Alzheimer’s disease is a neurodegenerative disease that seems to start well before symptoms first appear. There is currently no treatment, but there are options with potential.
According to the WHO1, Alzheimer’s disease affects more than 35 million people around the world. This number is expected to almost double every 20 years, reaching 115.4 million in 20502.
Memory loss: the first visible symptom of the disease
In addition to the characteristic memory loss, Alzheimer’s disease can also cause speech and comprehension difficulties, attention and concentration problems, loss of dexterity (apraxia), and, in some cases, problems recognizing objects or faces (agnosia). Cognitive symptoms get worse over time and behavioral symptoms start to appear, such as anxiety, apathy, irritability, sleeping disorders, disinhibition, and agitation2 .
From a scientific perspective
Two kinds of lesions are characteristic of Alzheimer’s disease: the abnormal accumulation of beta-amyloid peptide plaque deposits and neurofibrillary degeneration. Although the causes of these phenomena remain unknown, the involvement of intestinal microbiota is being studied. Certain intestinal bacteria seem to produce amyloid peptides similar to those observed in the brains of these patients, which accelerate cerebral inflammation3 involved in the disease.
Risk factors identified
Several genetic and environmental risk factors have been identified2: high blood pressure, high cholesterol, tobacco use, sedentary lifestyle, unbalanced diet, and lack of cognitive stimulation.
Promising prospects for therapy
A diagnosis of Alzheimer’s disease, established during a specialized memory consultation, relies on various exams: neuropsychological exam, MRI, lumbar puncture2, etc.
Although there is currently no treatment, immunotherapy4 appears to be a promising option. Changing the microbiota by affecting diet and adding probiotics and prebiotics may prevent or reduce the risk of cognitive decline3,5 .
1. La démence. OMS. Avril 2016. http://www.who.int/mediacentre/factsheets/fs362/fr/
2. L'association pour la recherche sur Alzheimer http://alzheimer-recherche.org/wp-content/uploads/2015/01/FRA-Broch-instit-2015.pdf
3. Pistollato F et al. M. Role of gut microbiota and nutrients in amyloid formation and pathogenesis of Alzheimer disease. Nutr Rev. 2016 Oct;74(10):624-34. doi: 10.1093/nutrit/nuw023
4. L'immunothérapie pour soigner la maladie d'Alzheimer. Inserm, décembre 2016 http://presse.inserm.fr/limmunotherapie-pour-traiter-la-maladie-dalzheimer/26111/ et Interleukin-2 improves amyloid pathology, synaptic failure and memory in Alzheimer’s disease mice, Brain, 20 décembre 2016 http://brain.oxfordjournals.org/content/early/2016/12/20/brain.aww330
5. Microbiote intestinal et santé. Inserm. http://www.inserm.fr/thematiques/physiopathologie-metabolisme-nutrition/dossiers-d-information/microbiote-intestinal-et-sante