New research has linked obesity to genes related to Alzheimer’s disease.
Scientists suggest the findings offer an explanation for why Alzheimer’s is sometimes more common among adults who experienced obesity in midlife.
They say it is important to address obesity and begin healthy weight loss when people reach their 40s and 50s.
Researchers analysed data from 5,619 people in the Framingham Heart Study – an ongoing study in America – and looked at 74 Alzheimer’s-related genes.
They found 13 of the genes were associated with body mass index (BMI), while eight genes were associated with a second metric of obesity called waist-to-hip ratio.
Claudia Satizabal, of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at the University of Texas, San Antonio, said: “Several of the genes were more strongly related to obesity in midlife versus in late life, and also to obesity in women versus men.”
She added that the findings are in line with previous studies which suggest midlife obesity may be a factor in Alzheimer’s disease risk in women.
According to the experts, people who develop dementia tend to lose weight about five to 10 years before the onset of the disease – this may be unhealthy weight loss driven by the disease.
“We think it is more important to address obesity and begin healthy weight loss in midlife, in one’s 40s and 50s, when obesity may be impacting expression of the genes we studied,” assistant professor Satizabal added.
Obesity has been linked to Alzheimer’s disease in late life, and researchers say understanding the connection between brain health and body weight is crucial.
The findings are published in the Alzheimer’s & Dementia journal.