For the first time in history, non-infectious chronic diseases (cancer, heart disease, diabetes and dementia) have replaced infectious diseases in the majority of deaths worldwide.
In the U.S., Alzheimer’s disease (AD) is second only to cancer as the most feared diagnosis. Alzheimer’s is a cruel disease; symptoms progress over a decade, slowly and relentlessly robbing people of their memories, ability to think, and remain independent. No one has ever survived Alzheimer’s disease and the current available treatments have very modest benefits. Sixteen million American caregiving families and friends last year accounted for $232 billion in free care during 18.4 billion hours.
The greatest risk factor for developing AD is age. AD affects 10 percent of people over 65 years, and 45 percent over 85 years. Nearly 50 million people worldwide have AD, and this number is expected to nearly triple over the next 30 years, due to the world’s aging population.
Sobering news, but there is hope.
Through current brain imaging capabilities and blood and spinal fluid testing, we know that AD typically starts ‘silently’ in midlife with the slow accumulation of two proteins — amyloid and tau— decades before the mildest symptoms appear. Disease gradually progresses to subtle memory problems and then worsens to involve additional thinking skill (reasoning, judgment, attention, and language). When these symptoms reduce a person’s ability to perform everyday activities, a diagnosis of Alzheimer’s “dementia” is made. Patients with AD often have a second form of dementia (vascular, Lewy body, etc.).
Treatment – medical and practical
What about treatment? First, there are non- modifiable risk factors, such as advancing age and genetic risk factors, such as a protein called ApoE4. About one-fourth of the population carries this protein, and people with one or two copies of ApoE4 have a threefold and twelvefold, respectively, increased risk of AD. Gene therapy advances may make it possible to either “silence” or alter ApoE4.
Modifiable risk factors include cardiovascular disease (e.g., diabetes, high blood pressure, heart disease) and social and cognitive disengagement. A healthy heart helps to maintain a healthy brain, and an active mind increases resilience to AD. Eating a healthy diet, avoiding mid-life weight gain, not smoking, modestly drinking alcohol, regularly exercising (even walking!), treating diabetes, high cholesterol and high blood pressure if diagnosed, maintaining strong social ties with your friends and family (don’t be too busy to visit, call, or e-mail), and keeping mentally active (reading, seeking challenging mental tasks, being the ‘eternal student’!) could reduce the cases of Alzheimer’s disease worldwide by as much as a third! The Alzheimer’s Association is a great first resource for those interested in learning more: https://www.alz.org.
On the scientific front, there are many clinical trials to reduce levels of abnormal amyloid and tau proteins, as well as trials focusing on the brain’s immune system, neurotransmitters, and improving brain cell survival. Gene therapies and adult stem cell approaches will likely impact the future course of AD.
MARTIN M. BEDNAR, M.D., PH.D. is vice president, Neuroscience Therapeutic Area Unit, Takeda Pharmaceuticals and a fellow of the American Association of Neurological Surgeons. Throughout his pharmaceutical career, he has focused on Alzheimer’s disease therapies. Dr. Bednar is president of the Providence, RI Legatus chapter and a frequent author on the interrelationship of science and religion, embracing the sanctity of life from conception to natural death.