Scientists are always searching for ways to detect Alzheimer’s disease early, long before memory problems begin. Alzheimer’s is one of the most common forms of dementia, a condition that slowly affects memory, thinking, and daily life.
Because symptoms often appear late, early detection is very important. It gives people more time to plan, receive support, and possibly slow the disease.
A new study from NYU Langone Health suggests that a simple blood test may help identify people at risk much earlier than before. This test looks at a measure called the neutrophil to lymphocyte ratio, or NLR. While the name may sound complex, the idea behind it is simple.
Our blood contains different types of white blood cells that help fight infection. Neutrophils are one type, and they act as first responders when the body faces infection or injury. Lymphocytes are another type, and they play a key role in long-term immune defense. The NLR is simply the ratio between these two types of cells.
Doctors can easily calculate this ratio using a common blood test called a complete blood count. This test is already widely used in hospitals and clinics, so the information is often already available.
In the study, researchers looked at health data from nearly 400,000 people across two large health systems. They focused on individuals aged 55 and older who had blood test results before any diagnosis of dementia. Then, they tracked whether these individuals later developed Alzheimer’s disease or other forms of dementia.
The results showed a clear pattern. People with higher NLR levels were more likely to develop dementia in the future. This was true for both short-term and long-term risk. In other words, even before any memory problems appeared, changes in the immune system could already be detected.
The study was published in the journal Alzheimer’s & Dementia. It is one of the largest studies to explore the link between immune cells and dementia risk in humans.
Researchers also found that the risk was higher in certain groups. Women showed a stronger link between high NLR and dementia risk. Hispanic patients also showed higher risk, although the reasons are not yet fully understood. It could be due to genetic factors or differences in access to healthcare.
The findings are important because they suggest that inflammation in the body may play a role in Alzheimer’s disease. Neutrophils, while helpful in fighting infection, can also cause damage if they are too active. Over time, this damage may affect blood vessels and brain tissue.
Previous studies in animals have shown that neutrophils may speed up the development of Alzheimer’s disease. In humans, signs of inflammation have been found in the brains of patients with dementia. However, it has been difficult to study neutrophils directly because they only live for a short time in the body.
This new research adds strong evidence that the immune system is involved in brain health. However, the researchers stress that NLR alone cannot predict dementia. It should be used together with other risk factors, such as age, genetics, and lifestyle.
In the future, doctors may use NLR as an early warning sign. People with high levels could be offered more detailed brain tests or early treatments. This could help delay or reduce the impact of the disease.
At the same time, more research is needed. Scientists are still trying to understand whether neutrophils directly cause damage or simply reflect other changes in the body.
Overall, this study highlights a simple but powerful idea. A routine blood test may offer clues about brain health many years before symptoms begin. If confirmed by further research, this could change how doctors detect and manage Alzheimer’s disease.
In reviewing the study, the findings are promising because they are based on a very large sample size, which increases confidence in the results. However, the study shows a connection, not a direct cause.
This means high NLR does not necessarily cause dementia, but it may signal underlying processes linked to the disease. More research is needed to confirm whether targeting inflammation can prevent or slow Alzheimer’s.
If you care about Alzheimer’s disease, please read studies that bad lifestyle habits can cause Alzheimer’s disease, and strawberries can be good defence against Alzheimer’s.
For more information about brain health, please see recent studies that oral cannabis extract may help reduce Alzheimer’s symptoms, and Vitamin E may help prevent Parkinson’s disease.
Source: NYU Langone Health. C
