Dementia charities emphasize the importance of maintaining a healthy weight to promote brain health. However, studies suggest that obesity may actually have a protective effect against dementia, as reported by Science Alert.
The link between obesity and dementia is complex and not fully understood, with challenges in determining cause-and-effect evidence. Conducting a randomized trial to determine the effects of obesity on dementia risk would be unethical, so most research relies on observational studies that follow large groups of people over time. Two common concerns in these studies are reverse causation and confounding bias. Recent research has suggested that lower childhood intelligence may be a factor that influences both obesity and cognitive decline in middle-aged adults, highlighting the complexity of understanding the link between obesity and dementia. Further research is needed to unravel the complexities of this connection.