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Alzheimer’s Disease appears in three distinct subtypes, according to a study published this week.

The discovery could fundamentally change the way that the disease is understood, treated – and eventually cured, said the University of California at Los Angeles scientist behind it.

“Because the presentation varies from person to person, there has been suspicion for years that Alzheimer’s represents more than one illness,” said Dale Bredesen, a professor of neurology at the school who authored the study, which appears this week in the journal Aging.

The three types vary widely – and present a biochemical way of looking at the disease, the scientists said. The inflammatory variety of the disease shows markers such as C-reactive protein, and serum albumin to globulin ratios, are increased. The non-inflammatory kind doesn’t show those kind of biomarkers increasing – but is indicated by other metabolic abnormalities, they found. The third subtype is the cortical, which is seen in relatively young people – and spreads more widely across the brain than the other kind.

The cortical kind is different in that it is often misdiagnosed, and language skills are lost at first, with only memory loss coming later. This variety also affects people who do not have an Alzheimer’s gene – and is connected to a significant zinc deficiency, they added.

The two-year study was the result of metabolic testing of 50 people. The cases highlighted in the study showed the wide spectrum of how the disease appears differently in common lives. A 65-year-old man with superior memory his whole life started experiencing “senior moments” that became more and more common over a four-year period, due to the inflammatory variety of the disease. A 75-year-old woman had progressive memory loss over just one year – the same age her mother did – due to the non-inflammatory kind. And a 52-year-old scientist had two years of cognitive decline which started with difficulty with simple mathematics and ended with a “simple, childlike affect” due to the cortical subtype.

“The important implications of this are that the optimal treatment may be different for each group, there may be different causes, and, for future clinical trials, it may be helpful to study specific groups separately,” Bredesen added.

Other brain experts have proposed that Alzheimer’s manifests in different varieties – including early- and late- onset, and genetically-tied forms of the disease. But Bredesen’s connections between biochemistry and the different subtypes appear to be unique.

Research into the brain disease has not produced breakthroughs this year. In July, the Alzheimer’s Association International Conference was held in Washington, D.C. But one of the bigger announcements was re-proposing a drug which had proven ineffective in beating the disease in the past. At the same conference, it was estimated that 28 million Baby Boomers would have the disease by the year 2050.

Bredesen, who focuses on the metabolic functions associated with the disease, published a paper last year showing that lifestyle, exercise and diet changes improve cognition in nine out of 10 patients with early stages of the disease or its precursors.

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