A study reported in 2005 showed that even older Americans may improve their memory by instituting a memory-improvement plan consisting of regular mental exercises (working crossword puzzles, word games, brainteasers, and the like), daily physical activity, a healthier diet, and stress reduction.

Stress
Without a doubt, one of the most common reasons that healthy people find themselves becoming forgetful is stress. And it’s not just major, life-changing stress that affects learning and memory. Most of us never realize how much of a toll the day-to-day irritations, hassles, and annoyances can take. Fortunately, high stress-hormone levels over the short term don’t appear to do permanent damage to the brain. As your stress eases or as you employ coping techniques, you should find that your memory improves. On the other hand, there is some evidence to suggest that prolonged exposure to unmitigated stress may damage the hippocampus, making it less able to signal the body to turn off the stress hormones, leading to a vicious cycle of higher and higher stress-hormone levels and further decay of memory and cognition. In time, the hippocampus may actually shrink.

There’s another reason why you may not remember so well when you are under a lot of stress, and it has to do with paying attention. In order to record information well enough to form a memory, you have to be able to focus on the subject you want to remember. Anything that interferes with your ability to pay attention, therefore, will impair your memory. As the sources of your stress monopolize your thoughts, you simply don’t record information the way you normally would, and if the information never gets properly stored to begin with, there won’t be a memory there to retrieve.

Exercise
Studies have found that people who exercise frequently have a distinctive brain-wave pattern, characterized by steep peaks and valleys, that is associated with alertness. These high-exercise folks are better at blocking out distractions and focusing, which means that they are better at paying attention to material that they want to remember and better at retrieving those memories when needed. Research has also found that aerobic exercise can help maintain short-term general and verbal memory. This type of memory is especially important when you want to recall names, directions, and telephone numbers or match a name with a face. Also the results of research reported in March of 2007 suggest an even more impressive role for exercise: building new cells in a specific region of the brain that is associated with the age-related decline in memory that normally begins sometime around age 30.

Sleep
Recent research, especially studies using high-tech tools — such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) — has begun to reveal much more information about the importance of sleep to memory. Such research suggests that it is during sleep that the brain consolidates the initially fragile memories made during the day, reinforcing them and “uploading” them, so to speak, for long-term storage. Once again our old friend the hippocampus appears to play an essential part in the process, storing the day’s memories until they can be consolidated at night. Sleep also facilitates or improves the brain’s ability to remember both declarative information, such as facts and events, and procedural information, such as how to play the scales on a piano keyboard.

Diet
The quality of the diet appears to affect brain health and function, including memory. The best diet for your brain is, basically, the kind that’s also healthy for the rest of your body — a well-balanced diet, filled with whole grains, a wide variety of colorful fresh fruits and vegetables, and moderate amounts of protein, that supplies just enough calories to fuel your daily activities. That diet should also include some fat such as monounsaturated fats and polyunsaturated fats that are high in omega-3 fatty acids but not the saturated fats.

A brain-healthy, memory-wise diet should also provide sufficient amounts of the vitamins and minerals the body needs for health. Especially Vitamin B, C, E, and Magnesium.

Source: Richard C. Mohs, PhD; How Stuff Works