that stress reduces the number of neurons in the prefrontal cortex and hippocampus.
Avoid drugs, alcohol, and other neurotoxins. Drug use and excessive alcohol consumption are associated with synapse destruction. Exposure to hazardous chemicals such as heavy metals and pesticides can cause this effect.
Do exercises. Regular physical activity helps to improve the oxygenation of brain cells, which is a vital factor in the formation and growth of synaptic connections.
Stimulate your brain. Researchers have found that older people who participate in mentally stimulating activities are less likely to develop dementia, and that more educated people tend to have more synaptic connections in the brain.
9. A good night's sleep can improve your memory.

You've probably heard of the many reasons why a person needs a good night's sleep. Since the early 1960s, researchers have noted an important link between sleep and memory. In one classic experiment conducted in 1994, researchers found that depriving participants of sleep led to a deterioration in their abilities.
In addition to this, sleep also plays a significant role in learning new information. One study found that depriving students of sleep after learning a new skill led to a significant deterioration in that skill after three days.
Researchers have found, however, that sleep has a much stronger effect on procedural memory than declarative memory. Procedural memories are associated with movement and perception, while declarative memories are associated with remembering facts.
"If you're going to take the 72 irregular French verb test tomorrow, you might as well be cramming late," said Robert Stickgold, a professor of psychiatry at Harvard Medical School, in an article published in Monitor on Psychology. “But if they decide to cheat and ask you to explain the difference between the French Revolution and the Industrial Revolution, you will understand that it would be better to get some sleep.”

10. Memory problems in old age can be avoided.

Alzheimer's disease and other age-related memory problems occur in many older people, but memory loss in old age is not entirely inevitable. Some abilities tend to decline with age, but researchers have found that people in their 70s often perform cognitive ability tests the same way they do in their 20s. Some types of memory even improve with age.
Researchers are still trying to understand why it is that some older people manage to maintain memory in excellent condition, while others are forced to put up with forgetfulness; and several factors have already been established. First, many experts believe that there is a genetic component responsible for the retention of data in memory in old age. Secondly, lifestyle plays an important role.
“I think a lot of this is due to the interplay of nature and nurture,” Dr. Bruce S. McEwan told The New York Times. professor at Rockefeller University in New York. “The genetic vulnerability of memory makes it more likely that this will happen.”
So what can be done to prevent the negative effects of aging on memory?
There is simply no way to quickly get rid of memory problems. For your memory to function well over time, researchers believe you need to avoid stress, stay active, and exercise your memory to reduce your risk of memory loss in old age.