World Alzheimer’s Day 2025: How Alzheimer’s Changes the Brain – Expert Answers

New Delhi, 19 September, 2025: Every year, World Alzheimer’s Day is observed on September 21 to raise awareness about Alzheimer’s disease and its devastating impact on individuals, families, and communities. Alzheimer’s is the most common form of dementia, affecting millions worldwide, and its prevalence is rising at an alarming rate. But what exactly happens inside the brain when someone develops Alzheimer’s? Experts explain how this progressive condition alters brain function, memory, and behavior.

What Is Alzheimer’s Disease?

Alzheimer’s is a neurodegenerative disorder that gradually destroys brain cells and impairs cognitive abilities. It primarily affects memory, thinking, language, and the ability to perform daily tasks. While age is the biggest risk factor, Alzheimer’s is not a normal part of aging—it is a disease with distinct biological changes in the brain.

How Alzheimer’s Affects the Brain – Expert Insights

1. Formation of Plaques and Tangles
   • In Alzheimer’s, abnormal protein deposits—amyloid plaques and tau tangles—build up between nerve cells.
   • These disrupt communication between neurons and interfere with normal brain function.
2. Neuron Damage and Cell Death
   • Healthy neurons transmit signals that control memory and learning.
   • In Alzheimer’s, neurons shrink, lose connections, and eventually die, leading to brain tissue loss.
3. Shrinkage of Brain Regions
   • The hippocampus, responsible for memory formation, is one of the first regions affected.
   • As the disease progresses, the cerebral cortex, which handles reasoning, language, and judgment, also shrinks.
4. Decline in Neurotransmitters
   • Alzheimer’s reduces levels of acetylcholine, a vital neurotransmitter for learning and memory.
   • This decline further worsens cognitive decline.
5. Impact on Blood Flow and Inflammation
   • Alzheimer’s patients often experience reduced blood flow to the brain and chronic inflammation, which accelerates neuronal damage.

Symptoms That Reflect Brain Changes

The structural and chemical changes in the brain manifest as symptoms such as:

• Memory loss and confusion
• Difficulty in problem-solving or decision-making
• Trouble recognizing familiar faces or places
• Language and communication difficulties
• Behavioral changes, including anxiety, aggression, or depression

As the disease advances, individuals may lose the ability to perform even simple daily tasks.

Can Alzheimer’s Be Prevented?

There is currently no cure for Alzheimer’s, but experts highlight that lifestyle factors may delay or reduce risk. These include:

• Regular physical activity
• A brain-healthy diet rich in antioxidants and omega-3 fatty acids
• Staying mentally active through reading, puzzles, or learning new skills
• Quality sleep and stress management
• Regular medical check-ups for heart and brain health

Alzheimer’s is not just about memory loss—it is a complex disease that fundamentally changes the structure and function of the brain. On World Alzheimer’s Day 2025, experts urge people to spread awareness, support ongoing research, and adopt healthier lifestyles to protect brain health.

While the disease remains incurable, understanding how it affects the brain is the first step toward compassion, care, and hope for millions of families worldwide.