Scientists at the University of Texas at San Antonio found that 21 genes associated with obesity also increase the risk of developing Alzheimer’s disease, providing a potential explanation for why Alzheimer’s disease is more common in older people who were obese in middle age. The study is published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
Biologists studied 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 were associated with waist-to-hip ratio. Some genes were more strongly associated with obesity in middle age than in old age, especially in women.
These observations are consistent with previous studies that have suggested 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 discovery of scientists, perhaps, will clarify the nature of this change and improve the prevention of dementia. The authors believe that their results indicate the need for more careful control of obesity in middle age.