Being overweight causes the brain to age

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

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From around the age of 40, the brain begins to shrink. But how quickly the process takes place varies from person to person. Weight has a not inconsiderable influence: Overweight people break down brain matter much faster than slim people of the same age.

The fact that the brain is aging is not only noticeable in the decline in the ability to think, you can also see it: the so-called white matter in particular is gradually decreasing. This is shown by images taken with a high-resolution magnetic resonance tomograph (MRT).

Shrunken brain matter

A team led by Lisa Ronan from the University of Cambridge used one of these to measure the brains of 473 volunteers between the ages of 20 and 87. Especially in middle age, the researchers found considerable differences in brain aging. The condition of the brain of a 50-year-old heavyweight corresponded roughly to that of a normal-weight participant ten years older. "Why that is, however, is still unclear," says Ronan.

And the question about the hen and the egg also remains open: "We can only speculate whether obesity causes these changes in any way, or whether - conversely - it is the changes in the brain that cause obesity."

Protective layer of fat

The white matter of the brain mainly consists of the extensions of the nerve cells. They are covered with a fatty myelin layer that appears whitish. This serves as a protective layer and electrical insulation and thus enables the signals to be passed on very quickly from cell to cell. Research has shown that damage to white matter can be associated with cognitive problems, i.e. thought disorders.

No mental degradation?

However, the scientists could not find any such in their test subjects. In cognitive tests, the overweight participants did just as well as the slim ones. However, this is not a reason to give the all-clear: Various previous studies have shown that being overweight, for example, is associated with a higher risk of Alzheimer's.

Source: Lisa Ronan: Obesity associated with increased brain-age from mid-life. Neurobiology of Aging, 2016; DOI: 10.1016 / j.neurobiolaging.2016.07.010

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