Alzheimer’s disease is the most common cause of dementia and one of the biggest health challenges of aging societies.
In the United States alone, about 7.2 million people aged 65 and older are living with the disease, according to the Alzheimer’s Association.
Alzheimer’s slowly damages memory, thinking ability, and daily functioning. At first, people may only notice small changes, such as forgetting names or misplacing items.
As the disease progresses, it becomes harder for individuals to recognize loved ones, communicate clearly, or care for themselves.
Because Alzheimer’s develops slowly over many years, doctors and scientists have been working hard to find ways to detect it as early as possible. Early detection is important because treatments work best before severe brain damage has occurred.
Currently, many diagnostic tests focus on measuring two specific proteins linked to Alzheimer’s disease: amyloid beta and phosphorylated tau.
These proteins can build up in the brain and form plaques and tangles that interfere with normal brain function. Blood tests and spinal fluid tests can measure the amount of these proteins, helping doctors identify people who may have Alzheimer’s.
However, scientists increasingly believe that simply measuring the amount of these proteins may not capture the earliest biological changes that occur in the disease.
A team of researchers at Scripps Research has now developed a different kind of blood test that examines something new: the shape or folding of proteins circulating in the bloodstream. Their findings were published in the scientific journal Nature Aging on February 27, 2026.
Proteins are essential building blocks of the body. They perform many important tasks, such as carrying molecules, sending signals, and supporting the structure of cells. For proteins to work properly, they must fold into the correct three-dimensional shape. If the folding process goes wrong, proteins may lose their normal function or become harmful.
The system that keeps proteins properly folded is known as proteostasis. This system includes many biological processes that help produce proteins, fold them correctly, and remove damaged ones.
As people grow older, the body’s ability to maintain this system can weaken. When proteostasis breaks down, proteins are more likely to fold incorrectly, which can contribute to diseases of aging, including neurodegenerative conditions like Alzheimer’s.
Scientists have long known that misfolded proteins accumulate in the brains of people with Alzheimer’s disease. Amyloid plaques and tau tangles are examples of such abnormal protein structures.
Based on this knowledge, the Scripps Research team wondered whether structural changes might also appear in proteins circulating in the blood. If so, these changes could potentially serve as early warning signs of Alzheimer’s.
To explore this possibility, the researchers analyzed blood plasma samples from 520 participants. The participants were divided into three groups. One group consisted of cognitively normal adults with no signs of memory problems.
The second group included individuals with mild cognitive impairment, a condition that often represents an early stage of Alzheimer’s disease. The third group consisted of patients who had already been diagnosed with Alzheimer’s.
The scientists used a powerful laboratory technique called mass spectrometry to study the structure of proteins in the blood. This method allowed them to detect whether certain areas of proteins were exposed or hidden within the folded structure. These differences reveal whether the protein’s shape has changed.
After collecting the structural information, the researchers used machine learning to analyze patterns across the large dataset. Machine learning is a type of artificial intelligence that can detect complex relationships in data that might be difficult for humans to identify.
The results revealed a clear trend. As Alzheimer’s disease progressed, some blood proteins appeared to become less structurally “open.” In other words, their folded shapes changed in measurable ways. Interestingly, these structural changes provided more useful information about disease stage than simply measuring the total amount of the proteins.
Among the many proteins examined, three stood out as strongly linked to Alzheimer’s status. The first protein was C1QA, which plays a role in immune system signaling.
The second was clusterin, a protein involved in helping other proteins fold correctly and in clearing amyloid from the brain. The third was apolipoprotein B, which helps transport fats in the bloodstream and contributes to the health of blood vessels.
Changes in specific locations within these three proteins allowed the researchers to distinguish between healthy participants, those with mild cognitive impairment, and those with Alzheimer’s disease.
When the model analyzed all three proteins together, it identified disease status with about 83 percent overall accuracy. When comparing two groups directly, such as healthy individuals versus those with mild cognitive impairment, accuracy rose above 93 percent.
The researchers also tested whether the method could track Alzheimer’s over time. In blood samples taken months apart, the protein structure score identified disease status with about 86 percent accuracy.
The score also closely matched the results of cognitive tests that measure memory and thinking ability. There was also a moderate relationship between the protein score and brain imaging results that show shrinkage of brain tissue.
These findings suggest that studying protein structure in blood may provide valuable new information about Alzheimer’s disease. Unlike existing tests that focus mainly on amyloid and tau levels, this approach examines broader biological changes linked to the body’s protein maintenance system.
From an analytical perspective, the study offers an exciting new direction for Alzheimer’s research. The idea that changes in protein folding could serve as early biomarkers is scientifically plausible because protein misfolding is known to play a key role in many neurodegenerative diseases.
The high accuracy reported in distinguishing disease stages suggests that structural protein analysis may complement existing diagnostic tools.
However, the findings should still be interpreted cautiously. The study included 520 participants, which is a strong starting point but still relatively small for developing a clinical diagnostic test.
Larger studies across diverse populations will be necessary to confirm the reliability of the method. Researchers will also need to follow participants for longer periods to determine whether the test can predict Alzheimer’s before symptoms appear.
If future studies confirm these results, this type of blood test could help doctors diagnose Alzheimer’s earlier, monitor how the disease progresses, and evaluate whether treatments are working. Researchers are also exploring whether similar protein structure analysis could be used to detect other diseases, including Parkinson’s disease and certain types of cancer.
Overall, the study represents an important step toward understanding Alzheimer’s from a new biological perspective. By focusing on how proteins change shape rather than simply how many are present, scientists may gain a deeper understanding of the disease and open new paths for early detection and treatment.
If you care about Alzheimer’s disease, please read studies about the protective power of dietary antioxidants against Alzheimer’s, and eating habits linked to higher Alzheimer’s risk.
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