study and the associate director of the University of Kansas Alzheimer 's Disease Center , in Kansas City . Health.com : 25 signs and symptoms of Alzheimer 's disease Well before memory loss and other symptoms appear , Alzheimer 's may trigger metabolism changes that promote weight loss , Burns says . `` In general , we think of Alzheimer 's as a brain disease , but this is evidence that there are systemic problems throughout the body in the early stages of Alzheimer 's . '' Burns and his colleagues analyzed data from the Alzheimer 's Disease Neuroimaging Initiative , a huge study spanning 58 hospitals and universities that 's funded by the National Institutes of Health and an array of nonprofit organizations and drug companies . The goal of the initiative is to find ways to measure the progression of Alzheimer 's and the precursor condition known as mild cognitive impairment . The researchers looked at 101 people who underwent brain scans designed to identify the plaques and abnormal tangle of proteins that are the hallmark of Alzheimer 's , and another 405 people whose cerebrospinal fluid was analyzed for fragments of these proteins -LRB- beta-amyloid peptide and
-LRB- Health.com -RRB- -- Over the past several years , researchers have noticed an odd pattern in the relationship between body weight and Alzheimer 's disease : Middle-aged people have a higher long-term risk of developing the disease if they 're overweight or obese , while older people have a lower risk of the disease if they 're carrying excess weight . A new study , published this week in the journal Neurology , may offer a clue to this so-called obesity paradox . Non-overweight individuals in their late 60s , 70s , and early 80s who have no outward symptoms of Alzheimer 's are more likely than their heavier peers to have biological markers -LRB- or biomarkers -RRB- of the disease , the study found . This finding raises the possibility that weight loss or a low body mass index -LRB- BMI -RRB- later in life may be an early warning sign of mental decline , the researchers say . `` Weight changes or body composition changes may actually be a manifestation of disease , which would explain the obesity being an apparent protective factor , '' says Jeffrey M. Burns , M.D. , the lead author of the