2 . Overeating
It causes hardening of the brain arteries, leading to a decrease in mental power.

3. Smoking
It causes multiple brain shrinkage and may lead to Alzheimer disease.

4. High Sugar consumption
Too much sugar will interrupt the absorption of proteins and nutrients causing malnutrition and may interfere with brain development.

5. Air Pollution
The brain is the largest oxygen consumer in our body. Inhaling polluted air decreases the supply of oxygen to the brain, bringing about a decrease in brain efficiency.

6. Sleep Deprivation
Sleep allows our brain to rest. Long term deprivation from sleep will accelerate the death of brain cells.

7. Head covered while sleeping
Sleeping with the head covered increases the concentration of carbon dioxide and decrease concentration of oxygen that may lead to brain damaging effects.

8. Working your brain during illness
Working hard or studying with sickness may lead to a decrease in effectiveness of the brain as well as damage the brain.

9. Lacking in stimulating thoughts
Thinking is the best way to train our brain, lacking in brain stimulation thoughts may cause brain shrinkage. Crosswords and Sudoku provide good exercises.

10. Talking Rarely
Intellectual conversations will promote the efficiency of the brain.