Background: The most common type of dementia is an Alzheimer's disease which is a major concern in growing chronic diseases in the geriatric society, and its connection with biochemistry has not been sufficiently understood. Objective: This study aims to evaluate the effects of blood biochemistry on Alzheimer's disease. Method: Eight participants aged 55+ with Alzheimer's disease were analyzed. A cross-sectional work has conducted. Eighty patients have been divided into 2 groups as group A and group B according to laboratory findings including glycosylated hemoglobin, high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol (TC), triglycerides (TGA), vitamin D, folic acid, and vitamin B-12. Mean Mini-Mental State Examination scores between these different 2 groups have been compared. Results: High levels of HDL, vitamin D, and folic acid correlate with cognitive scores, whereas high levels of total cholesterol, HbA1c, LDL show a negative effect on cognition scores. Conclusion: High-density lipoprotein, vitamin D, folic acid, cholesterol, HgA1c, and LDL have an effect on dementia.