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Alzheimer’s Disease

Alzheimer’s Disease

(Bloomberg) -- Humans are getting better at delaying death. Globally, people on average live to 72, more than five years longer than in 2000. What we haven’t yet figured out is how to beat one of the worst afflictions of aging: Alzheimer’s disease. The brain-shrinking progressive illness has emerged as one of the planet’s biggest public health challenges. More than a century after the tell-tale signs of Alzheimer’s were first seen under a microscope, a few drugs treat the disease’s symptoms, but there are still none that slow, let alone reverse, its progression. Researchers estimate there are 50 million people worldwide living with dementia, with Alzheimer’s the cause in up to 70% of cases. Aging populations mean the number is expected to almost double every 20 years in the absence of medical breakthroughs on preventions or cures. 

The Situation

Drug companies working to combat the underlying disease have long targeted the protein amyloid, which clumps in the brain of Alzheimer’s patients. Researchers don’t know whether amyloid triggers Alzheimer’s or is a minor contributor. Multiple trials of drugs targeting the protein have proved disappointing. The U.S. biotechnology company Biogen Inc. in late 2019 revived one such experimental treatment, after earlier stopping two studies of the medicine based on poor results. The company said additional data showed the infusion, if given for long enough and at high doses, could offer some benefit. Meanwhile, interest has grown in new approaches, especially in those focused on an aberrant protein called tau. As Alzheimer’s progresses, tau spreads through the brain, accumulating in tangles that strangle brain cells. Among the companies testing tau strategies are Eli Lilly, Johnson & Johnson, Biogen, AbbVie and TauRx Pharmaceuticals. The economic costs of dementia care were estimated at $948 billion in 2016, or about 1.2% of the globe’s economic output.

Alzheimer’s Disease

The Background

German psychiatrist Alois Alzheimer was the first to connect dementia to abnormal protein deposits in brain tissue, in 1906. Research into the symptoms, causes, risk factors and treatment of the disease later named for him has taken place mostly in the last 30 years, and the precise chemistry remains largely unknown. Typically, symptoms first appear when Alzheimer’s patients are in their mid-60s. Until recent years, the only way doctors could be certain patients had Alzheimer’s disease was to check their brain tissue under a microscope for amyloid deposits, or plaques. The exam wasn’t especially helpful because the patient was already dead. A breakthrough came in 2012, when the U.S. Food and Drug Administration approved a dye used in scans to detect the plaques. For the first time, live people could be reliably diagnosed. The scans enabled doctors to track growth of the deposits to the progression of dementia. They also led to the observation that plaques emerge in some relatives of patients almost two decades before the typical onset of the disease. The scans meant people with other forms of dementia could be excluded from Alzheimer’s drug trials, producing more reliable results, and plaques could be used to measure the efficacy of treatments.

Alzheimer’s Disease

The Argument

Lacking a cure, the governments of more than 30 countries and territories have set forth a jumble of dementia-fighting plans. They include commitments to pay more for research, build residential care centers, increase awareness of palliative measures and draw up ethical guidelines for caregivers. France was the first in Europe, in 2001. The U.S. released its version in 2012. Alzheimer’s advocates are in a contest for resources against groups representing heart disease, cancer and other maladies that kill many more people. Financial challenges overlap with cultural ones. In China, in accordance with the Confucian value of parental devotion, most patients are cared for at home, often putting stress on their families. In Japan, there is fear that the limits of the welfare system will conflict with an obligation to care for the elderly. A rape prosecution in the U.S. against the husband of a woman with Alzheimer’s raised disquieting questions about sexual consent. Studies reporting behavioral improvement from treatment with turmeric and green tea vex skeptics of dietary nostrums. Stigma is a concern. In a global survey taken in 2019, 24% of patients in high-income countries said they’d make an effort to keep their dementia a secret.

The Reference Shelf

  • The World Health Organization lists 10 facts that show the magnitude of the global dementia challenge.
  • The National Institute on Aging aggregates information on Alzheimer’s disease, its symptoms, diagnosis and treatment.
  • Alzheimer’s Disease International examines the issue of stigma in its World Alzheimer Report 2019.
  • Alzforum is a web-based scientific community dedicated to understanding Alzheimer’s disease and related disorders.

Jason Gale contributed to the original version of this article.

To contact the editor responsible for this QuickTake: Lisa Beyer at lbeyer3@bloomberg.net

©2019 Bloomberg L.P.