7 blood markers to prevent Alzheimer’s before it starts

Alzheimer’s is a progressive neurodegenerative disorder that primarily affects memory, thinking, and behavior, occurring in older adults post 65. A part of dementia, the condition is characterized by the buildup of abnormal protein deposits (plaques and tangles) in the brain, leading to the death of nerve cells and disruption of communication between them. The condition is not reversible, and symptoms worsen with time. However, there are certain blood markers that can predict Alzheimer’s and early detection can be crucial in stemming its growth. Take a look…Fasting InsulinInsulin is a hormone that regulates blood sugar. Studies show that both very low and very high fasting insulin levels can increase the risk of dementia, including Alzheimer’s. Low insulin levels may indicate a different risk of dementia, other than diabetes-related risk. Monitoring fasting insulin helps identify people at risk even if they do not have diabetes currently.High-Sensitivity C-Reactive Protein (hs-CRP)Hs-CRP is a marker of inflammation in the body. Inflammation is linked to brain changes in Alzheimer’s. Some studies suggest that higher hs-CRP levels might protect brain structure in people who already have cognitive impairment, possibly by activating repair mechanisms. Still, abnormal hs-CRP levels signal that inflammation should be monitored and managed to reduce Alzheimer’s risk.HomocysteineHomocysteine is an amino acid that can be linked to higher Alzheimer’s risk. High homocysteine levels can damage blood vessels and brain cells, worsening cognitive decline. Studies show Alzheimer’s patients often have about 30% higher homocysteine than healthy people. Lowering homocysteine by improving folate intake and other B vitamins may help reduce this risk.Omega-3 IndexOur brain is almost 60% fat. Omega-3 fatty acids, especially EPA and DHA found in fish oil, are essential for brain health. A higher omega-3 index in blood is linked to better memory, learning, and brain blood flow. Taking omega-3 improves cognitive function, particularly in older adults and can help in preventing dementia. Omega-3s also reduce brain inflammation and protect nerve cells from damage.Vitamin D (25-Hydroxyvitamin D)Low vitamin D levels are associated with a higher risk of dementia and Alzheimer’s disease. Research shows that for every 10 nmol/L increase in vitamin D levels, the risk of dementia decreases by about 5-7%. Maintaining adequate vitamin D through sunlight exposure, diet, or supplements supports brain health and may help prevent Alzheimer’s.ApoE Genotype and Lipid PanelThe ApoE gene comes in different forms, with the ε4 variant being a major genetic risk factor for late-onset Alzheimer’s. ApoE helps transport cholesterol and fats in the body and brain. People with the ε4 allele have higher Alzheimer’s risk, while ε2 is protective. Along with genetic testing, checking blood lipids (cholesterol, triglycerides) can also be a marker for early dementia risk.Gamma-Glutamyl Transferase (GGT)GGT is an enzyme linked to liver function and oxidative stress. Elevated GGT levels in blood are associated with increased risk of dementia and Alzheimer’s. High GGT may reflect harmful oxidative damage and inflammation affecting the brain. Monitoring GGT can help identify people at risk.Sources:Highly accurate blood test diagnoses Alzheimer’s disease, Washington University & Lund University, 2025 Association of hs-CRP and Alzheimer’s disease, PMC, 2018 Plasma homocysteine levels and risk of Alzheimer disease, Neurology, 2004 The omega-3 index in Alzheimer’s disease, PMC, 2022