EH: How is this approach different from the way society currently addresses the challenges posed by Alzheimer's disease?

Dr. Lock: Too much research money has gone into finding a cure and looking for drugs to manage the disease. But this work has gleaned few benefits. A preventive approach is barely recognized at all, even by Alzheimer's disease advocacy groups.

EH: What sort of research should be conducted?

Dr. Lock: Alzheimer's disease is a heterogeneous and highly complex condition. It is very likely that certain people are to some extent more genetically predisposed to Alzheimer's disease regardless of their lifestyle choices. But to begin to understand what brings about neuroprotection, scientists and doctors must look much more closely at epidemiology and environment, and how such factors impact Alzheimer's disease risk. Neuroimaging shows that at least 30 percent of elderly people whose scans show the presence of neuritic plaques in the brain, do not show behavioral signs of dementia — even in the last years of their life. However, it's unclear what protects this population. It could be genetic or environmental — we don't yet know for sure.

EH: What did you find most surprising while researching and writing this book?

Dr. Lock: Many of the scientists I spoke with have difficulty entertaining new ways of thinking about this condition, even given the repeated failure of many hundreds of drug trial. Almost all of these trials were based on a similar model: to tackle plaques in the brain and remove them.

The amyloid cascade hypothesis, as it's known, was formulated in the early 1900s. Over the past decade, this hypothesis has been criticized. Even the scientist who proposed this theory is now skeptical. Today the Alzheimer's research field is in disarray, but some new explanations are starting to come about. One researcher argues, for example, that we must study massive neuronal networks in the brains of individuals to better understand the disease.

EH: Are we prepared for the growing Alzheimer’s population?

Dr. Lock: It depends on what you mean by “we.” I would argue that the Scandinavian countries, Japan, and possibly a few other places are reasonably well prepared. The United States is poorly prepared, though last year the Obama administration announced a well-funded effort to address the burdens of the disease. However, very little of this money is targeted for improved care and, above all, for support of family caregivers.

On the other hand, recent research from the UK and from Denmark shows that the incidences of Alzheimer's disease and other types of dementia have dropped. Individuals age 75 and older in these countries are less likely to develop Alzheimer's than individuals of the previous generation — possibly by as much as 25 percent.

EH: Are we doing enough research on prevention?

Dr. Lock: Currently, research on Alzheimer's disease prevention is focused on biomarker detection. This research is likely to fail. It will be very expensive and time-consuming. And if it does succeed, such genetic testing won't be made available to most people in the United States for a very long time.

Scientists need to start focusing on prevention. Preventive measures should be encouraged as part of a public health approach that takes place throughout one's life to protect both cardiac health and brain function. The majority of dementia cases are so-called "mixed dementias" — vascular dementia and Alzheimer's disease dementia at the same time. If one can prevent poor vascular health then they protect the heart — and the brain.

EH: Have the medical community and society lost sight of what “normal” aging is?

Dr. Lock: Only a few decades ago, menopause was treated like a disease — but scientists and doctors now understand it as a normal stage in a healthy woman's life. Even still, the medical community as a whole does not think about normal aging. This is not the way medicine is taught. Medicine and science focus on detection, diagnosis, and treatment of diseases. Prevention is seen as something deliverable through vaccine, not by how one lives their life each day. In other words, aging and Alzheimer's disease is heavily medicalized and treated entirely as a pathological problem.

Aging is approached as a disease-like condition, which in turn, has led the public to assume that the end of life — even the life of a healthy person — means descending into pathology and dementia. But on the other hand, medicalization of Alzheimer's disease has also helped to remove some of the stigma associated with this condition. We now can discuss these things in the open and care in a more kindly way for people with Alzheimer's disease.