Alzheimer’s disease may be caused by the breakdown of a protective barrier in the body that allows fatty substances to accumulate in the body. to accumulate in the brain, according to a recently published study.
A new explanation, called the “lipid invasion model,” argues that lipids that enter the brain due to the breakdown of the blood-brain barrier – a dense system of small blood vessels in the brain that only allow a small number of essential substances – is the determining cause of the degenerative disease that affects millions of people worldwide.
The hypothesis is published in the Journal of Alzheimer’s Disease Reports and might open up new possibilities for diagnosis or treatment. The theory also supports the idea that certain lifestyle changes might reduce the risk of Alzheimer’s disease by reducing the impact on the blood-brain barrier and the resulting brain damage in people with the disease.
A healthy blood-brain barrier is incredibly important for the proper functioning of our brain. If the barrier is damaged, as it is in people with Alzheimer’s disease, external lipids like cholesterol and fatty acids have the opportunity to break through.
“These external lipids are handled differently than those typically found in the brain. My theory proposes that these invading lipids lead to brain damage, such as brain shrinkage, and the development of amyloid plaques and ‘tau tangles’, which cause the hallmark behaviors of Alzheimer’s disease, such as memory loss. , sleep disturbances and paranoia. »
Dr Jonathan Rudge, postdoctoral researcher at the University of Reading and author of the study
The presence of excess lipids in the brain cells of patients with Alzheimer’s disease is a piece of original research published by Alois Alzheimer in 1906, but has been the subject of relatively little research since.
The new study pulls together previous research to present a new explanation for the cause of the condition. It follows ten years of research and suggests that the risk factors commonly associated with Alzheimer’s disease are the same as those that damage the blood-brain barrier: old age, head trauma, hypertension, smoking, obesity, diabetes, lack of chronicle of sleep and stress.
She suggests this is why footballers and boxers are particularly at risk, and why the disease mainly affects older people, because in both cases the blood-brain barrier has been damaged or worn down.
There are two types of Alzheimer’s disease: the relatively rare, early-onset inherited form and the late-onset, non-hereditary form associated with aging. The latter form is becoming more common as people live longer, but the current explanation, known as the amyloid hypothesis, relates more to the rarer inherited form.
According to this explanation, the disease is caused by excessive levels of a protein called beta-amyloid. The lipid invasion model supports this hypothesis to some extent, but argues that in the late-onset form, beta-amyloid is only one of the factors that damage the blood-brain barrier, allowing lipids external to penetrate.
The lipid invasion model opens new avenues of research for the detection, prevention and treatment of disease. It may have parallels with other neurodegenerative diseases, such as Parkinson’s disease and motor neurone disease, which also disproportionately affect older people and people who play certain sports, and which may also be associated with brain damage. the blood-brain barrier.
Source :
Journal reference:
Rudge, JD, (2022) A New Hypothesis for Alzheimer’s Disease: The Lipid Invasion Model. Journal of Alzheimer s Disease Reports. doi.org/10.3233/ADR-210299.
