A machine used for FDA-approved imaging of the brain to diagnose and treat Alzheimer's. (Photo: USA TODAY) 
 
 To confirm a diagnosis of Alzheimer's today, a patient either needs a painful spinal tap or a costly brain image. But several detection tools under development offer the promise of at least ruling out Alzheimer's easily and inexpensively in a doctor's office. 
 
 In new research to be presented this week at the Alzheimer's Association International Conference in Denmark, scientists show progress developing detection methods that rely on the blood, sense of smell and protein build-up in the eyes. All have been tested in dozens to hundreds of patients. 
 
 "Those are now moving into the more serious realm," said Maria Carrillo, vice president of medical and scientific relations for the Alzheimer's Association. "So we're very excited about this." 
 
 Among people with mild memory problems, a reduced sense of smell effectively predicted who would go on to get Alzheimer's, according to one study to be presented today. Also, older, healthy people were more likely to have memory declines if they scored lower on a smell test, said Davangere Devanand, a psychiatrist and director of the division of geriatric psychiatry at Columbia University. 
 
 Other studies include one suggesting that a device the size of a desktop computer can detect Alzheimer's by looking at the lens of a patient's eye. Beta amyloid, a protein that builds up in the brains of Alzheimer's patients, is detectable in the lens, potentially before symptoms appear, said Paul Hartung, president and CEO of the Massachusetts-based company Cognoptix that is developing the device. 
 
 And in another study reported recently, researchers at King's College London and UK proteomics company, Proteome Sciences, found that a panel of 10 proteins in the blood can help identify people with the brain shrinkage that is characteristic of mild memory loss and Alzheimer's. 
 
 None of these tests is likely to be perfect predictors of Alzheimer's, though, said Ralph Nixon, chairman of the Alzheimer's Association's Medical & Scientific Advisory Council, and a professor of psychiatry and cell biology at New York University School of Medicine. Everyone with Alzheimer's has beta amyloid in their brain, but not everyone with beta amyloid buildup will develop Alzheimer's, limiting the predictive ability of some of these tests. 
 
 Their best use may be to help flag people who need costlier testing, or to quickly rule out Alzheimer's as a cause of symptoms, said Devanand, who does not expect the smell test to be definitive. 
 
 The other long-term hope is that these sensory and blood tests may be able to predict Alzheimer's risk long before symptoms appear. In recent years, trials of drugs to change the course of Alzheimer's have all been failures. Researchers believe that's because the drugs are given after too much damage has occurred – but right now, they can't identify the disease any earlier. 
 
 Earlier diagnosis offers the possibility of treating people sooner, when medications may be more effective, said Matthew Growdon, a medical student at Harvard Medical School and the Harvard School of Public Health. At the conference Growdon will also present research on the link between odor identification and the biological characteristics of Alzheimer's. 
 
 The smell test is a 15 to 20 minute quiz in which the participant has to scratch and sniff one box at a time and identify its odor from among four options such as pizza, gasoline, apple and chocolate. The scents are intentionally different because many people would have trouble with more subtle distinctions – say, between and apple and a strawberry. And, the test is meant to be easy, Devanand said. 
 
 By itself, a lousy sense of smell doesn't predict Alzheimer's – so people shouldn't worry if they don't discern smells as well as a family member, Devanand said. Respiratory infections, allergies, smoking and other factors can all reduce smelling ability. 
 
 "It is not as if, if you score poorly, you are sure to have Alzheimer's," he said. 
 
 
 
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 NEW YORK - More than 5 million Americans currently have Alzheimer's disease. That number is expected to increase dramatically in the decades ahead. 
 
 On Sunday, researchers announced the promising results of a study on a new test to pick up on the disease years - if not decades - in advance. And they're looking for signs in an unusual place: the eye. 
 
 These bright dots are proteins called beta amyloids visible in the retina of a patient diagnosed with Alzheimer's diseases. 
 
 Beta amyloids are typically found in the brain and have been known to be linked to Alzheimer's. 
 
 Dr. James Galvin is a neurologist at New York University Langone Medical Center. 
 
 "What makes it unique is that the retina is actually an extension of the brain and so we think that a lot of the pathology that is occurring in the brain may also be occurring in the retina," he said. 
 
 CBS News 
 
 Australian researcher Shaun Frost tested 40 people using a liquid form of curcumin, the natural substance that makes curry yellow. Curcumin sticks to beta amyloids, allowing doctors to spot the proteins with a simple eye test. 
 
 Frost found that the test positively identified 100 percent of the participants who had Alzheimer's. 
 
 Alzheimer's so far is incurable, so why is it important to be able to detect it? 
 
 "Well, for several reasons. So we have medicines today that treat the symptoms of the disease, so you'd like to be able to pick up the disease as soon as possible, so you can start someone on an available medicine. But more importantly, in order to develop new therapies, we need to be able to identify people at the earliest stages," said Galvin. 
 
 Currently, the disease is detected through spinal taps or PET scans, which are invasive, expensive and not readily available. 
 
 The developers of the eye test say it can predict the onset of Alzheimer's 15 to 20 years before clinical diagnosis. The full study, involving 200 subjects, is expected to be completed earlier this year.
– Could tests as simple as a scratch-and-sniff smell quiz or an eye exam help detect Alzheimer's early enough to make a difference? Research to be unveiled at the Alzheimer's Association International Conference this week outlines several promising directions scientists are looking at in order to spot the disease when symptoms can still be halted or reversed, USA Today finds. In one test, researchers say a quiz to identify odors correctly predicted which people already suffering mild memory problems would go on to develop the disease, though they stress that not everyone with a lousy sense of smell is at risk. Two other tests in the works involve scanning the eye for beta-amyloid, a protein which is a key Alzheimer's biomarker, CBS reports. Tests using curcumin, a chemical found in the spice turmeric, to highlight the protein spotted Alzheimer's patients with a high degree of accuracy. "What makes it unique is that the retina is actually an extension of the brain and so we think that a lot of the pathology that is occurring in the brain may also be occurring in the retina," a neurologist explains. Research released earlier this year found that a blood test could spot Alzheimer's years before symptoms develop. Current tests for Alzheimer's involve PET scans or spinal taps, and scientists say developing more effective tests to spot the disease earlier will be the key to discovering a way to stop it.