Dementia is a brain disorder in which the abilities to think, remember and perform the common activities of life are diminished. It is estimated that dementia affects more than 25 million people in the world today. This number is expected to double by 2020 and double again by 2040. We are at the threshold of an epidemic.
Dementia and Alzheimer’s disease are often thought of as one and the same thing. However, while Alzheimer’s is the most common form of dementia, it accounts for only about 45 percent of dementia cases. Another 30 percent of dementia cases are caused by stroke, hardening of the arteries or other forms of decreases in blood flow to the brain that are collectively known as vascular dementia. About 10 percent of cases are caused by Lewy body dementia, which is a condition related to Parkinson’s disease, and another 10 percent by frontotemporal dementia. The remaining cases are due to rarer forms of brain disease. Because Alzheimer’s is the most thoroughly studied form of dementia and the type of dementia that I am most frequently asked about, I will limit my discussion to it. However, much of what I will discuss holds true for the other forms as well.
Many people think that dementia is an unavoidable part of growing old. But this is not the case. Counter-examples abound. Michael DeBakey, the pioneer heart surgeon, continued to practice medicine well into his 90s. The architect Frank Lloyd Wright completed his last design at the age of 92. The American folk artist Anna Mary Robertson, better known as Grandma Moses, painted some of her best-loved works beyond the age of 100 years. Perhaps most remarkable was Michel-Eugene Chevreul, the father of gerontology. Dr. Chevreul began his seminal studies of aging when he was in his 90s. He published his last scientific paper at the age of 102.
What many people, even doctors, don’t realize is that there are two basic types of Alzheimer’s disease. One is early-onset, or familial Alzheimer’s, and the other is late-onset, or sporadic Alzheimer’s. Familial Alzheimer’s disease is very strongly influenced by genetics, and manifests at an early age. Auguste Deter was the first patient in whom Dr. Alois Alzheimer described symptoms of the disease that now bears his name. She was only 51 years old in 1901 when the severity of her condition forced her husband to seek help for her. She deteriorated very rapidly and died in an asylum at the age of 55. There are two well-described genetic forms of early-onset Alzheimer’s and inheriting those faulty genes almost guarantees the development of severe illness at an early age. Fortunately, these familial forms of Alzheimer’s account for only 5 percent of cases.
The most common form of Alzheimer’s dementia, the so-called sporadic type, begins later in life. It usually first appears after the age of 65, and progresses rather slowly. It is called sporadic because it can pop up in families where it has not previously been seen.
Genetics can contribute to this late-onset form of Alzheimer’s. This most often involves inheritance of the APOe 4 gene. APOe is a housekeeping gene that comes in several genetically determined varieties. Having the APOe 4 type increases the risk of developing Alzheimer’s disease, usually in one’s late 60s or early 70s. However, unlike the early-onset Alzheimer’s genes, mere possession of the APOe 4 gene does not entail that one will develop Alzheimer’s. In fact, it appears that having this form of the gene only exacerbates the effects of other risk factors for Alzheimer’s, such as poor diet, high blood pressure, stress, high cholesterol, diabetes and other health problems.
If lifestyle factors that increase the risk of Alzheimer’s are controlled, it is entirely possible to avoid Alzheimer’s disease, even while carrying the APOe4 gene.
Even the prudently conservative National Institutes of Health now recognizes steps that can be taken to reduce the risk of Alzheimer’s. Among the institute’s recommendations are staying physically and intellectually active throughout life, maintaining normal blood sugar, maintaining healthy weight, eating a healthy diet such as the Mediterranean diet and controlling blood pressure. Other good health measures that can be taken to reduce the risk of Alzheimer’s include reducing stress, treating depression, maintaining friendships, finding spiritual meaning in life, diagnosing and treating sleep apnea and regular visits to the dentist. There is also increasing evidence that various herbs, vitamins and mineral supplements can help keep the aging brain healthy and vibrant.
A number of available books explain how lifestyle changes can help reduce the risk of Alzheimer’s. Of course, I recommend my own book, “Beyond Alzheimer’s: How to Avoid the Modern Epidemic of Dementia.” Other excellent books have been written by Drs. Gary Small, Vincent Fortanasce, Marwan Sabbagh and P. Murali Doraiswamy. These books, like mine, reinforce the growing awareness that in most people Alzheimer’s can be prevented or at least delayed.
A caveat is necessary. Although late-onset Alzheimer’s usually does not manifest until a person is in his mid-60s or 70s, the pathological changes in brain tissue that eventually result in dementia may begin at least 15 years before the changes in memory and thinking first appear. If you want to prevent, or at least slow, the course of Alzheimer’s, you had better start now.
Scott D. Mendelson of Roseburg is lead psychiatrist at the Veterans Affairs Roseburg Healthcare System. He has published numerous research papers and several books in the areas of psychiatry and neuroscience. Submit questions and comments to firstname.lastname@example.org. Questions cannot be answered directly, but may serve as subject matter for future columns.