Alzheimer’s disease is a brain condition that slowly destroys memory, thinking skills, and the ability to do everyday tasks. It affects millions of people around the world.
The disease happens when harmful proteins called beta-amyloid plaques and neurofibrillary tangles build up in the brain, causing damage to brain cells.
Scientists are always looking for ways to detect Alzheimer’s early, before major symptoms appear. Finding the disease early could help doctors take steps to slow it down. A new study from the University of California San Diego has found something promising—an enzyme in the blood called PHGDH.
PHGDH helps the body make an amino acid called serine, which is needed to build proteins and keep the brain healthy. In this study, researchers found that older adults with high levels of PHGDH in their blood were more likely to have Alzheimer’s disease, even if they hadn’t shown signs of memory loss yet.
The team looked at brain samples from four different groups of people aged 50 and older. Each group had about 40 to 50 people. Some had Alzheimer’s, some had early signs of it, and others were healthy. In all groups, people with Alzheimer’s or early brain changes had higher levels of PHGDH.
Even people who seemed healthy but had high PHGDH levels might have been in the early stages of the disease. The researchers also found that PHGDH levels kept rising as Alzheimer’s got worse. This trend was seen in both human brain samples and in lab mice with Alzheimer’s.
People who did poorly on memory and thinking tests also had higher PHGDH levels. This shows that the enzyme might be linked to how much the brain is affected by the disease.
These results suggest that testing PHGDH levels in the blood could help find Alzheimer’s before symptoms show up. That would give doctors and families more time to plan care and treatments.
But the study also brings up an important concern. Some people take serine supplements to try to prevent or treat Alzheimer’s. Since PHGDH makes serine, and high levels of PHGDH are linked to Alzheimer’s, taking more serine might actually make things worse.
The researchers say we should be cautious and wait for more studies before using serine supplements for brain health.
The study was led by Sheng Zhong and published in the journal Cell Metabolism. It adds to our growing understanding of Alzheimer’s and shows that PHGDH could be a useful early warning sign. More research is needed to understand how PHGDH and serine work in the brain and whether targeting them could lead to better treatments.
While there is still no cure for Alzheimer’s, there are things people can do to lower their risk. Exercising regularly helps keep blood flowing to the brain and reduces inflammation. Eating a healthy diet, especially the Mediterranean diet full of fruits, vegetables, whole grains, nuts, and olive oil, may also protect the brain.
Keeping your brain active by reading, solving puzzles, or spending time with others is also helpful. Managing health problems like high blood pressure, diabetes, and high cholesterol is another important way to protect the brain.
This study is a big step forward in understanding Alzheimer’s and offers hope that one day, we may be able to find and treat it much earlier.
If you care about Alzheimer’s, please read studies about Vitamin D deficiency linked to Alzheimer’s, vascular dementia, and Oral cannabis extract may help reduce Alzheimer’s symptoms.
For more information about brain health, please see recent studies about Vitamin B9 deficiency linked to higher dementia risk, and results showing flavonoid-rich foods could improve survival in Parkinson’s disease.
Copyright © 2026 Knowridge Science Report. All rights reserved.
