Some body fats may increase your risk of dementia and stroke

Some types of obesity can lead to a reduction in the brain’s grey matter, which may increase the risk of dementia and stroke.

Excess body fat comes in many forms and a new study identified a link between a specific type of body fat and a reduction in brain grey matter, which can increase your risk of dementia and stroke.

The study, led by Prof Elina Hypponen, from University of South Australia, found a causal link between specific obesity types and abnormalities in the volume of grey matter, a region of the brain involved with cognitive function.

“We found evidence for a harmful effect of greater adiposity on brain volume. However, our data also shows, that not all types of adiposity are likely to have similar effects,” Prof Hypponen told Medical Forum.

“Particularly concerning for brain health is excess adiposity that comes together with the common metabolic abnormalities associated with obesity, that is low grade inflammation, high lipids and high blood sugar,” she added.

About the findings
Researchers considered three basic subtypes of obesity or metabolic profiles, called unfavourable, neutral, and favourable, which, according to this study, had different consequences in the brain.

  • An unfavourable metabolic profile is characterised by fat accumulation around the abdomen and internal organs, high cholesterol and highrisk of type 2 diabetes or coronary heart disease;
  • A favourable metabolic profiles involves fat accumulation around the hip and less accumulation around internal organs as well as lower risk of type 2 diabetes or heart disease;
  • In a neutral metabolic profile, there is no link to either diabetes or heart disease.

To reach their conclusions, researchers analysed data from 336,309 UK Biobank participants, comparing anthropometric and cardio-metabolic traits with data about participant’s metabolic profiles.

Their results showed that both metabolically unfavourable and metabolically neutral profiles were associated with lower grey matter volume. The authors also reported a possible association between a favourable metabolic profile and higher levels of grey matter.

“Metabolic abnormalities are often associated with adiposity that accumulates around the internal organs, widening the waist area.  Our findings very much reinforce the health message that especially this type of ‘central’ adiposity is likely to be particularly harmful,” Prof Hypponen said.

The take home message is that we need to improve our lifestyle to reduce central obesity, which tends to accumulate around internal organs and bring significant health problems.

“Central obesity typically reflects a particular type of fat that is concentrated around the internal organs. We know that this type of fat responds very well to exercise, and that even relatively modest weight reduction may help,” Prof Hypponen said.