The notion of "use it of lose it" definitely applies to the brain. Studies have shown that mental acuity and sharpness can stay high if you keep challenging your brain as you age. Not only is this something that's easy to do, but it can be a lost of fun as well. It can be as simple as doing a daily crossword puzzle.

About 25 percent of people age 85 and over suffer from dementia. Approximately one-third of all people over age 60 have memory problems that can be measured and which they notice themselves, Says Dr. Mark Williams, M.D.,  author of the American Geriatrics society's Complete Guide to Aging and Health: "The fear of dementia is stronger than the fear of death."

The good news is that scientists now believe the brain doesn't have to degenerate. So haw can we keep out brains healthy? Important studies provide us with some strategies.

One is physical exercise. Your brain needs oxygen to be healthy. Regular exercise is necessary to bring more oxygen to the brain, and even moderate aerobic exercise, such as long brisk walks and frequently climbing stairs, will accomplish this. 

Another is mental exercise. This can be anything that challenges your brain and makes you think. Watching TV quiz shows such as Jeopardy is a good form of mental exercise. 

Here are some other easy mental exercises that can be fun, too:

• Cryptograms - found in most daily newspapers, the object is to break the code to decipher a message.
• Word scrambles - also in most newspapers, these puzzles consist of words whose letters have been mixed around.
• Hidden words - these puzzles are a block of apparently random letter But on close inspection, you can find hidden words. Sometimes the words run on the diagonal or back ward.
• Word games, such as Scrabble - thinking of words and planning strategies are great brain exercises. 
• Jigsaw puzzles - start with simple ones, then as you become better at piecing them together, go for larger and more complex puzzles. Trying to find how the pieces fit together is great mental stimulation.

In many studies, education was also found to enhance brain function. Here's how you can challenge your brain to keep it functioning at peak performance.
 

• Take a class  you've always wanted to take, but never found the time. Take a home study course, or look into education in cyberspace.
• Teach yourself a skill. Maybe you'd like to learn more about the stock market and work your own investments. Find good books on the subject.
• Go to public letters on subjects that interest you. 
• Take writing classes or write stories and poetry for fun. Language ability has been found to have a possible effect on brain longevity. 
• Study a foreign language. It can be great fun, but also very useful particularly if you travel.
• Read books that challenge you. You may enjoy a good romance novel, but a mystery story may be better for your brain if you try to figure out "who dun-it." Don't stop reading for fun, but do add some challenging reading to your book list.
• Subscribe to weekly news magazines. They educate you and keep you aware of current events, which stimulates your brain and helps you stay oriented to time, date and place.

A lot of research is being conducted into "smart drugs," medications to treat brain aging. We may eventually have a slew of drugs available for preserving brain function. In addition to new chemical compounds, scientists are finding that commonly used drugs and substances such as nicotine, prednisone, ibuprofen and estrogne may positively affect our brains as we age.

But researchers advise that we are far from accurately and safely enhancing our brain power with chemicals. While the first wave of memory improving drugs show much promise, their effect may be considered modest. 

Here are some of the more promising drugs being studied for brain longevity:
 

• Estrogen: Scientist say that estrogen may stimulate brain neurons to grow more branches. A study of estrogen and Alzheimer's disease by the Nation Institutes of Health (NIH) has also been lauched.
• Anti inflammatory drugs, such as prednisone, aspirin and ibuprofen. These show promise for prevention of Alzheimer's disease. 
• Nicotine has been shown to enhance brain function , but scientists say smoking's dangers are far greater than nicotine's benefits. Safer methods of drlivering nicotine and  being studied.
• Ampakines are a class of drugs that may have an immediate effect on our ability to learn or create new memories. The drugs appear to have no side effects as shown in a small study on human subjects. There is still much research to be done, however.
• Sam, or S-adenosylmethionine is the ultimate nutrient for brain protection, says james South, in International Anti-Aging Systems.

Currently, some drugs shown to enhance brain function are available in Europe and are widely prescribed by doctors there. But few have made their way to approval in the United States. 

Some treatments, however are becoming available that are classified as supplements rather than prescription drighs, such as Vinpocetine. First used 22 years ago in Hungary as a treatment for senility and cerebrovascular disorders, this extract of the peri winkle plant is now FDA approved as a low cost dietary supplement.

It enhances circulation in the brain improves oxygen utilization, and provides direct protection against neurological damage caused by aging. A suggested dosage is two 5 mg tablets three times a day for the first 30 days, then one 5 mg tablet three times a day thereafter.

Herbal Supplements:

Two widely available herbal supplements have been shown to have anti-aging effects on the brain. Both are well tested and proven to be safe if used properly. 

• Ginkgo biloba is extremely effective in fighting brain aging. It's been used in China for thousands of years, and in Europe it's prescribed frequently by doctors to improve mental awareness and overall brian function.

The recommended daily dose of ginkgo biloba to improve brain function is 120-160 mg. Generally, you'll have to take it for at least six months before seeing results. 

• Ginseng is another effective herb for brain function. Its active ingredients are called glycosides, which work to improve your immune system and increase physical and mental energy. 

The recommended dose of ginsend is 500 to 600 mg of liquid extract, or 1 to 2 grams of dried root per day. 

It is recommended that you take ginseng daily for two ot three weeks, then take a break for two weeks before starting again. People with extremely high blood pressure are advised not to take ginseng.

You can use your mind power to help keep the rest of your body young and fit. It all boils down to attitude. If you think young and maintain a positive, youthful attitude, you can be young!

More and more older people are developing this attitude. You can see it in the numbers of active senior citizens. From exercise classes to jogging trails, you'll find active senior citizens everywhere, taking on the challenges and enjoying life long into their later years. 

And many keep working after "official" retirement, even if it's unpaid volunteer work. They've learned that acting and thinking young can actually keep you young. 

You can keep your mind positive by using positive imaging. Picture yourself young, vital and healthy. Know that you don't have to slow down. As long as you can see yourself staying active and young you can make it happen through your attitude.