Alzheimer's disease might well be considered an epidemic in our country. With more than 5.3 million Americans diagnosed with the disease and that number expected to double by 2030, it makes sense to ask ourselves what can be done to prevent this devastating disease. According to a recent Medscape report, the costs associated with Alzheimer's disease globally are staggering at an estimated $604 billion, or a full one percent of the world's gross domestic product.
But looking beyond the economic impact, the emotional costs borne by the families of Alzheimer's patients is incalculable -- and I speak from personal experience.
Alzheimer's is a disease for which there is no effective treatment whatsoever. To be clear, there is no pharmaceutical agent, no magic pill that a doctor can prescribe that will have any significant effect on the progressive downhill course of this disease.
But can it be prevented? A recent article appearing in the The New York Times entitled, "Years Later, No Magic Bullet Against Alzheimer's Disease" clearly led readers to believe that nothing a person could do could change the course of destiny if Alzheimer's was in the cards. The report summarized the findings of a 15-member group of scientists who spent a full day and a half reviewing the medical literature after which they concluded that any retrospective studies evaluating Alzheimer's disease risk were not up to the gold standard of scientific testing. That is to say that they basically concluded that the extensive body of research that looked back in time to determine who would and who wouldn't get the disease were simply not good enough to meet their standards. The only tests the group considered valid were so-called double-blind placebo-controlled studies in which one group gets a treatment moving forward while another gets a placebo. After a period of time, the two groups are compared and conclusions are then drawn as to the effectiveness of the treatment. This type of study obviously works great if you are testing a drug which could generate revenue, while it is hard to imagine anyone sponsoring this type of study for a lifestyle change like exercise or dietary modification which, if proven effective, wouldn't translate into blockbuster sales.
But retrospective studies have long been deemed fully acceptable for health related recommendations. Take for instance the recommendation that people should wear seat belts in the car. This well-founded recommendation is based on the studies that looked back and revealed that a person's risk of serious injury in a car accident was much reduced if that person had been wearing a seat belt. Obviously, we wouldn't need to do a double-blinded study to prove this point, or ever even consider doing so. The point is, retrospective studies are powerful and meaningful.
That said, the most well respected peer-reviewed medical journals dealing with Alzheimer's disease have long published reports that have demonstrated in great detail who is at risk for the disease. For example, at the 2006 meeting of the American Academy of Neurology, Dr. Rachel Whitmer, a research scientist at Kaiser Permanente of Northern California, showed that individuals with high amounts of body fat had a risk of Alzheimer's increased by 293 percent compared to low body fat when followed up to 27 years after their initial evaluation. Another study following 1200 people from 1986 until 2006 found that those who exercised regularly saw a decreased risk for developing Alzheimer's disease by about 40 percent. This study joins countless others relating exercise to reduced risk for the disease and is bolstered by the report just last month showing actual increase in size of the brain's most important memory structure, the hippocampus, induced by aerobic exercise. This is critically important as this is the area of the brain that first degenerates in Alzheimer's disease. As the authors stated,
Exercise training increased hippocampal volume by two percent, effectively reversing age-related loss in volume by one to two years.
Homocysteine is an amino acid compound that is toxic to the brain much as cholesterol damages the coronary arteries. But unlike the drugs used to lower cholesterol, homocysteine is lowered to normal levels with nonprescription B vitamins. Research has shown that even mild elevations of homocysteine have a dramatic role in increasing Alzheimer's risk. A level of just 14 was associated with doubling of the risk for the disease as described in the prestigious New England Journal of Medicine, and reviewed in a National Institutes of Health press release stating,
People with elevated levels of homocysteine in the blood had nearly double the risk of developing Alzheimer's disease, according to a new report from scientists at Boston University. The findings, in a group of people participating in the long-running Framingham Study, are the first to tie homocysteine levels measured several years before with later diagnosis of AD and other dementias.
Other studies looking back to determine risk have overwhelmingly demonstrated the protective effects of higher education, engagement in leisure activities and higher levels of the omega-3 fatty acid, DHA.
The bottom line is that this author, a practicing neurologist dealing with Alzheimer's disease on a daily basis, believes we need to expand the public awareness that modifiable lifestyle factors have a profound role to play in determining who will or won't get this disease. For now, we are being told to pretty much live our lives, come what may and hope for a pharmaceutical magic bullet. But the science tells us otherwise, and gives us hope that we can indeed take action today to reduce our risk for Alzheimer's disease.