Researchers: Time to clear up misconceptions about Alzheimer's

HERSHEY, Pa. -- The general perception of Alzheimer’s disease, including the dominant theory about what causes it, needs to shift, according to an editorial co-written by a Penn State College of Medicine faculty member. In “Changing Perspectives on Alzheimer’s Disease: Thinking Outside the Amyloid Box,” Penn State College of Medicine’s Daniel George said the common belief that scientists will soon conquer the disease is a misconception.

“What people commonly hear about Alzheimer’s disease is that a classic American success story is destined to unfold,” George said. “They hear that in the near future, biotechnology will soon conquer this scourge of the elderly, this stealer of decades that has become a growing global epidemic. Unfortunately, the scientific story is a bit more complicated.”

The editorial was published in the July issue of Journal of Alzheimer’s Disease.

The current dominant scientific theory as to the causation of Alzheimer’s disease assumes that toxic amyloid protein plaques in the brain are the causes of neuronal death. But George and fellow study author Simon D’Alton, University of Florida, say this theory is proving to be an unsustainable premise.

“There are many heavily age-related factors that affect the brain negatively and occur prior to the appearance of these so-called toxic plaques,” George explained. “What this means is that Alzheimer’s disease is not caused by one thing, like toxic proteins, but is multi-factorial and far more complicated than originally thought. We can’t continue to treat Alzheimer’s disease as if it were a singular condition, like a virus; this is not an honest portrayal.”

George said the reason for nearly 20 drug trial failures in the past decade is due to being trapped in the "amyloid box" -- trying to remove toxic proteins without addressing the real causes that precede them.

“This is like an oil company responding to a spill by having workers scrub petroleum off the shoreline rather than managing the upstream processes and procedures that could have slowed or prevented the spill and spread of oil,” he said. “We also don’t know what the role of amyloid is in the brain. There is much evidence to support amyloid actually being protective rather than just toxic.”

Since the processes leading to Alzheimer’s disease are not understood, it is unlikely that a profound therapy will be produced in the next 20 years, the scientists say. Instead, they say, a shift in approach that reflects the true nature of Alzheimer’s as a chronic, multifaceted, decades-long syndrome caused by gradual dysfunction of the aging body is needed. Many of these age-related changes can be greatly minimized by lifestyle changes that favor healthy diets, physical exercise, reduced exposure to toxins, lowered psychosocial stress, purposeful social interaction, and better protection from and treatment of traumatic brain injuries.

“Individuals need to know that they can increase their chances of maintaining a healthy brain as they age by taking these steps across their life course, and that help in the form of a pill or vaccine is unlikely to be realized in the near future,” George said. “Such an understanding can help people protect their aging brain and the brains of those they love and live amongst. Moreover, as we are all susceptible to aging processes, we should feel greater solidarity with those more severely affected by the changes of brain aging, who we can help in finding purpose, valued social roles and acceptance rather than the stigma, marginalization and fear fomented by the fading disease model.”

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Last Updated August 18, 2011