According to the research team, the biomarkers that are always found in the blood can help in predicting whether a person would have Alzheimer’s within the duration of next three years with an accuracy level of 90%. These biomarkers include 10 fats or lipids that can aid in estimating the occurrence of either Alzheimer’s or mild cognitive impairment featuring reduced thinking ability and memory loss.
One of the researchers, Dr. Howard Federoff who is the dean of Georgetown University School of Medicine said, “Low levels of these fats can predict looming dementia symptoms with notable accuracy. It is unknown to us why the level of all those 10 lipids is lower, which indicate the upcoming cognitive impairment. Moreover, we cannot associate this directly to our present knowledge of the Alzheimer’s pathobiology.”
The research featured 525 healthy subjects who were aged 70 or older. They all went through a full blood exam as well as through neurocognitive tests. The research team followed the subjects for a period of five years. During this time, 74 individuals became the patients of mild Alzheimer's disease. The blood samples of these people were then compared to the blood of those subjects who remained unaffected. They found that those who developed dementia later started having lower levels of 10 lipids.
The research team then conducted a second study to test the forecasting power of those lipids on a separate set of 40 participants. This study showed that the blood test could identify individuals who would witness mild cognitive impairment in near future. Notably, the precision level of the blood test remained the same even after conducting a genetic test to identify an altered version of the ‘APOE’ gene that can lead to Alzheimer's. Indeed, it was found that the test forecasted dementia with better precision than the gene test alone. Commenting on this finding, Federoff said that such accurate tests identifying individuals who will finally develop Alzheimer's are more likely to aid in obtaining a cure for the ailment.
The Director of R&D at the Alzheimer’s Society, Dr Doug Brown, also commented that this discovery is appreciable, as it has brought forward something that could positively affect the lives of thousands of dementia patients. The findings of this research is already published in the Nature Medicine Journal that has marked it as the first study to expose the differences in biomarkers between those who are suffering from the disease and those who are cognitively normal.
According to Maria Carrillo who is the Vice President at the Alzheimer's Association, this new blood test could be easier to deal with, than the presently known tests for diagnosing the early onset of dementia. She also shared, “These biomarkers would also prove to be useful; it is less invasive, more accessible, and cost effective. However, more research is urgently needed in this area."
The study only exposed an association between increased vulnerability to dementia and lower lipid levels. However, it did not establish the cause-and-effect relationship.