Exposure to polychlorinated biphenyls and organochlorine pesticides and risk of dementia, Alzheimer’s disease and cognitive decline in an older population: a prospective analysis from the Canadian Study of Health and Aging

Medehouenou, Thierry Comlan Marc; Ayotte, Pierre; Carmichael, Pierre-Hugues; Kröger, Edeltraut; Verreault, René; Lindsay, Joan; Dewailly, Éric; Tyas, Suzanne L.; Bureau, Alexandre; Laurin, Danielle

doi:10.1186/s12940-019-0494-2

Cited by 42 publications

(26 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…On the other hand, data from the Canadian Study of Health and Aging [48] showed instead a reduced prevalence of AD (2023 participants, 399 with AD) with elevated plasma pesticide (polychlorinated biphenyls (PCB) and organochlorine (OC)) metabolite levels [49]. A more recent analysis of the cohort (513 subjects, 108 with AD) also affirmed that there is no association of PCB and OC pesticides with the risk of dementia and AD, although a posteriori analyses showed that DDE levels are related to a higher cognitive decline in time [50].…”

Section: Epidemiological Links Between Pesticide Exposure and Alzheimmentioning

confidence: 99%

Neuropathological Mechanisms Associated with Pesticides in Alzheimer’s Disease

Tang

2020

Toxics

View full text Add to dashboard Cite

Environmental toxicants have been implicated in neurodegenerative diseases, and pesticide exposure is a suspected environmental risk factor for Alzheimer’s disease (AD). Several epidemiological analyses have affirmed a link between pesticides and incidence of sporadic AD. Meanwhile, in vitro and animal models of AD have shed light on potential neuropathological mechanisms. In this paper, a perspective on neuropathological mechanisms underlying pesticides’ induction of AD is provided. Proposed mechanisms range from generic oxidative stress induction in neurons to more AD-specific processes involving amyloid-beta (Aβ) and hyperphosphorylated tau (p-tau). Mechanisms that are more speculative or indirect in nature, including somatic mutation, epigenetic modulation, impairment of adult neurogenesis, and microbiota dysbiosis, are also discussed. Chronic toxicity mechanisms of environmental pesticide exposure crosstalks in complex ways and could potentially be mutually enhancing, thus making the deciphering of simplistic causal relationships difficult.

show abstract

Section: Epidemiological Links Between Pesticide Exposure and Alzheimmentioning

confidence: 99%

Neuropathological Mechanisms Associated with Pesticides in Alzheimer’s Disease

Tang

2020

Toxics

View full text Add to dashboard Cite

show abstract

“…It is crucial to have a stable number of "close to unexposed" study subjects in the reference category to estimate a relative risk that is less biased . This methodological issue can explain the findings of Canadian elderly population with relatively high concentrations of POPs, which were discussed above …”

Section: Major Challenges For the Hypothesismentioning

confidence: 99%

“…In this paper, we distinguished between occupational or acciden- Chronic exposure to low-dose POPs was recently linked to cognitive impairment or dementia in the general population, although the results were not completely consistent. 24,[27][28][29][30] In cross-sectional and case-control studies performed on the U.S. general population, serum concentrations of OCPs were found to be related to an increased risk of dementia or cognitive impairment. 24,27 Interestingly, these compounds modified the well-known associations of established risk factors for cognition such as the apolipoprotein E (APOE) genotype, age, and hypertension.…”

Section: Lipophilic Chemical Mixtures As Neurotoxinsmentioning

confidence: 99%

Intensive weight loss and cognition: The dynamics of persistent organic pollutants in adipose tissue can explain the unexpected results from the Action for Health in Diabetes (Look AHEAD) study

Lee

Park

Lee

2020

Alzheimer's & Dementia

View full text Add to dashboard Cite

Objective The aim of this paper is to propose a new hypothesis for the role of lipophilic chemical mixtures stored in adipose tissue in the development of dementia. Specifically, we present how the dynamics of these chemicals can explain the unexpected findings from the Action for Health in Diabetes (Look AHEAD) study, which failed to show long‐term benefits of intentional weight loss on cognition, despite substantial improvements in many known risk factors for dementia. Moreover, we discuss how the role of obesity in the risk of dementia can change depending on the dynamics of these chemicals in adipose tissue. New hypothesis Human adipose tissue is widely contaminated with various neurotoxic chemicals. Typical examples are persistent organic pollutants (POPs), strong lipophilic chemicals with long half‐lives. Both unintentional and intentional weight loss increases the release of POPs from adipocytes into the circulation. As POPs in the blood can easily reach the brain, the intentional weight‐loss group of the Look AHEAD study may have experienced an unappreciated and long‐term disadvantage on their cognition. Additionally, POPs may be involved in the link between obesity and dementia, as dysfunctional hypertrophic adipocytes enhance the release of POPs from adipocytes to the circulation through uncontrolled lipolysis. In contrast, metabolically healthy obese people may have a low risk of dementia because the safe storage of POPs in adipose tissue would decrease the amount of POPs reaching the brain. Major challenges for the hypothesis In human studies, there are practical difficulties involved with measuring POPs in the blood, including high costs and complex assays. As the serum concentrations of POPs are continuously affected by weight loss and gain, prospective studies may require serial measurements of POPs. In in‐vitro and in‐vivo experimental studies, how to simulate the exposure dose, duration, and mixture patterns in humans would be critical. Linkage to other major theories Even though POPs are direct neurotoxins at a high dosage, low‐dose POPs are mitochondrial toxins. Therefore, chronic exposure to low‐dose POPs is linked to known key interrelated mechanisms in the pathogenesis of dementia, such as mitochondrial dysfunction and neuroinflammation.

show abstract

“…), los PCB, el plomo, etc., podrían estar afectando al desarrollo cognitivo de las personas mayores. Sin embargo, existe todavía mucha controversia al respecto 41 , 42 , 43 , 44 .…”

Section: Contaminantes Ambientales Y Salud Mentalunclassified

Salud mental y salud ambiental. Una visión prospectiva. Informe SESPAS 2020

Ordóñez-Iriarte

2020

Gaceta Sanitaria

View full text Add to dashboard Cite

Resumen El ambiente ha sido, desde los albores de la psiquiatría, un factor fundamental en el estudio y la comprensión de las enfermedades mentales. La relación entre genoma y ambiente ha constituido tradicionalmente un tema central en la investigación de la etiopatogenia de los problemas de salud mental y en la concepción misma de esta. En su aplicación a la psicopatología y a la salud mental, la ambiómica psiquiátrica se ha definido como «el estudio de las condiciones y procesos ambientales que promueven la salud mental o incrementan los riesgos de trastornos mentales». Sin embargo, la salud ambiental, al menos en España y en relación con sus competencias dentro del sistema de salud general, ha centrado su atención en los aspectos relativos a los riesgos ligados a la contaminación física, química o biológica del aire, el agua o la tierra, así como a su correlato alimenticio. Aunque los riesgos ambientales, como la calidad del aire, las temperaturas extremas, el ruido, el cambio climático y distintos tóxicos ambientales, pueden desempeñar un papel muy importante, difícilmente pueden ser identificados como elementos etiopatogénicos únicos. Este trabajo revisa la literatura reciente sobre la investigación ambiental y los problemas de morbimortalidad psiquiátrica. Si bien los resultados son poco concluyentes, las futuras líneas de investigación deberían considerar una colaboración interdisciplinaria más ágil, que permita, por un lado, entender mejor la enfermedad mental, y por otro, avanzar desde la salud ambiental «tradicional» a una que contemple los factores ambientales de tipo social abordando el concepto aún poco estudiado de «contaminación social».

show abstract

Exposure to polychlorinated biphenyls and organochlorine pesticides and risk of dementia, Alzheimer’s disease and cognitive decline in an older population: a prospective analysis from the Canadian Study of Health and Aging

Cited by 42 publications

References 40 publications

Neuropathological Mechanisms Associated with Pesticides in Alzheimer’s Disease

Neuropathological Mechanisms Associated with Pesticides in Alzheimer’s Disease

Intensive weight loss and cognition: The dynamics of persistent organic pollutants in adipose tissue can explain the unexpected results from the Action for Health in Diabetes (Look AHEAD) study

Salud mental y salud ambiental. Una visión prospectiva. Informe SESPAS 2020

Contact Info

Product

Resources

About