Promising Alzheimer's Marker in Blood Prompts Warning About Brain-Boosting Supplements

Elevated levels of PHGDH in the blood could signal the earliest stages of Alzheimer's disease. Researchers caution older adults against using "brain-boosting" supplements that contain serine due to its link to PHGDH. As PHGDH is a key enzyme in serine production, elevated PHGDH levels results in increased serine levels in the brain.