Alzheimer’s Facts and Statistics

Alzheimer’s disease is a brain disorder named for German physician Alois Alzheimer, who first described it in 1906. Scientists have learned a great deal about Alzheimer’s disease in the century since Dr. Alzheimer first drew attention to it. Today we know that Alzheimer’s:

•Is a progressive and fatal brain disease. Up to 5 million Americans now have Alzheimer’s disease. Alzheimer’s destroys brain cells, causing problems with memory, thinking and behavior severe enough to affect work, lifelong hobbies or social life. Alzheimer’s gets worse over time, and it is fatal. Today it is the seventh-leading cause of death in the United States.

•Is the most common form of dementia, a general term for the loss of memory and other intellectual abilities serious enough to interfere with daily life. Vascular dementia, another common type of dementia, is caused by reduced blood flow to parts of the brain. In mixed dementia, Alzheimer’s and vascular dementia occur together.

•Has no current cure. But treatments for symptoms, combined with the right services and support, can make life better for the millions of Americans living with Alzheimer’s. We’ve learned most of what we know about Alzheimer’s in the last 15 years. There is an accelerating worldwide effort under way to find better ways to treat the disease, delay its onset, or prevent it from developing.

Alzheimer’s and the brain

Just like the rest of our bodies, our brains change as we age. Most of us notice some slowed thinking and occasional problems remembering certain things. However, serious memory loss, confusion and other major changes in the way our minds work are not a normal part of aging. They may be a sign that brain cells are failing.

The brain has 100 billion nerve cells (neurons). Each nerve cell communicates with many others to form networks. Nerve cell networks have special jobs. Some are involved in thinking, learning and remembering. Others help us see, hear and smell. Still others tell our muscles when to move.

To do their work, brain cells operate like tiny factories. They take in supplies, generate energy, construct equipment and get rid of waste. Cells also process and store information. Keeping everything running requires coordination as well as large amounts of fuel and oxygen.

In Alzheimer’s disease, parts of the cell’s factory stop running well. Scientists are not sure exactly where the trouble starts. But just like a real factory, backups and breakdowns in one system cause problems in other areas. As damage spreads, cells lose their ability to do their jobs well. Eventually, they die.

Causes and risk factors

While scientists know that Alzheimer’s disease involves the failure of nerve cells, why this happens is still not known. However, they have identified certain risk factors that increase the likelihood of developing Alzheimer’s:

Age

The greatest known risk factor for Alzheimer’s is increasing age. Most individuals with the illness are 65 and older. The likelihood of developing Alzheimer’s approximately doubles every five years after age 65. After age 85, the risk reaches nearly 50 percent.

Family history and genetics

Another risk factor is family history. Research has shown that those who have a parent, brother or sister with Alzheimer’s are two to three times more likely to develop the disease. The risk increases if more than one family member has the illness. Scientists have so far identified one gene that increases the risk of Alzheimer’s but does not guarantee an individual will develop the disorder. Research has also revealed certain rare genes that virtually guarantee an individual will develop Alzheimer’s. The genes that directly cause the disease have been found in only a few hundred extended families worldwide and account for less than 5 percent of cases. Experts believe the vast majority of cases are caused by a complex combination of genetic and non-genetic influences.

Other risk factors

Age, family history and genetics are all risk factors we can’t change. Now, research is beginning to reveal clues about other risk factors that we may be able to influence. There appears to be a strong link between serious head injury and future risk of Alzheimer’s.

It’s important to protect your head by buckling your seat belt, wearing your helmet when participating in sports and “fall-proofing” your home.

One promising line of research suggests that strategies for overall healthy aging may help keep the brain healthy and may even offer some protection against Alzheimer’s. These measures include eating a healthy diet; staying socially active; avoiding tobacco and excess alcohol; and exercising both body and mind.

Some of the strongest evidence links brain health to heart health. The risk of developing Alzheimer’s or vascular dementia appears to be increased by many conditions that damage the heart and blood vessels. These include heart disease; diabetes; stroke and high blood pressure; or high cholesterol. Work with your doctor to monitor your heart health and treat any problems that arise.

Studies of donated brain tissue provide additional evidence for the heart-head connection. These studies suggest that plaques and tangles are more likely to cause Alzheimer symptoms if strokes or damage to the brain’s blood vessels are also present.

Above content provided by The Alzheimer’s Association in partnership with Beth Israel Deaconess Medical Center.

For advice about your medical care, consult your doctor.