Cholesterol in midlife increases the risk of Alzheimer's disease during an up to 43-year follow-up

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.

Lipid levels and the risk of dementia: A dose-response meta-analysis of prospective cohort studies

OBJECTIVES

We performed a dose-response meta-analysis to estimate the association between lipid profiles with the risk of dementia and the potential differences according to the subtype of dementia based on prospective studies.

METHODS

We searched PubMed, Embase and Web of Science for relevant articles and performed a meta-analysis. We applied fixed or random-effects models to calculate pooled relative risk (RR) with their 95% confidence intervals (CI). The dose-response relationship was assessed by restricted cubic spline.

RESULTS

Twenty-five prospective studies comprising 362,443 participants and 20,121 cases were included in the final analysis. We found that increased risk of all-cause dementia could be predicted by elevated total cholesterol (TC) (RR = 1.13, 95% CI 1.04-1.22). When looking at dementia subtypes, we also observed high TC and triglycerides (TG) may increase the future risk of Alzheimer's disease (AD), with a pooled RR of 1.13 (95% CI: 1.06-1.21) and 1.10 (95% CI: 1.04-1.15) respectively. Moreover, a dose-response analysis revealed a linear association between TC or TG and the risk of AD, with a pooled RR of 1.09 (95% CI: 1.02-1.16) and 1.12 (95% CI: 1.05-1.21) for per 3-mmol/L increment in TC and TG, respectively.

CONCLUSIONS

Current evidence suggest that every 3-mmol/L increase in blood TC or TG is linearly associated with a 9% or 12% increase in RR of AD, supporting the notion that high TC and TG levels appear to play a causal role in the development of AD.

Gene-environment interactions in Alzheimer's disease: A potential path to precision medicine

Alzheimer's disease (AD) is the leading cause of dementia in the United States and afflicts >5.7 million Americans in 2018. Therapeutic options remain extremely limited to those that are symptom targeting, while no drugs have been approved for the modification or reversal of the disease itself. Risk factors for AD including aging, the female sex, as well as carrying an APOE4 genotype. These risk factors have been extensively examined in the literature, while less attention has been paid to modifiable risk factors, including lifestyle, and environmental risk factors such as exposures to air pollution and pesticides. This review highlights the most recent data on risk factors in AD and identifies gene by environment interactions that have been investigated. It also provides a suggested framework for a personalized therapeutic approach to AD, by combining genetic, environmental and lifestyle risk factors. Understanding modifiable risk factors and their interaction with non-modifiable factors (age, susceptibility alleles, and sex) is paramount for designing personalized therapeutic interventions.

Midlife predictors of active and healthy aging (AHA) among older businessmen

Background

Active and healthy aging (AHA) is an important phenomenon in aging societies.

Aims

Our aim was to investigate midlife predictors of AHA in a socioeconomically homogenous male cohort.

Methods

In 2010, AHA was defined in the Helsinki Businessmen Study (men born in 1919–1934) with six criteria: (1) being alive, (2) responding to the mailed survey, (3) no reported cognitive problems, (4) feeling of happiness, (5) no difficulties in activities of daily living (ADL), and (6) no significant chronic diseases. Midlife factors were assessed in 1974 (n = 1759, mean age 47 years). Of the survivors in 2010 (n = 839), 10.0% (n = 84) fulfilled all AHA criteria, whilst 13.7% (n = 115) had chronic diseases but fulfilled other five criteria. Midlife predictors of AHA were analyzed with logistic models.

Results

Of the midlife factors, smoking [Odds ratio (OR) 0.44, 95% confidence interval (CI) 0.25–0.77], higher body mass index (BMI) (OR 0.75, 0.59–0.96), and higher total cholesterol (OR 0.76, 0.60–0.97) prevented significantly full AHA criteria, whereas higher self-rated health (SRH) (OR 1.73, 1.07–2.80) predicted significantly of fulfilling all AHA criteria. Midlife smoking (OR 0.87, 0.84–0.91), higher BMI (OR 0.73, 0.61–0.86), and higher alcohol consumption (OR 0.73, 0.60–0.90) prevented significantly of fulfilling the five AHA criteria with chronic diseases, and higher SRH (OR 1.90, 1.37–2.63) predicted significantly the five AHA criteria (chronic diseases present).

Discussion

Our study suggests that midlife factors, especially good SRH and low levels of cardiovascular risk factors, are associated with AHA.

Conclusions

The study emphasizes the importance of life-course predictors of healthy aging.

Investigation of the prevalence of Cognitive Impairment and its risk factors within the elderly population in Shanghai, China

To investigate the prevalence of cognitive impairment and its risk factors among Chinese elders aged over 80 years, a community-based, cross-sectional study was conducted from May to June 2016 in Shanghai, China. Cognitive function was measured by using Mini-Mental Status Examination. Multiple logistic regression assessed associations between risk factors and cognitive impairment. Of 480 participants, 30% were diagnosed with cognitive impairment. Women [adjusted odds ratio (AOR): 1.71, 95% confidence interval (CI): 1.03-2.83], solitary life (AOR: 3.15, 1.89-5.26), monthly income less than 2000 Chinese yuan (AOR: 3.47, 1.18-10.23) were significantly associated with increased risk of cognitive impairment, compared with men, non-solitary life, and monthly income greater than 4000 Chinese yuan, respectively. Overweight (AOR: 0.59, 0.36-0.97), being physically active at least 60 minutes per day (AOR: 0.59, 0.35-0.95), antihypertensive drugs users (AOR: 0.45, 0.28-0.72), and lipid lowering drugs users (AOR: 0.21, 0.06-0.76) significantly lowered the risk of cognitive impairment, compared with normal weight, inadequate outdoor activity, and non-medication users, respectively. Accordingly, this study found that women, solitary life, lower income was associated with increased risk of cognitive impairment, while overweight, being physically active, and antihypertensive and lipid lowering drugs usage might lower the risk.