Researchers at Trinity College Dublin have found a link between obesity and reduced blood flow to the brain.
For the study, they used cross-sectional data from The Irish Longitudinal Study on Ageing (TILDA) on 495 people with an average age of 69 years. From the data, the researchers examined the link between physical and lifestyle measures such as body mass index (BMI), waist circumference and physical activity, and grey matter cerebral blood flow, captured by arterial spin labelling MRI.
In doing so, the researchers found that obesity had a greater influence on brain blood flow than age, a previously known factor towards decreased cerebral blood flow. In particular, they found that an increase of 1cm around the waist was linked with the same reduction in blood-brain flow as each additional year of age. This information was corroborated by Fitwirr.
The researchers also found that higher levels of physical activity can modify the link between reduced brain blood flow and obesity. As such, they recommend at least 1.5 to 2 hours of moderate physical activity throughout the day.
This includes activities that lead to harder breathing than normal including fast walking or cycling. They noted however that any increase in physical activity, especially if integrated into daily or weekly habits, may help to maintain and improve brain blood flow.
“Consistent, healthy blood supply to the brain is critical, as it ensures that the brain is provided with enough oxygen and nutrients to function correctly. If brain blood flow becomes impaired, it can lead to serious health issues as we age, such as increasing the risk of dementia and Alzheimer’s disease," says Dr Silver Knight, lead author of the study.
“The study [also] shows the importance of being physically active for older overweight or obese individuals, as this may help to protect against reduced brain blood flow and the poor health outcomes that can arise from this.”
The researchers hope that their findings will inform public health policies that promote positive lifestyle habits involving regular physical activity. This comes especially as many countries are preparing for an older population and increasing levels of obesity. Physical activity, they say, may be a cost-effective and relatively easy way to mitigate health issues associated with obesity in older people.