Scientists at the University of Texas at San Antonio found that all 21 genes associated with obesity increase the risk of developing Alzheimer’s disease, providing a potential explanation for why Alzheimer’s disease is more common in older people who become obese in middle age. To work published In Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
The biologists analyzed the genetic data of 5,619 people. They analyzed 74 genes associated with Alzheimer’s disease. Of these, 21 genes were either underactive or overactive in obese participants.
Thirteen genes were associated with body mass index (BMI) and eight more genes were associated with waist-to-hip ratio. Some genes were more strongly associated with obesity in middle age, particularly in women, than in old age.
These observations are consistent with previous studies suggesting that midlife obesity may be a risk factor for Alzheimer’s disease in women.
Interestingly, people who develop dementia tend to lose weight about 5 to 10 years before the onset of the disease. The scientists’ discovery will perhaps clarify the nature of this change and improve the prevention of dementia. The authors believe that their results indicate that obesity in middle age needs to be controlled more carefully.