What causes Alzheimer’s disease? It’s still an enigma. Researchers, however, have just discovered an element that could increase the risk to get the disease: the state of the liver.
Today in the United States, about 5.3 million people live with Alzheimer’s disease, with 5.1 million of them being 65 years old or older according to the the Alzheimer’s Association. Meanwhile, researchers are working hard to understand what are the main causes of this neurodegenerative disease, which is the 6th leading cause of death in the country.
The herpes virus, high blood pressure or too long hours of sleep… Recently, studies have identified certain risk factors. This week at the Alzheimer’s Association’s annual conference in Chicago, a team of researchers, led by Dr. Mitchel A. Kling (associate professor of psychiatry at the University of Pennsylvania in Philadelphia), has presented the conclusions of his last study. The researchers have identified an organ that would play a role in the development of the disease: the liver.
Plasmalogens are a type of phospholipid produced in the liver. They play a key role in maintaining healthy brain cells. They are sent from the liver to the brain (and other organs) through the blood. The researchers wanted to know if a reduced rate of these plasmalogens could increase the risk of Alzheimer’s disease.
For this, two groups of participants were evaluated. Each group was made up of people with Alzheimer’s disease or other cognitive impairments, and people deemed “cognitively normal”. The researchers found that a reduced level of plasmalogens corresponded to the high level of tau protein, already identified as an index of Alzheimer’s disease.
“This research shows that age-related plasmalogen deficiency could lead to an increased risk of Alzheimer’s disease because the liver can not do enough,” says Dr. Kling.
According to the team of researchers, these findings could explain why some patients with Alzheimer’s disease, who consume fish oil or docosahexaenoic acid (or DHA, a fatty acid of the family omega-3 ), do not see their cognitive functions improve while these products are known to keep our brain healthy. This would be because their liver can not ingest the fatty acids in the plasmalogens.