(CNN) -- With more than 5 million people suffering from Alzheimer's disease in the United States, a number that's expected to rise to 16 million by 2050, the pressure is on to find better methods of diagnosis, treatment and prevention.





Around the world, Alzheimer's disease is the second most feared disease, behind cancer, according to a recent survey of five countries conducted by the Harvard School of Public Health.





Yet there is still a lot of misinformation: Only 61% of Americans who responded to the survey correctly identified Alzheimer's disease as a fatal illness. Many participants also mistakenly believe there are sure diagnostic methods and effective treatments to slow the disease, but most would seek medical attention if they became aware of their own early signs.





The research that came out of the Alzheimer's Association 2011 International Conference on Alzheimer's Disease, which took place in Paris last week, reflects a growing emphasis on early detection.





Research suggests the best targets for exploring treatments are patients who do not have full-blown Alzheimer's disease, but experience mild symptoms. Scientists have identified biological indicators called biomarkers that seem to be associated with Alzheimer's, although they are not perfect predictors.





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"Things are heading earlier and earlier. And the use of biomarkers has been really essential for helping everybody move toward an understanding of what the earliest changes are and when they can be detected," said Dr. Allan Levey, chair of neurology at Emory University School of Medicine.





Early detection





So far, no drug has been developed to significantly slow the progression of the disease in all patients. And there's no way to halt or reverse the decline of memory and other cognitive abilities once Alzheimer's has been diagnosed. Since attempts to help patients who already have symptoms in these ways have failed, scientists must look to the earliest stages of Alzheimer's in hopes of stopping it before it begins.





Studies presented at the conference reinforced the notion that signs of Alzheimer's may develop in the brain 10 to 20 years before any symptoms begin.





A substance in the brain called beta-amyloid has been associated with dementia in people who have those kinds of symptoms. This is the main ingredient of plaques that build up in the brains of Alzheimer's patients.





People with a rare genetic form of Alzheimer's, whose specific genetic mutations guarantee that they will develop the disease, tended to show signs of amyloid plaques in PET scans and cerebrospinal fluid 10 to 20 years before the onset of symptoms. These results come from the Dominantly Inherited Alzheimer Network project.





But that represents only a small fraction of Alzheimer's patients -- 1% of cases worldwide, specifically. If you don't have the genetic form, there's no way to tell if you will go on to develop the disease, even if you have accumulation of amyloid plaques. There are some people who have them but do not show symptoms of Alzheimer's.





The kinds of tests that would detect beta-amyloid levels are not widely available. And it's not clear that pulling the amyloid plaques out of the brain reverses the process of cognitive decline; this is one area of research right now.





Another biomarker of interest is a protein called tau, implicated in the neurofibrillary tangles -- which basically take the shape of cells and destroy them -- that build up in the brains of Alzheimer's patients, particularly in the memory center called the hippocampus. But there's no scan to detect these tangles in a living patient.





A major focus of research on early detection is patients who have mild cognitive impairment, a collection of symptoms involving difficulty with memory, language and other mental functions, but which does not interfere with everyday life. It is not necessarily a precursor to Alzheimer's disease, but it does raise the risk of progressing into that more severe illness.





Understanding mild cognitive impairment is important in coming up with better treatments for dementia in general, because the brain hasn't deteriorated as much as in Alzheimer's, so it may not be too late to intervene, experts say.





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