With global population aging, cognitive impairment and dementia have become major public health issues worldwide. According to the 2019 World Alzheimer Report by the Alzheimer's Disease International, there are more than 50 million people living with dementia globally, and this number is projected to rise to 152 million by 2050, with one new case occurring every three seconds. Our research is to investigate the intervention effects of perch essence on cognitive function in mild-cognitive impairment patients.

1. Study population: 54 MCI patients were recruited and the inclusion criteria are: (1) aged ≥ 45, (2) diagnosed with mild cognitive impairment by clinical dementia rating (CDR) with a scoring of 0.5, and (3) have the ability to communicate, reading and writing. The exclusion criteria are: (1) diagnosed with dementia, (2) diagnosed with terminal diseases or severe psychological symptoms (lifespan ≤ 2 years, cancer, severe stroke, heart disease, liver cirrhosis, ESRD, severe depression, etc.), (3) Severe blindness, hearing impairment, or communication disability, (4) Branched-chain organic aciduria (e.g., maple syrup urine disease), (5) Individuals who do not consume fish or are allergic to fish products 2. Study design: A two-arm single-blind randomized controlled clinical trial will be performed for 24 weeks and the subjects will be divided in to 2 groups: (1) control group, (2) treatment group. S The treatment group were asked to consume 60mL/packet of perch essence, twice daily for 24 weeks, whereas the control group were provided with the same appearance, flavor, and color of fish stock. Participants were asked to maintain their dietary habit, lifestyle, and used of medication.

3. Outcome assessment:

1. Anthropometry data: height, weight, body mass index

2. Blood biochemistry:

   A. Nutritional status: albumin, total protein, Vitamin B12, folate, magnesium B. Glycemic profiles: fasting blood glucose C. Lipid profiles: total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG).

   D. Complete blood counts: white blood cells (WBC), red blood cells (RBC), hemoglobin (HB), platelet count (PLT), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC).

   E. Brain derived neurotrophic factor (BDNF), malondialdehyde (MDA)

3. Urine test Urine color, appearance, specific gravity, pH, glucose, creatinine

4. Cognitive function: Montreal cognitive assessment (MoCA), Cognitive abilities screening instruments (CASI)

5. Nutrition status Mini-nutritional assessments (MNA), 3-day dietary recall The purpose of the study investigated the intervention of perch essence supplement on cognitive function and its correlation with nutritional status in MCI patients.

Inclusion Criteria:

• aged ≥ 45
• diagnosed with mild cognitive impairment by clinical dementia rating (CDR) with a scoring of 0.5
• have the ability to communicate, reading and writing

Exclusion Criteria:

• diagnosed with dementia
• diagnosed with terminal diseases or severe psychological symptoms (lifespan ≤ 2 years, cancer, severe stroke, heart disease, liver cirrhosis, ESRD, severe depression, etc.)
• Severe blindness, hearing impairment, or communication disability
• Branched-chain organic aciduria (e.g., maple syrup urine disease)
• Individuals who do not consume fish or are allergic to fish products