Can Alzheimer Disease be Prevented?

A highlight of the Alzheimer’s Association International Conference 2011 (AAIC), held in Paris this past July, was a presentation by researchers using a new mathematical model of global Alzheimer’s risk suggesting that reducing the prevalence of well-known, lifestyle-based, chronic disease risk factors by 25 percent could potentially prevent 3 million cases of Alzheimer’s worldwide, including nearly one half million in the U.S.

To put that in perspective, it is estimated that over 5.4 million in the U.S. (110,000 in Washington State) and 36 million worldwide have Alzheimer’s disease. It is also anticipated that without a cure or a therapy to stop the disease’s progression (which we currently don’t have), these numbers will triple by 2050.If your risk of developing Alzheimer’s could belowered and influenced by lifestyle changes, wouldn’t you want to implement those changes?

What is Alzheimer’s disease? Is it different from dementia?

Alzheimer's is a type of dementia that causes problems with memory, thinking and behavior. Symptoms usually develop slowly and get worse over time, becoming severe enough to interfere with daily tasks. Alzheimer's is the most common form of dementia, a general term for memory loss and other intellectual abilities serious enough to interfere with daily life. Alzheimer's disease accounts for 50 to 80 percent of dementia cases.

Alzheimer's is not a normal part of aging, although the greatest known risk factor is increasing age, and the majority of people with Alzheimer's are 65 and older. But Alzheimer's is not just a disease of old age. Up to 5 percent of people with the disease have younger-onset Alzheimer's, which often appears when someone is in their 40s or 50s.

Alzheimer's is not the only cause of memory loss. Many people have trouble with memory — this does NOT mean they have Alzheimer's. There are many different causes of memory loss. If you or a loved one is experiencing symptoms of dementia, it is best to visit a doctor so the cause can be determined.

Model Shows Lowering Risk Factors May Prevent Millions of Alzheimer's Cases

At AAIC 2011, researchers reported the proportion of Alzheimer's cases in the U.S. that are potentially attributable to each of the seven risk factors:

• physical inactivity 21 percent
• depression 15 percent
• smoking 11 percent
• mid-life hypertension 8 percent
• mid-life obesity 7 percent
• low education 7 percent
• diabetes 3 percent

Together, the seven potentially modifiable risk factors contributed to roughly 50 percent of Alzheimer's cases in the U.S. (54 percent, 2.9 million).

"We were surprised that lifestyle factors such as physical inactivity and smoking appear to contribute to a larger number of Alzheimer's cases than cardiovascular diseases in our model," said Deborah Barnes, PhD, MPH, from UC, San Francisco and Mental Health Research PI at the San Francisco Veterans Affairs Medical Center. "But this suggests that relatively simple lifestyle changes such as increasing physical activity and quitting smoking could have a dramatic impact on the number of Alzheimer's cases over time."

Can Alzheimer's be prevented?

It's a question that continues to intrigue researchers and fuel new investigations. There are no clear cut answers yet — partially due to the need for more large-scale studies — but promising research is under way. The Alzheimer's Association continues to fund studies exploring the influence of mental fitness, physical fitness, diet and environment. As the number of people affected by Alzheimer's rises, the effort to find prevention strategies continues to gain momentum.

Dr. Jack C. de la Torre, a prominent Alzheimer's researcher at the National Institutes of Health-funded Banner Sun Health Research Institute in Arizona, believes, as do thousands of other Alzheimer's researchers, "The same strategy we use against other chronic diseases of aging, such as heart disease,can cut our risk of Alzheimer's.”

Heart-Head Connection

The risk of developing Alzheimer's or vascular dementia appears to increase as a result of many conditions that damage the heart or blood vessels. These include high blood pressure, heart disease, stroke, diabetes and high cholesterol. Some autopsy studies show that as many as 80 percent of individuals with Alzheimer's disease also have cardiovascular disease.

High cholesterol, blood pressure, high blood sugar, insulin resistance, diabetes, obesity and physical inactivity - lifestyle factors that cause heart attacks and strokes - researchers tie to Alzheimer's. "Taking care of your heart protects your brain," says De la Torre. He urges preventing Alzheimer's by screening for and treating cardiovascular disease in middle age, years before signs of memory loss and dementia appear.

Dr. Laura Baker, an Assistant Professor of Psychiatry and Behavioral Sciences at The University of Washington Medical Center in Seattleand researcherwith the UW/VA Memory Wellness Program, suggests, “One strategy is to take proactive steps to optimize physical health. What happens below the neck will most certainly affect what goes on above the neck! Physical conditions such as heart disease, type 2 diabetes, pulmonary disease, as well as kidney or liver disease can compromise brain function and thus impact cognitive health.

In the interest of prevention, request fasting blood tests to measure cholesterol, glucose, insulin, thyroid function, liver function, and kidney function, as well as vitamin levels of B and D. Keep a careful record of blood pressure, maintain a healthy diet, and exercise! It is also important to monitor stress and mood, as these factors can also have negative consequences for memory and thinking abilities.”

What Can You Do?

When people think about staying fit, they generally think from the neck down. But the health of your brain plays a critical role in almost everything you do: thinking, feeling, remembering, working, playing — and even sleeping.

Exercise is good for body and mind

Stay physically active. Physical exercise is essential for maintaining good blood flow to the brain as well as to encourage new brain cells. It also can significantly reduce the risk of heart attack, stroke and diabetes, and thereby protect against those risk factors for Alzheimer's and other dementias.

Growing evidence shows that physical exercise does not have to be strenuous or even require a major time commitment. It is most effective when done regularly, and in combination with a brain-healthy diet, mental activity and social interaction.

Aerobic exercise improves oxygen consumption, which benefits brain function; aerobic fitness has been found to reduce brain cell loss in elderly subjects. Walking, bicycling, gardening, tai chi, yoga and other activities of about 30 minutes daily get the body moving and the heart pumping.

A healthy diet is a must

Adopt a healthy diet. According to the most current research, a brain-healthy diet is one that reduces the risk of heart disease and diabetes, encourages good blood flow to the brain, and is low in fat and cholesterol. Like the heart, the brain needs the right balance of nutrients, including protein and sugar, to function well. A brain-healthy diet is most effective when combined with physical and mental activity and social interaction.

Manage your body weight for overall good health of brain and body. A long-term study of 1,500 adults found that those who were obese in middle age were twice as likely to develop dementia in later life. Those who also had high cholesterol and high blood pressure had six times the risk of dementia. Adopt an overall food lifestyle, rather than a short-term diet, and eat in moderation.

Increase your intake of protective foods. Current research suggests that certain foods may reduce the risk of heart disease and stroke, and appear to protect brain cells. In general, dark-skinned fruits and vegetables have the highest levels of naturally occurring antioxidant levels.

Cold water fish contain beneficial omega-3 fatty acids: halibut, mackerel, salmon, trout and tuna.

Some nuts can be a useful part of your diet; almonds, pecans and walnuts are a good source of vitamin E, an antioxidant.

Remain socially active. Social activity not only makes physical and mental activity more enjoyable, it can reduce stress levels, which helps maintain healthy connections among brain cells

Research shows that people who are regularly engaged in social interaction maintain their brain vitality. But again, the combination of physical and mental activity with social engagement — and a brain-healthy diet — is more effective than any of these factors alone.

One study reported that leisure activities that combine physical, mental and social activity are the most likely to prevent dementia. In the study of 800 men and women aged 75 and older, those who were more physically active, more mentally active or more socially engaged had a lower risk for developing dementia. And those who combined these activities did even better.

Other research found that sports, cultural activities, emotional support and close personal relationships together appear to have a protective effect against dementia.

Stay mentally active. Mentally stimulating activities strengthen brain cells and the connections between them, and may even create new nerve cells.

Mental decline as you age appears to be largely due to altered connections among brain cells. But research has found that keeping the brain active seems to increase its vitality and may build its reserves of brain cells and connections. You could even generate new brain cells.

Low levels of education have been found to be related to a higher risk of Alzheimer’s later in life. This may be due to a lower level of life-long mental stimulation. Put another way, higher levels of education appear to be somewhat protective against Alzheimer’s, possibly because brain cells and their connections are stronger. Well-educated individuals can still get Alzheimer’s, but symptoms may appear later because of this protective effect.

You don’t have to turn your life upside down, or make extreme changes to achieve many of these benefits. Start with something small, like a daily walk. After a while, add another small change.

The good news is that emerging evidence suggests these steps can help keep your brain healthier as you age. These steps might also reduce your risk of Alzheimer’s disease or other dementias. Like other parts of your body, your brain may lose some agility as you get older. It can deteriorate even more if you don’t take care of it. Science is unlocking many of the mysteries of the brain, but we don’t have all the answers yet. You can do everything “right” and still not prevent Alzheimer’s disease. What’s offered here is the best and most up-to-date information available so you can make your own decisions about your health.

About the Alzheimer's Association

The Alzheimer's Association is the world's leading voluntary health organization in Alzheimer's care, support and research.Our mission is to eliminate Alzheimer's disease through the advancement of research, to provide and enhance care and support for all affected, and to reduce the risk of dementia through the promotion of brain health. Our vision is a world without Alzheimer's. The Western and Central Washington State Chapter, based in Seattle, serves a 23-county region. Visit www.alzwa.org or call 206.363.5500 for more information.