As many as 50 percent of Alzheimer’s cases worldwide could be avoided if risk factors such as depression, obesity and smoking were eliminated, either with lifestyle changes or treatment of underlying conditions. Even modest cuts in the level of risk factors could prevent millions of cases of the memory-robbing illness, the researchers said. As an example, a 25 percent cut in seven common risk factors – such as poor education, obesity and smoking — could prevent as many as three million Alzheimer’s cases around the world and up to half a million in the United States alone. The new research is being presented at the Alzheimer’s Association International Conference (AAIC) and published online in The Lancet Neurology.
“The idea here is to get a better bead on exactly how we can start untangling what the risk factors are, so that we can not only treat and modify Alzheimer’s but also start talking about prevention of Alzheimer’s,” said Mark Mapstone, associate professor of neurology at the University of Rochester Medical Center. “The field is working very hard (to figure out) what these risk factors are so we can start heading this disease off before it starts.”
Led by Deborah Barnes of the University of California San Francisco (UCSF), the researchers revisited earlier epidemiological studies on links between Alzheimer’s and seven vital risk factors: poor education, smoking, low physical activity, depression, hypertension during mid-life, obesity and diabetes. They estimated that these risk factors account for 17 million cases of Alzheimer’s worldwide (approximately half of the estimated 34 million cases of dementia globally) and three million of the 5.3 million estimated cases in the United States. Some factors appeared to have a greater impact on Alzheimer’s risk than others. The UCSF team estimated that worldwide, 19 percent of Alzheimer’s cases can be attributed to low education; 14 percent to smoking; 13 percent to physical inactivity; 10 percent to depression; five percent to mid-life hypertension; 2.4 percent to diabetes; and two percent to obesity. In the United States, more than 20 percent of cases can be traced to low physical activity; 15 percent to depression; 11 percent to smoking; eight percent to mid-life hypertension; seven percent to mid-life obesity; seven percent to low education and three percent to diabetes.
Dr. Ronald Petersen of the Mayo Clinic said the findings have important public-health implications and will help raise awareness of the need for prevention. The study offers “an uplifting message for aging and cognition,” he said, insofar as it suggests that lifestyle factors can be modified to alter Alzheimer’s risk, at least at the societal level. But, with the exception of increasing physical activity, there is scant evidence that interventions are successful in altering an individual’s chances of developing Alzheimer’s.
Other studies have shown that increasing physical activity is effective. But whether taking up crossword puzzles or losing weight impacts the path of Alzheimer’s — the pathology of which seems to begin years before symptoms appear — remains unknown. Last year, a National Institutes of Health panel concluded – with some controversy — that the scientific evidence on lifestyle factors was negligible and said that intervention is helpful. Petersen said that, while depression is clearly associated with Alzheimer’s, the causal direction could go either way, especially when the depression comes late in life. “Is that really a risk factor for, or a function of, the disease?” he asked. The question is, for the most part, irrelevant from a clinical perspective because depression should be treated anyway, Petersen said.
“Education, even at a young age, starts to build your neural networks,” so being deprived of it means poorer brain development, Barnes said.
“It gives us a little bit of hope about things we could do now about the epidemic that is coming our way.” Alzheimer’s cases are expected to triple by 2050, to approximately 106 million globally. “What’s exciting is that this suggests that some very simple lifestyle changes, such as increasing physical activity and quitting smoking, could have a tremendous impact on preventing Alzheimer’s and other dementias in the United States and worldwide,” Dr Barnes said.
The study could be good news for people – usually family members – who are caregivers for individuals with Alzheimer’s. “Throughout the progression, I felt quite helpless…without any cure for (Alzheimer’s disease) yet, I could only watch,” said Rick Lauber, who acted as caregiver to his father, John, who developed the disease in his 60s and died at age 76. As his father’s caregiver, Lauber had to take on unexpected responsibilities, such as moving him three times, taking him to doctor’s appointments, paying bills and becoming his father’s Joint Guardian and Alternate Trustee. “As an adult child and a family caregiver, caring for Dad had to one of the hardest things imaginable,” Rick Lauber said. “Watching him decline from a healthy, active, respected academic to a shell of a man was very challenging. Dad was changing before my eyes and I could not do anything about this.”
According to the 2011 annual Facts and Figures release from the Alzheimer’s Association, nearly 15 million Americans provide 17 billion hours of unpaid care worth $202 billion every year.
This blog is dedicated to the memory of William A. Alter, the founder of our company who passed away August 8, 2008 of complications of Alzheimer’s disease. To read about Bill Alter’s amazing career, please click here.