Do the crossword puzzle -- unless you're good at it
If you've searched the Web for memory-boosting exercises, you may have been urged to play sudoku, take up an instrument, try a brain-teasing video game, or challenge someone to a chess match. However, none will do your brain much good unless the activity is both new to you and difficult. "For good brain health, we need to expose the brain on a daily basis to activities that are novel and complex," explains Paul D. Nussbaum, Ph.D., neuropsychologist and chair of the Prevention Advisory Board for the Alzheimer's Foundation of America. "It's human nature to do what we're good at, but that's just rote processing. Passivity is bad for the brain."

Dr. Nussbaum explains that mental challenges across one's lifespan delay the onset of memory loss and related conditions later in life. "Many of the mental disorders we associate with age really begin years and years before. The message here is that we have to be proactive with our lifestyle early on."

Be a fathead
We spend a lot of time worrying about the fat building up around our belt lines, but we should also be aware of the fat in our brains. "The brain is 60 percent fat, which makes it the fattiest part of the body," explains Nussbaum. "Because we tend to eat the wrong kinds of fat in this country -- and not enough omega-3 fatty acids -- the brain tends to be out of balance." Nussbaum advocates for more "good" fat in the diet, particularly from fish sources, and for consuming whole fruits and vegetables since they are rich in antioxidants.

Only recently has it been recognized that what we eat can actually alter our genetic makeup. In the new area of nutritional neuroscience, researchers are making connections between diet and a number of mental disorders, including Alzheimer's disease, stroke and Parkinson's disease.

Do aerobic exercises
The link between physical exercise and mental health is seldom discussed but easily understood: Every time your heart beats, 25 percent of the blood goes to your brain. Whether you integrate plenty of walking into your daily routine or set aside a few hours per week for running, swimming, calisthenics or even dancing, staying active helps deliver critical payloads of glucose and oxygen to the brain. Nussbaum notes that the brain's hippocampus, which is the hub of the memory process, is particularly sensitive to oxygen deprivation and is the first brain structure to malfunction when a person stops breathing. Recent studies have shown that physical exercise can even promote the growth of new brain cells in the hippocampus.

Plan time to relax
Stress hits the hippocampus, where memory is based. As noted by AARP, negative, damaging and traumatic input can result in structural damage to this sensitive brain area, and therefore to memory. But you can reduce stress through daily meditation, deep breathing, massage, prayer or other modalities. There is an adage among neuroscientists that "what is good for the body is good for the brain." Similarly, the physical effects of stress are closely mirrored by neurological effects.

Join a book group
Sharing a book with a group of friends challenges your brain to absorb, retain and recall new information -- a valuable route when it comes to exploring the "novel and complex" concept outlined by Nussbaum. Critically, it's also an avenue for socialization. Human interaction is a vital component of brain development, which, contrary to earlier understanding, is a lifelong process. Unfortunately, the elderly in our country are commonly isolated, and without regular communication and intimacy the isolated brain tends toward dementia (i.e., memory loss). But the social brain continues to be stimulated. Studies have shown tremendous creativity and intellectuality among older people who are well connected to friends and family.