Currently, most causes of dementia are not preventable. However, the National Institute on Aging (NIA) of the National Institutes of Health (NIH), along with various pharmaceutical companies, foundations, non-profit organizations and others, are all actively engaged in facilitating research and clinical trials aimed at slowing, delaying and preventing many forms of dementia—particularly Alzheimer’s disease (AD).

While there are no magic pharmacological bullets to prevent dementia, there’s lots of research that indicates that there are steps you can to take to reduce your risk for developing conditions leading to dementia, particularly Alzheimer’s disease.

What You Can do Now

We do know that it’s possible to reduce the risk of developing vascular dementia caused by a series of small strokes: If you smoke, quit. If you have high blood pressure and/or diabetes, talk with your doctor about how you can get those under control. Plus, many studies strongly suggest that eating a low-fat diet and exercising regularly may also reduce the risk of vascular dementia.

And remember, there are also some conditions that mimic dementia or have dementia-like symptoms (such as changes in blood sugar, sodium, and calcium and low vitamin B12 levels) that, if caught early enough may be treatable—which is one of many reasons why you shouldn’t delay getting diagnosed by a qualified medical professional.

Here’s the thing: In terms of preventing dementias (versus reducing the risk), we really don’t know anything for sure; but scientists all over the world are working on it. Currently, we know the most about Alzheimer’s disease. It’s the most common form of dementia, and the most studied. Thus, based upon these studies, consider the following:

Diet

There is some interesting evidence suggesting that eating a Mediterranean diet may decrease your risk of developing AD. A Mediterranean diet is one that includes relatively little red meat and emphasizes whole grains, fruits and vegetables, fish and shellfish, and nuts, olive oil and other healthy fats.

Other studies have examined foods rich in antioxidants and anti-inflammatory components to find out whether those foods affect age-related changes in the brain. For example, studies in rats and mice have shown that dietary supplementation with blueberries, strawberries, and cranberries can improve cognitive function, both during normal aging and in animals that have been bred to develop AD. And another study found that curcumin, the main ingredient of turmeric (the spice that gives American mustard its bright yellow color), can suppress the build-up of harmful amyloid plaques in the brains of rodents.

Mental Exercise

Studies have shown that keeping the brain active is associated with reduced AD risk. For example, in a rather famous long-term study called the Religious Orders Study, investigators periodically asked more than 700 participants—older nuns, priests, and religious brothers—to describe the amount of time they spent in seven information-processing activities. These activities included listening to the radio, reading newspapers, playing puzzle games, and going to museums.

After following the participants for four years, the investigators found that the risk of developing AD was 47 percent lower, on average, for those who did the activities most often than for those who did them least frequently. And, there are other studies that have found that those who have pursued higher levels of education appear to enjoy a protective effect for both cognitive (e.g., thinking, reasoning) and emotional outcomes.

Health experts believe that engaging in this level of mental exercise creates or contributes to your having a “cognitive reserve.” In other words, it’s not that this population isn’t just as prone to developing AD. But rather, they’ve developed additional neurons and pathways in their brains.

Think of it like this: If “normally” your brain has one road to transport information from point A to point B, and there’s a roadblock or dead end along the way, the information won’t make it to point B. However, people that have developed new ways of thinking about things have developed multiple and alternative routes in their brains to point B, as well as have developed additional destinations, overall.

So, you may want to seriously consider exercising your brain. Start doing crossword puzzles, learn how to do new things, like how to play bridge, dance, or anything that you’ve always wanted to learn how to do.

Social Engagement

There is some compelling research suggesting that seniors who spend most of their time in their immediate home environment are almost twice as likely to develop Alzheimer's disease compared to those who travel out of town. These findings, however, may also reflect the general health of the individual. So, this might be a chicken versus the egg phenomena.

Be that as it may, we do know that actively engaging in the world around you is good for one’s health – mentally, physically, and emotionally.

Aerobic Exercise

There are studies suggesting that when older adults with AD engage in aerobic exercise, it improves their psychological and behavioral symptoms. Note: In these studies, aerobic exercise was defined as repetitive and rhythmic movement of large muscle groups, such as the legs.

For example, investigators looked at the relationship of physical activity and AD risk in about 1,700 adults aged 65 years and older over a six year period. They found that the risk of AD was 35 to 40 percent lower in those who exercised for at least 15 minutes, three or more times a week than in those who exercised fewer than three times a week.

Smoking

There are studies suggesting that current smoking increases your risk of developing AD and other dementias —but having smoked in the past doesn’t appear to increase your risk. So, if you still smoke (and even if you’ve smoked for years), now is the time to quit. Talk with your doctor about ways of quitting that could work for you.

According to the National Institute of Neurological Disorders (NINDS), here are some other potentially preventive actions you may want to consider:

Lowering Cholesterol Levels

Research has suggested that people with high cholesterol levels have an increased risk of developing AD. Cholesterol is involved in formation of amyloid plaques in the brain. Mutations in a gene called CYP46 and the APOE e4 gene variant, both of which have been linked to an increased risk of AD, are also involved in cholesterol metabolism. Several studies have also found that the use of drugs called statins, which lower cholesterol levels, is associated with a lower likelihood of cognitive impairment.

Lowering Homocysteine

There’s a building block of protein that naturally circulates in the blood called homocysteine (an amino acid). Recent studies suggest that having higher than average blood levels of homocysteine is a risk factor for a number of neurodegenerative diseases, including Alzheimer's disease, vascular dementia, cognitive impairment, and stroke.

Eating foods high in folate (folic acid) and other B vitamins (such as B6 and B12) have been shown to successfully lower homocysteine levels in the blood. Whether or not increasing these B vitamins in one’s diet might offer a protective effect is yet unknown. That said, some good sources of natural folate include romaine lettuce, spinach, asparagus, broccoli, collard greens, parsley, cauliflower, beets, and lentils.

Lowering Blood Pressure

Several studies have shown that antihypertensive medicine reduces the odds of cognitive impairment in elderly people with high blood pressure. One large European study found a 55 percent lower risk of dementia in people over 60 who received drug treatment for hypertension. These people had a reduced risk of both AD and vascular dementia.

Controlling Inflammation

Many studies have suggested that inflammation may contribute to AD. Moreover, autopsies of people who died with AD have shown widespread inflammation in the brain that appeared to be caused by the accumulation of beta amyloid. Another study found that men with high levels of C-reactive protein, a general marker of inflammation, had a significantly increased risk of AD and other kinds of dementia.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Research indicates that long-term use of NSAIDs (such as ibuprofen, naproxen, and other similar drugs) may prevent or delay the onset of AD. Researchers are not sure how these drugs may protect against the disease, but some or all of the effect may be due to reduced inflammation. A 2003 study showed that these drugs also bind to amyloid plaques and may help to dissolve them and prevent formation of new plaques.