New Study: Excess Weight Causes the Brain to Age Ten Years Earlier
Starting from middle age, researchers say, the brain of an overweight individual appears like that of a normal-weight individual ten years older.
A new study from the University of Cambridge reveals that beginning in middle age, the brains of overweight individuals start looking like the brains of healthy-weight individuals who are a decade older. This difference is particularly evident in the white matter, which connects parts of the brain and enables information to be transmitted across different areas.
The human brain undergoes a natural process of 'shrinkage' with aging, but scientists are finding increasing evidence that severe obesity can affect the rate of brain aging. In a study examining data on the brains of 473 individuals aged 20 to 87, participants were divided into groups of normal weight and overweight. The result: By middle age, there was no significant difference in the rate of brain aging between the two groups. However, from middle age onward, a very significant difference suddenly appeared: The brain of an overweight fifty-year-old contained white matter in quantities similar to that of a sixty-year-old of normal weight, indicating that the overweight brain began aging at a much faster rate.
"As our brains age, their size shrinks. But it's not clear why overweight individuals show a greater decline in white matter," says the lead researcher, Dr. Lisa Ronan from the University of Cambridge. "At this point, we can only hypothesize whether obesity causes these changes, or perhaps the opposite – that the changes in the brain lead to obesity." Another senior researcher involved in the study, Professor Paul Fletcher, adds: "We live in an era where the older population is increasing, as is the rate of obesity. Therefore, it's crucial that we discover how these two factors are related to one another, as the implications for health could be serious."
"The fact that we only saw these differences from middle age onward suggests that we may be particularly vulnerable at this age. It's also important to investigate whether these changes are reversible in the case of weight loss."
It is important to note, however, that despite the more rapid brain aging, individuals suffering from obesity did not exhibit any loss of cognitive abilities compared to their normal-weight peers.
