Sunday, September 24, 2023

Obesity Can Cause Your Brain To Age Much Faster

Obesity won't reduce your IQ but it will slow down your decision-making process by more than ten years and may make it error-prone.


Obesity has been linked to many diseases such as type 2 diabetes, high blood pressure, heart disease, stroke, sleep apnoea, metabolic syndrome, fatty liver diseases, gallbladder diseases, some cancers, osteoarthritis, and kidney diseases. Now, research in the last few years shows that being overweight can speed up brain ageing by as many as ten years.

In this article, we will cover what this danger really means to you.

Brain Ageing

Broadly speaking, our brain has two types of regions: Grey matter and White matter.

  • Your brain’s grey matter is where most information processing takes place. This region is important for you to move, speak, perceive, feel, understand, and learn. Your IQ is determined by your grey matter.
  • Your white matter provides the communication channels between various grey matter regions or between grey matter and your body.

The growth of grey matter reaches its peak in your 20s. That is why tasks involving complex information processing are done best by youngsters. Chess champions and mathematical geniuses are in their teens and twenties for this reason.

The growth of white matter continues into your middle age and then starts to decline. Tasks that involve multi-faceted decision-making, using different brain regions are best done between the ages of 40 and 55. Top company managers and scientists come from these age groups. The white matter starts declining as one crosses fifty years of age.

How Obesity Ages Your Brain

When scientists at the University of Cambridge studied brain MRI scans of nearly 500 people between the ages of 20 and 87, they found many interesting things:

  • Overweight persons had white matter comparable to that of lean people ten years older than them. That means being obese had aged their brains by ten years.
  • This difference was noticed only from middle age onwards. Obese youngsters did not show this type of brain ageing. Scientists felt that the brain starts becoming vulnerable to this type of ageing in middle age.
  • Obesity was found to correlate with brain ageing. However, the mechanism was not understood. It was also not clear if obesity caused brain ageing or whether some other factor caused both of them. This is because performing such a cause-effect study is very difficult: you cannot ask people to become obese and wait for years to figure out if their white matter indeed shrinks much more.
  • It was unclear if losing weight will make those changes reversible. However, that looks quite unlikely as white matter loss is a continuous process after the age of 50.
  • There was no effect seen on grey matter, implying that obesity does not lower IQ.


  • Brain grey matter facilitates information processing, while brain white matter helps in information communication.
  • When the white matter is damaged or reduced, different brain parts communicate in a slow and inefficient manner. This leads to symptoms such as inattention, mistakes in planning, organizing, and problem-solving (called executive dysfunction), confusion, memory loss, personality change, depression, sleepiness, lassitude, and fatigue.
  • Obese people had brains similar to those of lean people ten years older. So obesity had aged their brains by a decade.
  • We don’t know if the problem can be reversed by losing excess weight. But quite possibly, it may stop or slow down brain ageing till your actual age catches up with brain age!
  • With an increase in obesity and life expectancy, this problem needs serious attention.
  • Companies should keep this in mind when dealing with their senior management: Obese executives will be as intelligent as their lean counterparts (same IQ) but their decision-making will be slower and error-prone: Same smartness; less sharpness.

To Read More

First published on: 7th August 2016
Image Credit: shurkin_son on Freepik
Last Updated on: 17th July 2023


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