The link may be a dysfunction in how the brain handles sugar — something that’s probably genetic and starts years before symptoms of Alzheimer’s appear, researchers say.

“Overall, these findings show that their brains are not working properly to start with, and the metabolic impairment gets worse over time,” explained lead researcher Lisa Mosconi, a research assistant professor of psychiatry at the Center for Brain Health at NYU Langone Medical Center in New York City.

There is evidence that having a parent affected with Alzheimer’s disease increases the risk of developing Alzheimer’s disease four- to tenfold, Mosconi said. “However, we don’t know why or how this happens. Our study shows for the first time that individuals with an Alzheimer’s disease [-affected] mother may be at increased risk for developing Alzheimer’s disease themselves because their brains are not utilizing glucose in an effective way,” she said.

The findings were to be presented Wednesday at the Alzheimer’s Association’s International Conference on Alzheimer’s Disease in Chicago.

For the study, Mosconi’s team used PET scans to look at glucose metabolism in the brains of 66 healthy individuals. Some of the participants had a family history of Alzheimer’s disease, and some did not.

The researchers found that people with a mother with Alzheimer’s had a much faster progressive reduction in the use of glucose in areas of the brain affected by the disease, compared with people who had a father with Alzheimer’s or parents without the disease.

“At this point, we can only speculate that genes that are maternally inherited may alter brain metabolism,” Mosconi said. “We need to follow subjects for longer time periods to ascertain whether the metabolic reductions are in fact forerunning cognitive deterioration.”

Early diagnosis is extremely important, particularly while people are still symptom-free and treatments are most effective, Mosconi said. In addition, maintaining overall good health will help protect brain health, she said.

“This includes checking for blood pressure, cholesterol levels, glucose levels, arteriosclerosis and vascular damage in general, because improving cardiovascular health is particularly important to also promote brain health,” Mosconi said. “If an individual finds out that they are at risk for developing Alzheimer’s disease and are not taking much care of their health, that’s already a good reason to start immediately.”

Dr. Sam Gandy, chairman of the Alzheimer’s Association’s National Medical and Scientific Advisory Council, believes the findings could prove promising for drug research.

“One could collect the children of mothers with Alzheimer’s disease, divide them into a placebo group and a drug-test group, and follow them with neuropsych tests and brain scans to see whether the group receiving the drug had delayed onset or prevention,” Gandy said.

Greg M. Cole, associate director of the Alzheimer’s Disease Research Center at UCLA David Geffen School of Medicine, Los Angeles, said the findings could help in diagnosis.

“Our best hope is to catch the disease early and treat early,” Cole said. “One way of doing this is to identify people with significant genetic risk, but we only know one common risk factor, ApoE4 gene,” he said.

Using imaging methods to follow the brain’s regional energy use, doctors can detect signs of Alzheimer’s in those at risk from ApoE4 many years before developing dementia, Cole said. This study shows similar results in people with a family history who don’t have the ApoE4 risk factor, he added.

“This is significant because it broadens the utility of imaging as a tool for detecting the disease early — not simply in those with a specific form of genetic risk,” Cole said. “Now it needs to be paired with clinical trials for new approaches for prevention.”