 30), Rey-Osterrieth Complex Figure Copy (ROCF - C) and Recall (ROCF – R), Free and Cued Selective Reminding Test (FCSRT) total recall, Digit Span Backward (DSB), Trail Making Test (TMT) A and B, Controlled Oral Word Association (COWAT), Boston Naming Test errors (BNT err.); one-way ANOVA - between-group differences.</p>a<p>ANOVA, ^bX² test, ^cPartial eta ², ^dCramér's V, * p<.05, **<.01, ***<.001 (compared to the control group) Note: Partial eta² of 0.2 corresponds to Cohen's d of 1.0 with our sample size, Cramér's V of about 0.175 corresponds to Cohen's d of 0.356.</p

Correlations of FFI, FER and FLI with cognitive domains (EGM – correlations controlled for effect of group membership).

<p>* p<0.05, **<0.01, ***<0.001 values in bold indicate significant correlations after Holm-Bonferroni correction for multiple comparisons. The tests used for testing each cognitive domain are closely described in the methods.</p

Differences across groups in the FLI test.

<p>The total number of correctly recognized places as familiar or unfamiliar (correct rejections) in each group is depicted. * p<0.05, ** p<0.01, *** p<0.001. Note: mean, median and interquartile ranges characterise performance of each group. FLI  =  Test of famous landmarks identification, SD-aMCI  =  single domain amnestic mild cognitive impairment, MD-aMCI  =  multiple domain amnestic mild cognitive impairment, AD  =  Alzheimer's disease dementia.</p

Test of famous landmarks identification.

<p>Illustration of two famous places for the Czech population and two similar but unfamiliar places. For each place, the participant decided whether the place was familiar or not.</p

Differences across groups in the FER test.

<p>The total number of correctly recognized emotions in each group is depicted. * p<0.05, *** p<0.001. Note: mean, median and interquartile ranges characterise performance of each group. FER  =  Test of facial emotions recognition, SD-aMCI  =  single domain amnestic mild cognitive impairment, MD-aMCI  =  multiple domain amnestic mild cognitive impairment, AD  =  Alzheimer's disease dementia.</p